diff --git a/.brazil.json b/.brazil.json
index 2d2e217845..7de96869c6 100644
--- a/.brazil.json
+++ b/.brazil.json
@@ -5,10 +5,12 @@
 
     "com.squareup.okhttp3:okhttp-coroutines:5.*": "OkHttp3Coroutines-5.x",
     "com.squareup.okhttp3:okhttp:5.*": "OkHttp3-5.x",
+    "com.squareup.okhttp3:okhttp-jvm:5.*": "OkHttp3-5.x",
     "com.squareup.okio:okio-jvm:3.*": "OkioJvm-3.x",
     "io.opentelemetry:opentelemetry-api:1.*": "Maven-io-opentelemetry_opentelemetry-api-1.x",
     "io.opentelemetry:opentelemetry-extension-kotlin:1.*": "Maven-io-opentelemetry_opentelemetry-extension-kotlin-1.x",
     "org.slf4j:slf4j-api:2.*": "Maven-org-slf4j_slf4j-api-2.x",
+    "aws.sdk.kotlin.crt:aws-crt-kotlin:0.10.*": "AwsCrtKotlin-0.10.x",
     "aws.sdk.kotlin.crt:aws-crt-kotlin:0.9.*": "AwsCrtKotlin-0.9.x",
     "aws.sdk.kotlin.crt:aws-crt-kotlin:0.8.*": "AwsCrtKotlin-0.8.x",
     "com.squareup.okhttp3:okhttp:4.*": "OkHttp3-4.x",
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000000..968d241bfe
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: gradle
+    directory: /
+    schedule:
+      interval: daily # means every _weekday_ (Monday through Friday)
diff --git a/.github/workflows/artifact-size-metrics.yml b/.github/workflows/artifact-size-metrics.yml
index 815662b755..fce601e0f5 100644
--- a/.github/workflows/artifact-size-metrics.yml
+++ b/.github/workflows/artifact-size-metrics.yml
@@ -1,6 +1,6 @@
 name: Artifact Size Metrics
 on:
-  pull_request:
+  pull_request_target:
     types: [ opened, synchronize, reopened, labeled, unlabeled ]
     branches:
       - main
@@ -40,7 +40,7 @@ jobs:
       - name: Put Artifact Size Metrics in CloudWatch
         run: ./gradlew putArtifactSizeMetricsInCloudWatch -Prelease=${{ github.event.release.tag_name }}
   size-check:
-    if: github.event_name == 'pull_request'
+    if: github.event_name == 'pull_request_target'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Sources
@@ -70,10 +70,10 @@ jobs:
       - name: Analyze Artifact Size Metrics
         run: ./gradlew analyzeArtifactSizeMetrics
         working-directory: smithy-kotlin
+
       - name: Show Results
         uses: awslabs/aws-kotlin-repo-tools/.github/actions/artifact-size-metrics/show-results@main
-        with:
-          working-directory: smithy-kotlin
+
       - name: Evaluate
         if: ${{ !contains(github.event.pull_request.labels.*.name, 'acknowledge-artifact-size-increase') }}
         working-directory: smithy-kotlin
diff --git a/.github/workflows/changelog-verification.yml b/.github/workflows/changelog-verification.yml
index 457764177f..995c03843c 100644
--- a/.github/workflows/changelog-verification.yml
+++ b/.github/workflows/changelog-verification.yml
@@ -4,7 +4,7 @@ permissions:
   id-token: write
 
 on:
-  pull_request:
+  pull_request_target:
     types: [ opened, synchronize, reopened, labeled, unlabeled ]
     branches:
       - main
@@ -13,6 +13,7 @@ on:
 jobs:
   changelog-verification:
     runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login != 'dependabot[bot]' # no changelogs for Dependabot version bumps
     steps:
       - name: Configure AWS Credentials
         uses: aws-actions/configure-aws-credentials@v4
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index fc8d7af115..5343a8bf01 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -45,6 +45,10 @@ jobs:
           distribution: 'corretto'
           java-version: 17
           cache: 'gradle'
+      - name: Configure Gradle
+        uses: awslabs/aws-kotlin-repo-tools/.github/actions/configure-gradle@main
+        with:
+          working-directory: 'smithy-kotlin'
 
       - name: Build and Test on JVM
         working-directory: ./smithy-kotlin
diff --git a/.github/workflows/kat-transform.yml b/.github/workflows/kat-transform.yml
index b4efd9e5a9..9ed7e3ecca 100644
--- a/.github/workflows/kat-transform.yml
+++ b/.github/workflows/kat-transform.yml
@@ -1,7 +1,7 @@
 name: Kat Transform
 
 on:
-  pull_request:
+  pull_request_target:
     types: [ opened, synchronize, reopened, labeled, unlabeled ]
     branches:
       - main
diff --git a/.github/workflows/merge-main.yml b/.github/workflows/merge-main.yml
index db1df3a142..ae4af7a055 100644
--- a/.github/workflows/merge-main.yml
+++ b/.github/workflows/merge-main.yml
@@ -12,4 +12,4 @@ jobs:
         uses: awslabs/aws-kotlin-repo-tools/.github/actions/merge-main@main
         with:
           ci-user-pat: ${{ secrets.CI_USER_PAT }}
-          exempt-branches: # Add any if required
\ No newline at end of file
+          exempt-branches: # Add any if required
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ad34f18d2e..06450764f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,31 @@
 # Changelog
 
+## [1.5.3] - 07/28/2025
+
+### Features
+* [#1320](https://github.com/smithy-lang/smithy-kotlin/issues/1320) Enable configuration of timeouts for calls and attempt
+
+## [1.5.2] - 07/24/2025
+
+### Miscellaneous
+* [#1339](https://github.com/smithy-lang/smithy-kotlin/issues/1339) Add documentation for OkHttp4Engine when using Android with R8 / ProGuard
+
+## [1.5.1] - 07/17/2025
+
+## [1.5.0] - 07/17/2025
+
+### Features
+* Upgrade to Kotlin 2.2.0
+* [#1413](https://github.com/awslabs/aws-sdk-kotlin/issues/1413) ⚠️ **IMPORTANT**: Refactor endpoint discoverer classes into interfaces so custom implementations may be provided
+
+### Fixes
+* [#1311](https://github.com/smithy-lang/smithy-kotlin/issues/1311) Reimplement idle connection monitoring using `okhttp3.EventListener` instead of now-internal `okhttp3.ConnectionListener`
+* [#1608](https://github.com/awslabs/aws-sdk-kotlin/issues/1608) Switch to always serialize defaults in requests. Previously fields were not serialized in requests if they weren't `@required` and hadn't been changed from the default value.
+* [#1413](https://github.com/awslabs/aws-sdk-kotlin/issues/1413) Favor `endpointUrl` instead of endpoint discovery if both are provided
+
+### Miscellaneous
+* Add telemetry provider configuration to `DefaultAwsSigner`
+
 ## [1.4.23] - 07/15/2025
 
 ## [1.4.22] - 07/02/2025
diff --git a/build.gradle.kts b/build.gradle.kts
index bdec55641a..7e5c097678 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -2,8 +2,8 @@
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
+import aws.sdk.kotlin.gradle.dsl.configureJReleaser
 import aws.sdk.kotlin.gradle.dsl.configureLinting
-import aws.sdk.kotlin.gradle.dsl.configureNexus
 import aws.sdk.kotlin.gradle.util.typedProp
 
 buildscript {
@@ -14,6 +14,12 @@ buildscript {
         classpath(libs.kotlinx.atomicfu.plugin)
         // Add our custom gradle build logic to buildscript classpath
         classpath(libs.aws.kotlin.repo.tools.build.support)
+        /*
+        Enforce jackson to a version supported both by dokka and jreleaser:
+        https://github.com/Kotlin/dokka/issues/3472#issuecomment-1929712374
+        https://github.com/Kotlin/dokka/issues/3194#issuecomment-1929382630
+         */
+        classpath(enforcedPlatform("com.fasterxml.jackson:jackson-bom:2.19.2"))
     }
 }
 
@@ -79,7 +85,7 @@ dependencies {
 }
 
 // Publishing
-configureNexus()
+configureJReleaser()
 
 // Code Style
 val lintPaths = listOf(
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
index f144c54f9f..9b25eaaa29 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
@@ -40,7 +40,27 @@ class RegionSupport : KotlinIntegration {
             name = "region"
             symbol = KotlinTypes.String.toBuilder().nullable().build()
             documentation = """
-                The region to sign with and make requests to.
+                The AWS region to sign with and make requests to. When specified, this static region configuration
+                takes precedence over other region resolution methods. 
+                
+                The region resolution order is:
+                1. Static region (if specified)
+                2. Custom region provider (if configured)
+                3. Default region provider chain
+            """.trimIndent()
+        }
+
+        val RegionProviderProp: ConfigProperty = ConfigProperty {
+            name = "regionProvider"
+            symbol = RuntimeTypes.SmithyClient.Region.RegionProvider
+            documentation = """
+                An optional region provider that determines the AWS region for client operations. When specified, this provider
+                takes precedence over the default region provider chain, unless a static region is explicitly configured.
+              
+                The region resolution order is:
+                1. Static region (if specified)
+                2. Custom region provider (if configured)
+                3. Default region provider chain
             """.trimIndent()
         }
     }
@@ -57,7 +77,7 @@ class RegionSupport : KotlinIntegration {
         return supportsSigv4 || hasRegionBuiltin || isAwsSdk
     }
 
-    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> = listOf(RegionProp)
+    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> = listOf(RegionProp, RegionProviderProp)
 
     override fun customizeEndpointResolution(ctx: ProtocolGenerator.GenerationContext): EndpointCustomization =
         object : EndpointCustomization {
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 48d47a7c18..853ed38a55 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -11,13 +11,23 @@ import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AbstractQueryFor
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AwsHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RenderingContext
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
-import software.amazon.smithy.kotlin.codegen.model.*
-import software.amazon.smithy.kotlin.codegen.rendering.protocol.*
-import software.amazon.smithy.kotlin.codegen.rendering.serde.*
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+import software.amazon.smithy.kotlin.codegen.model.getTrait
+import software.amazon.smithy.kotlin.codegen.model.hasTrait
+import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.protocol.toRenderingContext
+import software.amazon.smithy.kotlin.codegen.rendering.serde.FormUrlSerdeDescriptorGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.StructuredDataParserGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.StructuredDataSerializerGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.XmlParserGenerator
 import software.amazon.smithy.model.shapes.*
-import software.amazon.smithy.model.traits.*
+import software.amazon.smithy.model.traits.XmlFlattenedTrait
+import software.amazon.smithy.model.traits.XmlNameTrait
 
 /**
  * Handles generating the aws.protocols#awsQuery protocol for services.
@@ -45,7 +55,7 @@ class AwsQuery : QueryHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponse)
     }
 }
 
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index 10be8bfc6e..b84f22f442 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -10,7 +10,10 @@ import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AbstractQueryFormUrlSerializerGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RenderingContext
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.getTrait
 import software.amazon.smithy.kotlin.codegen.model.isNullable
@@ -39,7 +42,7 @@ class Ec2Query : QueryHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseEc2QueryErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseEc2QueryErrorResponse)
     }
 }
 
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 7c1f45b92c..c7c834c317 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -63,7 +63,7 @@ open class RestXml : AwsHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponse)
     }
 }
 
diff --git a/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt
new file mode 100644
index 0000000000..2df3e519f0
--- /dev/null
+++ b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt
@@ -0,0 +1,73 @@
+package software.amazon.smithy.kotlin.codegen.aws.customization
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.model.expectShape
+import software.amazon.smithy.kotlin.codegen.rendering.ServiceClientConfigGenerator
+import software.amazon.smithy.kotlin.codegen.test.*
+import software.amazon.smithy.model.shapes.ServiceShape
+
+class RegionSupportTest {
+    @Test
+    fun testRegionSupportProperties() {
+        val model = """
+            namespace com.test
+
+            use aws.protocols#awsJson1_1
+            use aws.api#service
+            use aws.auth#sigv4
+
+            @service(sdkId: "service with overrides", endpointPrefix: "service-with-overrides")
+            @sigv4(name: "example")
+            @awsJson1_1
+            service Example {
+                version: "1.0.0",
+                operations: [GetFoo]
+            }
+
+            operation GetFoo {}
+        """.toSmithyModel()
+
+        val serviceShape = model.expectShape<ServiceShape>("com.test#Example")
+
+        val testCtx = model.newTestContext(serviceName = "Example")
+        val writer = KotlinWriter("com.test")
+
+        val renderingCtx = testCtx.toRenderingContext(writer, serviceShape)
+            .copy(integrations = listOf(RegionSupport()))
+
+        ServiceClientConfigGenerator(serviceShape, detectDefaultProps = false).render(renderingCtx, renderingCtx.writer)
+        val contents = writer.toString()
+
+        val expectedProps = """
+            public val region: String? = builder.region
+            public val regionProvider: RegionProvider? = builder.regionProvider
+        """.formatForTest()
+        contents.shouldContainOnlyOnceWithDiff(expectedProps)
+
+        val expectedImpl = """
+            /**
+             * The AWS region to sign with and make requests to. When specified, this static region configuration
+             * takes precedence over other region resolution methods.
+             *
+             * The region resolution order is:
+             * 1. Static region (if specified)
+             * 2. Custom region provider (if configured)
+             * 3. Default region provider chain
+             */
+            public var region: String? = null
+    
+            /**
+             * An optional region provider that determines the AWS region for client operations. When specified, this provider
+             * takes precedence over the default region provider chain, unless a static region is explicitly configured.
+             *
+             * The region resolution order is:
+             * 1. Static region (if specified)
+             * 2. Custom region provider (if configured)
+             * 3. Default region provider chain
+             */
+            public var regionProvider: RegionProvider? = null
+        """.formatForTest(indent = "        ")
+        contents.shouldContainOnlyOnceWithDiff(expectedImpl)
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
index e857f91fee..4c421f7fa7 100644
--- a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
+++ b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
@@ -8,6 +8,7 @@ import software.amazon.smithy.build.MockManifest
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.*
 import software.amazon.smithy.kotlin.codegen.core.CodegenContext
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
 import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.model.OperationNormalizer
@@ -122,9 +123,11 @@ fun Model.newTestContext(
     val manifest = MockManifest()
     val provider: SymbolProvider = KotlinCodegenPlugin.createSymbolProvider(model = this, rootNamespace = packageName, serviceName = serviceName, settings = settings)
     val service = this.getShape(ShapeId.from("$packageName#$serviceName")).get().asServiceShape().get()
-    val delegator = KotlinDelegator(settings, this, manifest, provider, integrations)
 
-    val ctx = ProtocolGenerator.GenerationContext(
+    val codegenCtx = GenerationContext(this, provider, settings, generator, integrations)
+    val delegator = KotlinDelegator(codegenCtx, manifest, integrations)
+
+    val generationCtx = ProtocolGenerator.GenerationContext(
         settings,
         this,
         service,
@@ -133,7 +136,8 @@ fun Model.newTestContext(
         generator.protocol,
         delegator,
     )
-    return TestContext(ctx, manifest, generator)
+
+    return TestContext(generationCtx, manifest, generator)
 }
 
 fun TestContext.toCodegenContext() = object : CodegenContext {
@@ -173,7 +177,7 @@ fun Model.defaultSettings(
     sdkId: String = TestModelDefault.SDK_ID,
     generateDefaultBuildFiles: Boolean = false,
     nullabilityCheckMode: CheckMode = CheckMode.CLIENT_CAREFUL,
-    defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT,
+    defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.DEFAULT,
 ): KotlinSettings {
     val serviceId = if (serviceName == null) {
         this.inferService()
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
index 4adf42b91f..012bd09c36 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
@@ -87,12 +87,12 @@ class CodegenVisitor(context: PluginContext) : ShapeVisitor.Default<Unit>() {
             integration.decorateSymbolProvider(settings, model, provider)
         }
 
-        writers = KotlinDelegator(settings, model, fileManifest, symbolProvider, integrations)
-
         protocolGenerator = resolveProtocolGenerator(integrations, model, service, settings)
-        applicationProtocol = protocolGenerator?.applicationProtocol ?: ApplicationProtocol.createDefaultHttpApplicationProtocol()
-
         baseGenerationContext = GenerationContext(model, symbolProvider, settings, protocolGenerator, integrations)
+
+        writers = KotlinDelegator(baseGenerationContext, fileManifest, integrations)
+
+        applicationProtocol = protocolGenerator?.applicationProtocol ?: ApplicationProtocol.createDefaultHttpApplicationProtocol()
     }
 
     private fun resolveProtocolGenerator(
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
index 3ee6e0633b..334285ffb3 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
@@ -5,12 +5,7 @@
 
 package software.amazon.smithy.kotlin.codegen
 
-import software.amazon.smithy.aws.traits.protocols.AwsJson1_0Trait
-import software.amazon.smithy.aws.traits.protocols.AwsJson1_1Trait
-import software.amazon.smithy.aws.traits.protocols.AwsQueryTrait
-import software.amazon.smithy.aws.traits.protocols.Ec2QueryTrait
-import software.amazon.smithy.aws.traits.protocols.RestJson1Trait
-import software.amazon.smithy.aws.traits.protocols.RestXmlTrait
+import software.amazon.smithy.aws.traits.protocols.*
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.kotlin.codegen.lang.isValidPackageName
 import software.amazon.smithy.kotlin.codegen.utils.getOrNull
@@ -24,10 +19,10 @@ import software.amazon.smithy.model.shapes.ServiceShape
 import software.amazon.smithy.model.shapes.Shape
 import software.amazon.smithy.model.shapes.ShapeId
 import software.amazon.smithy.protocol.traits.Rpcv2CborTrait
-import java.util.Optional
+import java.util.*
 import java.util.logging.Logger
+import java.util.stream.Collectors
 import kotlin.IllegalArgumentException
-import kotlin.streams.toList
 
 // shapeId of service from which to generate an SDK
 private const val SERVICE = "service"
@@ -164,7 +159,7 @@ fun Model.inferService(): ShapeId {
     val services = shapes(ServiceShape::class.java)
         .map(Shape::getId)
         .sorted()
-        .toList()
+        .collect(Collectors.toList())
 
     return when {
         services.isEmpty() -> {
@@ -273,10 +268,15 @@ enum class DefaultValueSerializationMode(val value: String) {
 
     override fun toString(): String = value
     companion object {
+        /**
+         * The default value serialization mode, which is [ALWAYS]
+         */
+        val DEFAULT = ALWAYS
+
         fun fromValue(value: String): DefaultValueSerializationMode =
-            values().find {
-                it.value == value
-            } ?: throw IllegalArgumentException("$value is not a valid DefaultValueSerializationMode, expected one of ${values().map { it.value }}")
+            requireNotNull(entries.find { it.value.equals(value, ignoreCase = true) }) {
+                "$value is not a valid DefaultValueSerializationMode, expected one of ${values().map { it.value }}"
+            }
     }
 }
 
@@ -291,7 +291,7 @@ enum class DefaultValueSerializationMode(val value: String) {
 data class ApiSettings(
     val visibility: Visibility = Visibility.PUBLIC,
     val nullabilityCheckMode: CheckMode = CheckMode.CLIENT_CAREFUL,
-    val defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT,
+    val defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.DEFAULT,
     val enableEndpointAuthProvider: Boolean = false,
     val protocolResolutionPriority: Set<ShapeId> = DEFAULT_PROTOCOL_RESOLUTION_PRIORITY,
 ) {
@@ -315,7 +315,7 @@ data class ApiSettings(
                 node.get()
                     .getStringMemberOrDefault(
                         DEFAULT_VALUE_SERIALIZATION_MODE,
-                        DefaultValueSerializationMode.WHEN_DIFFERENT.value,
+                        DefaultValueSerializationMode.DEFAULT.value,
                     ),
             )
             val enableEndpointAuthProvider = node.get().getBooleanMemberOrDefault(ENABLE_ENDPOINT_AUTH_PROVIDER, false)
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
index 2b943da042..186dcec017 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
@@ -150,6 +150,15 @@ inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.getConte
  */
 inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.getContextValue(key: SectionKey<V>): V = getContextValue(key.name)
 
+/**
+ * Convenience function to set a typed value in the context
+ * @param key
+ */
+inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.putContextValue(
+    key: SectionKey<V>,
+    value: V,
+): W = putContext(key.name, value)
+
 /**
  * Convenience function to set context only if there is no value already associated with the given [key]
  */
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
index 06d8b7497d..a3f714d741 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
@@ -8,6 +8,7 @@ package software.amazon.smithy.kotlin.codegen.core
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
+import software.amazon.smithy.kotlin.codegen.integration.SectionKey
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.Shape
@@ -16,6 +17,10 @@ import software.amazon.smithy.model.shapes.Shape
  * Common codegen properties required across different codegen contexts
  */
 interface CodegenContext {
+    companion object {
+        val Key = SectionKey<CodegenContext>("CodegenContext")
+    }
+
     val model: Model
     val symbolProvider: SymbolProvider
     val settings: KotlinSettings
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
index 9ae10da763..ea0b6459f1 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
@@ -6,11 +6,9 @@ package software.amazon.smithy.kotlin.codegen.core
 
 import software.amazon.smithy.build.FileManifest
 import software.amazon.smithy.codegen.core.*
-import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.model.SymbolProperty
 import software.amazon.smithy.kotlin.codegen.utils.namespaceToPath
-import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.Shape
 import java.nio.file.Paths
 
@@ -21,13 +19,10 @@ const val DEFAULT_TEST_SOURCE_SET_ROOT = "./src/test/kotlin/"
  * Manages writers for Kotlin files.
  */
 class KotlinDelegator(
-    private val settings: KotlinSettings,
-    private val model: Model,
+    private val ctx: CodegenContext,
     val fileManifest: FileManifest,
-    private val symbolProvider: SymbolProvider,
     private val integrations: List<KotlinIntegration> = listOf(),
 ) {
-
     private val writers: MutableMap<String, KotlinWriter> = mutableMapOf()
 
     // Tracks dependencies for source not provided by codegen that may reside in the service source tree.
@@ -91,7 +86,7 @@ class KotlinDelegator(
         shape: Shape,
         block: (KotlinWriter) -> Unit,
     ) {
-        val symbol = symbolProvider.toSymbol(shape)
+        val symbol = ctx.symbolProvider.toSymbol(shape)
         useSymbolWriter(symbol, block)
     }
 
@@ -151,7 +146,9 @@ class KotlinDelegator(
         val needsNewline = writers.containsKey(formattedFilename)
         val writer = writers.getOrPut(formattedFilename) {
             val kotlinWriter = KotlinWriter(namespace)
-            if (settings.debug) kotlinWriter.enableStackTraceComments(true)
+            kotlinWriter.putContextValue(CodegenContext.Key, ctx)
+
+            if (ctx.settings.debug) kotlinWriter.enableStackTraceComments(true)
 
             // Register all integrations [SectionWriterBindings] on the writer.
             integrations.forEach { integration ->
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
index b575efae60..f967a689e3 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
@@ -37,7 +37,7 @@ private fun getDefaultRuntimeVersion(): String {
 // publishing info
 const val RUNTIME_GROUP: String = "aws.smithy.kotlin"
 val RUNTIME_VERSION: String = System.getProperty("smithy.kotlin.codegen.clientRuntimeVersion", getDefaultRuntimeVersion())
-val KOTLIN_COMPILER_VERSION: String = System.getProperty("smithy.kotlin.codegen.kotlinCompilerVersion", "2.1.0")
+val KOTLIN_COMPILER_VERSION: String = System.getProperty("smithy.kotlin.codegen.kotlinCompilerVersion", "2.2.0")
 
 enum class SourceSet {
     CommonMain,
@@ -134,6 +134,7 @@ data class KotlinDependency(
         // External third-party dependencies
         val KOTLIN_STDLIB = KotlinDependency(GradleConfiguration.Implementation, "kotlin", "org.jetbrains.kotlin", "kotlin-stdlib", KOTLIN_COMPILER_VERSION)
         val KOTLIN_TEST = KotlinDependency(GradleConfiguration.TestImplementation, "kotlin.test", "org.jetbrains.kotlin", "kotlin-test", KOTLIN_COMPILER_VERSION)
+        val KOTLIN_TEST_IMPL = KOTLIN_TEST.copy(config = GradleConfiguration.Implementation)
     }
 
     override fun getDependencies(): List<SymbolDependency> {
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
index 1cbf3b407b..d5122a2f48 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
@@ -45,11 +45,11 @@ object RuntimeTypes {
     object HttpClient : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT) {
         val SdkHttpClient = symbol("SdkHttpClient")
 
-        object Middleware : RuntimeTypePackage(KotlinDependency.HTTP, "middleware") {
+        object Middleware : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "middleware") {
             val MutateHeadersMiddleware = symbol("MutateHeaders")
         }
 
-        object Operation : RuntimeTypePackage(KotlinDependency.HTTP, "operation") {
+        object Operation : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "operation") {
             val AuthSchemeResolver = symbol("AuthSchemeResolver")
             val context = symbol("context")
             val EndpointResolver = symbol("EndpointResolver")
@@ -68,18 +68,20 @@ object RuntimeTypes {
             val setResolvedEndpoint = symbol("setResolvedEndpoint")
         }
 
-        object Config : RuntimeTypePackage(KotlinDependency.HTTP, "config") {
+        object Config : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "config") {
             val HttpClientConfig = symbol("HttpClientConfig")
             val HttpEngineConfig = symbol("HttpEngineConfig")
+            val TimeoutConfig = symbol("TimeoutConfig")
         }
 
-        object Engine : RuntimeTypePackage(KotlinDependency.HTTP, "engine") {
+        object Engine : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "engine") {
             val HttpClientEngine = symbol("HttpClientEngine")
             val manage = symbol("manage", "engine.internal", isExtension = true)
         }
 
-        object Interceptors : RuntimeTypePackage(KotlinDependency.HTTP, "interceptors") {
+        object Interceptors : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "interceptors") {
             val ContinueInterceptor = symbol("ContinueInterceptor")
+            val DiscoveredEndpointErrorInterceptor = symbol("DiscoveredEndpointErrorInterceptor")
             val HttpInterceptor = symbol("HttpInterceptor")
             val HttpChecksumRequiredInterceptor = symbol("HttpChecksumRequiredInterceptor")
             val FlexibleChecksumsRequestInterceptor = symbol("FlexibleChecksumsRequestInterceptor")
@@ -97,7 +99,6 @@ object RuntimeTypes {
     }
 
     object Core : RuntimeTypePackage(KotlinDependency.CORE) {
-        val Clock = symbol("Clock", "time")
         val ExecutionContext = symbol("ExecutionContext", "operation")
         val ErrorMetadata = symbol("ErrorMetadata")
         val ServiceErrorMetadata = symbol("ServiceErrorMetadata")
@@ -126,11 +127,12 @@ object RuntimeTypes {
             val attributesOf = symbol("attributesOf")
             val AttributeKey = symbol("AttributeKey")
             val createOrAppend = symbol("createOrAppend")
+            val ExpiringKeyedCache = symbol("ExpiringKeyedCache")
             val get = symbol("get")
             val mutableMultiMapOf = symbol("mutableMultiMapOf")
+            val PeriodicSweepCache = symbol("PeriodicSweepCache")
             val putIfAbsent = symbol("putIfAbsent")
             val putIfAbsentNotNull = symbol("putIfAbsentNotNull")
-            val ReadThroughCache = symbol("ReadThroughCache")
             val toMutableAttributes = symbol("toMutableAttributes")
             val emptyAttributes = symbol("emptyAttributes")
         }
@@ -251,6 +253,10 @@ object RuntimeTypes {
                 val Url = symbol("Url")
             }
         }
+
+        object Region : RuntimeTypePackage(KotlinDependency.SMITHY_CLIENT, "region") {
+            val RegionProvider = symbol("RegionProvider")
+        }
     }
 
     object Serde : RuntimeTypePackage(KotlinDependency.SERDE) {
@@ -374,6 +380,7 @@ object RuntimeTypes {
             val BearerTokenAuthScheme = symbol("BearerTokenAuthScheme")
             val BearerTokenProviderConfig = symbol("BearerTokenProviderConfig")
             val BearerTokenProvider = symbol("BearerTokenProvider")
+
             val BearerToken = symbol("BearerToken")
             val EnvironmentBearerTokenProvider = symbol("EnvironmentBearerTokenProvider")
 
@@ -453,8 +460,8 @@ object RuntimeTypes {
         val RestJsonErrorDeserializer = symbol("RestJsonErrorDeserializer")
     }
     object AwsXmlProtocols : RuntimeTypePackage(KotlinDependency.AWS_XML_PROTOCOLS) {
-        val parseRestXmlErrorResponseNoSuspend = symbol("parseRestXmlErrorResponseNoSuspend")
-        val parseEc2QueryErrorResponseNoSuspend = symbol("parseEc2QueryErrorResponseNoSuspend")
+        val parseRestXmlErrorResponse = symbol("parseRestXmlErrorResponse")
+        val parseEc2QueryErrorResponse = symbol("parseEc2QueryErrorResponse")
     }
 
     object SmithyRpcV2Protocols : RuntimeTypePackage(KotlinDependency.SMITHY_RPCV2_PROTOCOLS) {
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/DocumentationPreprocessor.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/DocumentationPreprocessor.kt
index 9baf5790b9..04518e7032 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/DocumentationPreprocessor.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/DocumentationPreprocessor.kt
@@ -57,13 +57,18 @@ class DocumentationPreprocessor : KotlinIntegration {
             .applyWithin("<pre>", "</pre>", String::escapeHtml)
         val parsed = Jsoup.parse(sanitized)
 
+        fun Node.emptyOrBlank(): Boolean = when {
+            this is TextNode -> isBlank
+            else -> childNodes().all { it.emptyOrBlank() }
+        }
+
         parsed.body().filterDescendants(
             // Jsoup will preserve newlines between elements as blank text nodes. These have zero bearing on the content
             // of the document to begin with and only serve to complicate traversal.
             { it is TextNode && it.isBlank },
             // Some docs contain empty definition terms, which we render as section headers. An empty section header
             // (literal "## \n" is invalid markdown according to dokka.
-            { it.nodeName() == "dt" && it.childNodes().isEmpty() },
+            { it.nodeName() == "dt" && it.emptyOrBlank() },
         )
 
         return parsed
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
index aa308c5343..73c789e823 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
@@ -10,7 +10,6 @@ import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.core.*
 import software.amazon.smithy.kotlin.codegen.integration.SectionId
-import software.amazon.smithy.kotlin.codegen.integration.SectionKey
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.namespace
 import software.amazon.smithy.model.knowledge.TopDownIndex
@@ -31,12 +30,10 @@ object ExceptionBaseClassGenerator {
     /**
      * Defines a section in which code can be added to the body of the base exception type.
      */
-    object ExceptionBaseClassSection : SectionId {
-        val CodegenContext: SectionKey<CodegenContext> = SectionKey("CodegenContext")
-    }
+    object ExceptionBaseClassSection : SectionId
 
     fun render(ctx: CodegenContext, writer: KotlinWriter) {
-        writer.declareSection(ExceptionBaseClassSection, mapOf(ExceptionBaseClassSection.CodegenContext to ctx)) {
+        writer.declareSection(ExceptionBaseClassSection) {
             ServiceExceptionBaseClassGenerator().render(ctx, writer)
         }
     }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
index 07f7541a06..d4123f0f03 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
@@ -6,7 +6,10 @@ package software.amazon.smithy.kotlin.codegen.rendering
 
 import software.amazon.smithy.build.FileManifest
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.InlineCodeWriter
+import software.amazon.smithy.kotlin.codegen.core.InlineCodeWriterFormatter
+import software.amazon.smithy.kotlin.codegen.core.KOTLIN_COMPILER_VERSION
+import software.amazon.smithy.kotlin.codegen.core.KotlinDependency
 import software.amazon.smithy.utils.AbstractCodeWriter
 
 // Determines the jvmTarget version emitted to the build file
@@ -134,7 +137,7 @@ fun renderRootJvmPluginConfig(writer: GradleWriter) {
         """
             jvm {
                 compilations.all {
-                    kotlinOptions.jvmTarget = #S
+                    compilerOptions.jvmTarget = #S
                 }
                 testRuns["test"].executionTask.configure {
                     useJUnitPlatform()
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGenerator.kt
index 421f841f13..592b413f9a 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGenerator.kt
@@ -57,6 +57,9 @@ class ServiceClientConfigGenerator(
         add(RuntimeConfigProperty.RetryStrategy)
         add(RuntimeConfigProperty.TelemetryProvider)
 
+        add(RuntimeConfigProperty.AttemptTimeout)
+        add(RuntimeConfigProperty.CallTimeout)
+
         if (shape.hasTrait<ClientContextParamsTrait>()) {
             addAll(clientContextConfigProps(shape.expectTrait()))
         }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/StructureGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/StructureGenerator.kt
index 5d90f376d2..476050b017 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/StructureGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/StructureGenerator.kt
@@ -6,7 +6,10 @@ package software.amazon.smithy.kotlin.codegen.rendering
 
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.codegen.core.Symbol
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.RenderingContext
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.defaultName
+import software.amazon.smithy.kotlin.codegen.core.withBlock
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.model.*
 import software.amazon.smithy.kotlin.codegen.rendering.serde.ClientErrorCorrection
@@ -192,20 +195,31 @@ class StructureGenerator(
 
             for (memberShape in sortedMembers) {
                 val target = model.expectShape(memberShape.target)
-                val memberName = memberNameSymbolIndex[memberShape]!!.first
+                val (memberName, memberSymbol) = memberNameSymbolIndex.getValue(memberShape)
                 if (target is BlobShape && !target.hasTrait<StreamingTrait>()) {
-                    openBlock("if (#1L != null) {", memberName)
-                        .write("if (other.#1L == null) return false", memberName)
-                        .write("if (!#1L.contentEquals(other.#1L)) return false", memberName)
-                        .closeBlock("} else if (other.#1L != null) return false", memberName)
+                    if (memberSymbol.isNullable) {
+                        openBlock("if (#1L != null) {", memberName)
+                            .write("if (other.#1L == null) return false", memberName)
+                            .write("if (!#1L.contentEquals(other.#1L)) return false", memberName)
+                            .closeBlock("} else if (other.#1L != null) return false", memberName)
+                    } else {
+                        write("if (!#1L.contentEquals(other.#1L)) return false", memberName)
+                    }
                 } else if (target is ListShape && target.member.targetOrSelf(model).isBlobShape) {
-                    openBlock("if (#L != null) {", memberName)
-                        .write("if (other.#L == null) return false", memberName)
-                        .write("if (#1L.size != other.#1L.size) return false", memberName)
-                        .openBlock("for (i in #L.indices) {", memberName)
-                        .write("if (!#1L[i].contentEquals(other.#1L[i])) return false", memberName)
-                        .closeBlock("}")
-                        .closeBlock("} else if (other.#1L != null) return false", memberName)
+                    if (memberSymbol.isNullable) {
+                        openBlock("if (#L != null) {", memberName)
+                            .write("if (other.#L == null) return false", memberName)
+                            .write("if (#1L.size != other.#1L.size) return false", memberName)
+                            .openBlock("for (i in #L.indices) {", memberName)
+                            .write("if (!#1L[i].contentEquals(other.#1L[i])) return false", memberName)
+                            .closeBlock("}")
+                            .closeBlock("} else if (other.#1L != null) return false", memberName)
+                    } else {
+                        write("if (#1L.size != other.#1L.size) return false", memberName)
+                            .openBlock("for (i in #L.indices) {", memberName)
+                            .write("if (!#1L[i].contentEquals(other.#1L[i])) return false", memberName)
+                            .closeBlock("}")
+                    }
                 } else if (target is DoubleShape || target is FloatShape) {
                     // NaNs must be compared using .equals()
                     write("if (!(#1L?.equals(other.#1L) ?: (other.#1L == null))) return false", memberName)
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
similarity index 55%
rename from codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt
rename to codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
index 73b6e434da..2d21de0577 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
@@ -12,12 +12,11 @@ import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.expectShape
 import software.amazon.smithy.kotlin.codegen.model.expectTrait
-import software.amazon.smithy.kotlin.codegen.rendering.endpoints.EndpointResolverAdapterGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.endpoints.SdkEndpointBuiltinIntegration
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ServiceShape
 
-class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
+class DefaultEndpointDiscovererGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
     private val symbol = symbolFor(ctx.settings)
     private val service = ctx.model.expectShape<ServiceShape>(ctx.settings.service)
     private val clientSymbol = ctx.symbolProvider.toSymbol(service)
@@ -30,58 +29,47 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
     companion object {
         fun symbolFor(settings: KotlinSettings): Symbol = buildSymbol {
             val clientName = clientName(settings.sdkId)
-            name = "${clientName}EndpointDiscoverer"
+            name = "Default${clientName}EndpointDiscoverer"
             namespace = "${settings.pkg.name}.endpoints"
         }
     }
 
     fun render() {
         delegator.applyFileWriter(symbol) {
+            val service = clientName(ctx.settings.sdkId)
             dokka(
                 """
-                    A class which looks up specific endpoints for ${ctx.settings.sdkId} calls via the `$operationName`
-                    API. These unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent
-                    calls.
+                    A class which looks up specific endpoints for $service calls via the `$operationName` API. These
+                    unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent calls.
+                    @param cache An [ExpiringKeyedCache] implementation used to cache discovered hosts
                 """.trimIndent(),
             )
+
             withBlock(
-                "#L class #T {",
+                "#1L class #2T(#1L val cache: #3T<DiscoveryParams, #4T> = #5T(10.#6T)) : #7T {",
                 "}",
                 ctx.settings.api.visibility,
                 symbol,
+                RuntimeTypes.Core.Collections.ExpiringKeyedCache,
+                RuntimeTypes.Core.Net.Host,
+                RuntimeTypes.Core.Collections.PeriodicSweepCache,
+                KotlinTypes.Time.minutes,
+                EndpointDiscovererInterfaceGenerator.symbolFor(ctx.settings),
             ) {
-                write(
-                    "private val cache = #T<DiscoveryParams, #T>(10.#T, #T.System)",
-                    RuntimeTypes.Core.Collections.ReadThroughCache,
-                    RuntimeTypes.Core.Net.Host,
-                    KotlinTypes.Time.minutes,
-                    RuntimeTypes.Core.Clock,
-                )
-                write("")
                 renderAsEndpointResolver()
                 write("")
-                renderDiscoverHost()
-                write("")
                 renderInvalidate()
             }
-            write("")
-            write(
-                """private val discoveryParamsKey = #T<DiscoveryParams>("DiscoveryParams")""",
-                RuntimeTypes.Core.Collections.AttributeKey,
-            )
-            write("private data class DiscoveryParams(private val region: String?, private val identity: String)")
         }
     }
 
     private fun KotlinWriter.renderAsEndpointResolver() {
         withBlock(
-            "internal fun asEndpointResolver(client: #T, delegate: #T) = #T { request ->",
+            "override fun asEndpointResolver(client: #1T, delegate: #2T): #2T = #2T { request ->",
             "}",
             clientSymbol,
-            EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             RuntimeTypes.HttpClient.Operation.EndpointResolver,
         ) {
-            // Backported from https://github.com/smithy-lang/smithy-kotlin/pull/1221; replace when merging v1.5 to main
             withBlock("if (client.config.#L == null) {", "}", SdkEndpointBuiltinIntegration.EndpointUrlProp.propertyName) {
                 write("val identity = request.identity")
                 write(
@@ -90,7 +78,7 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
                 )
                 write("")
                 write("val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)")
-                write("request.context[discoveryParamsKey] = cacheKey")
+                write("request.context[DiscoveryParamsKey] = cacheKey")
                 write("val discoveredHost = cache.get(cacheKey) { discoverHost(client) }")
                 write("")
                 write("val originalEndpoint = delegate.resolve(request)")
@@ -99,6 +87,7 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
                     write("originalEndpoint.headers,")
                     write("originalEndpoint.attributes,")
                 }
+
                 // If user manually specifies endpointUrl, skip endpoint discovery
                 closeAndOpenBlock("} else {")
                 write("delegate.resolve(request)")
@@ -106,34 +95,9 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
         }
     }
 
-    private fun KotlinWriter.renderDiscoverHost() {
-        openBlock(
-            "private suspend fun discoverHost(client: #T): #T<#T> =",
-            clientSymbol,
-            RuntimeTypes.Core.Utils.ExpiringValue,
-            RuntimeTypes.Core.Net.Host,
-        )
-        // ASSUMPTION No services which use discovery include parameters to the EP operation (despite being
-        // possible according to the Smithy spec).
-        write("client.#L()", operationName)
-        indent()
-        write(".endpoints")
-        withBlock("?.map { ep -> #T(", ")}", RuntimeTypes.Core.Utils.ExpiringValue) {
-            write("#T.parse(ep.address!!),", RuntimeTypes.Core.Net.Host)
-            write("#T.now() + ep.cachePeriodInMinutes.#T,", RuntimeTypes.Core.Instant, KotlinTypes.Time.minutes)
-        }
-        write("?.firstOrNull()")
-        write(
-            """?: throw #T("Unable to discover any endpoints when invoking #L!")""",
-            RuntimeTypes.SmithyClient.Endpoints.EndpointProviderException,
-            operationName,
-        )
-        dedent(2)
-    }
-
     private fun KotlinWriter.renderInvalidate() {
-        withBlock("internal suspend fun invalidate(context: #T) {", "}", RuntimeTypes.Core.ExecutionContext) {
-            write("context.getOrNull(discoveryParamsKey)?.let { cache.invalidate(it) }")
+        withBlock("override public suspend fun invalidate(context: #T) {", "}", RuntimeTypes.Core.ExecutionContext) {
+            write("context.getOrNull(DiscoveryParamsKey)?.let { cache.invalidate(it) }")
         }
     }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt
new file mode 100644
index 0000000000..ddc70752db
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt
@@ -0,0 +1,94 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import software.amazon.smithy.aws.traits.clientendpointdiscovery.ClientEndpointDiscoveryTrait
+import software.amazon.smithy.codegen.core.Symbol
+import software.amazon.smithy.kotlin.codegen.KotlinSettings
+import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+import software.amazon.smithy.kotlin.codegen.model.expectShape
+import software.amazon.smithy.kotlin.codegen.model.expectTrait
+import software.amazon.smithy.model.shapes.OperationShape
+import software.amazon.smithy.model.shapes.ServiceShape
+
+class EndpointDiscovererInterfaceGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
+    private val symbol = symbolFor(ctx.settings)
+    private val service = ctx.model.expectShape<ServiceShape>(ctx.settings.service)
+    private val clientSymbol = ctx.symbolProvider.toSymbol(service)
+    private val operationName = run {
+        val epDiscoveryTrait = service.expectTrait<ClientEndpointDiscoveryTrait>()
+        val operation = ctx.model.expectShape<OperationShape>(epDiscoveryTrait.operation)
+        operation.defaultName()
+    }
+
+    companion object {
+        fun symbolFor(settings: KotlinSettings): Symbol = buildSymbol {
+            val clientName = clientName(settings.sdkId)
+            name = "${clientName}EndpointDiscoverer"
+            namespace = "${settings.pkg.name}.endpoints"
+        }
+    }
+
+    fun render() {
+        delegator.applyFileWriter(symbol) {
+            dokka("Represents the logic for automatically discovering endpoints for ${ctx.settings.sdkId} calls")
+            withBlock(
+                "#L interface #T {",
+                "}",
+                ctx.settings.api.visibility,
+                symbol,
+            ) {
+                write(
+                    "#1L fun asEndpointResolver(client: #2T, delegate: #3T): #3T",
+                    ctx.settings.api.visibility,
+                    clientSymbol,
+                    RuntimeTypes.HttpClient.Operation.EndpointResolver,
+                )
+                write("")
+                renderDiscoverHost()
+                write("")
+                write("public suspend fun invalidate(context: #T)", RuntimeTypes.Core.ExecutionContext)
+            }
+            write("")
+            write(
+                "#L data class DiscoveryParams(private val region: String?, private val identity: String)",
+                ctx.settings.api.visibility,
+            )
+            write(
+                """#1L val DiscoveryParamsKey: #2T<DiscoveryParams> = #2T("DiscoveryParams")""",
+                ctx.settings.api.visibility,
+                RuntimeTypes.Core.Collections.AttributeKey,
+            )
+        }
+    }
+
+    private fun KotlinWriter.renderDiscoverHost() {
+        openBlock(
+            "#L suspend fun discoverHost(client: #T): #T<#T> =",
+            ctx.settings.api.visibility,
+            clientSymbol,
+            RuntimeTypes.Core.Utils.ExpiringValue,
+            RuntimeTypes.Core.Net.Host,
+        )
+        // ASSUMPTION No services which use discovery include parameters to the EP operation (despite being
+        // possible according to the Smithy spec).
+        write("client.#L()", operationName)
+        indent()
+        write(".endpoints")
+        withBlock("?.map { ep -> #T(", ")}", RuntimeTypes.Core.Utils.ExpiringValue) {
+            write("#T.parse(ep.address!!),", RuntimeTypes.Core.Net.Host)
+            write("#T.now() + ep.cachePeriodInMinutes.#T,", RuntimeTypes.Core.Instant, KotlinTypes.Time.minutes)
+        }
+        write("?.firstOrNull()")
+        write(
+            """?: throw #T("Unable to discover any endpoints when invoking #L!")""",
+            RuntimeTypes.SmithyClient.Endpoints.EndpointProviderException,
+            operationName,
+        )
+        dedent(2)
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
index 62906af4d7..4e8a7446a1 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
@@ -22,26 +22,38 @@ import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ServiceShape
 
 class EndpointDiscoveryIntegration : KotlinIntegration {
-    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> {
-        val endpointDiscoveryOptional = ctx
+    companion object {
+        const val CLIENT_CONFIG_NAME = "endpointDiscoverer"
+        const val ORDER: Byte = 0 // doesn't depend on any other integrations
+
+        fun isEnabledFor(model: Model, settings: KotlinSettings) = model
+            .expectShape<ServiceShape>(settings.service)
+            .hasTrait<ClientEndpointDiscoveryTrait>()
+
+        fun isOptionalFor(ctx: CodegenContext) = ctx
             .model
             .operationShapes
             .none { it.getTrait<ClientDiscoveredEndpointTrait>()?.isRequired == true }
-        val discovererSymbol = EndpointDiscovererGenerator.symbolFor(ctx.settings)
+    }
+
+    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> {
+        val endpointDiscoveryOptional = isOptionalFor(ctx)
+        val interfaceSymbol = EndpointDiscovererInterfaceGenerator.symbolFor(ctx.settings)
         return super.additionalServiceConfigProps(ctx) + listOf(
             ConfigProperty {
-                name = "endpointDiscoverer"
+                name = CLIENT_CONFIG_NAME
 
                 if (endpointDiscoveryOptional) {
                     documentation = """
-                        The endpoint discoverer for this client, if applicable. By default, no endpoint
-                        discovery is provided. To use endpoint discovery, set this to a valid
-                        [${discovererSymbol.name}] instance.
+                        The endpoint discoverer for this client, if applicable. By default, no endpoint discovery is
+                        provided. To use endpoint discovery, set this to a valid [${interfaceSymbol.name}] instance.
                     """.trimIndent()
-                    symbol = discovererSymbol.asNullable()
+                    symbol = interfaceSymbol.asNullable()
                 } else {
+                    val defaultImplSymbol = DefaultEndpointDiscovererGenerator.symbolFor(ctx.settings)
                     documentation = "The endpoint discoverer for this client"
-                    useSymbolWithNullableBuilder(discovererSymbol, "${discovererSymbol.name}()")
+                    additionalImports = listOf(defaultImplSymbol)
+                    useSymbolWithNullableBuilder(interfaceSymbol, "${defaultImplSymbol.name}()")
                 }
             },
         )
@@ -50,10 +62,11 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
     override fun customizeMiddleware(
         ctx: ProtocolGenerator.GenerationContext,
         resolved: List<ProtocolMiddleware>,
-    ): List<ProtocolMiddleware> = super.customizeMiddleware(ctx, resolved) + listOf(DiscoveredEndpointMiddleware)
+    ): List<ProtocolMiddleware> = resolved + DiscoveredEndpointErrorMiddleware
 
-    override fun enabledForService(model: Model, settings: KotlinSettings): Boolean =
-        model.expectShape<ServiceShape>(settings.service).hasTrait<ClientEndpointDiscoveryTrait>()
+    override fun enabledForService(model: Model, settings: KotlinSettings): Boolean = isEnabledFor(model, settings)
+
+    override val order = ORDER
 
     override val sectionWriters: List<SectionWriterBinding> = listOf(
         SectionWriterBinding(HttpProtocolClientGenerator.EndpointResolverAdapterBinding, ::renderEndpointResolver),
@@ -69,13 +82,15 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
             null -> writer.write("#L", previousValue)
 
             true -> writer.write(
-                "execution.endpointResolver = config.endpointDiscoverer.asEndpointResolver(this@#L, #T(config))",
+                "execution.endpointResolver = config.#L.asEndpointResolver(this@#L, #T(config))",
+                CLIENT_CONFIG_NAME,
                 defaultClientName,
                 EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             )
 
             false -> writer.write(
-                "execution.endpointResolver = config.endpointDiscoverer?.asEndpointResolver(this@#1L, #2T(config)) ?: #2T(config)",
+                "execution.endpointResolver = config.#1L?.asEndpointResolver(this@#2L, #3T(config)) ?: #3T(config)",
+                CLIENT_CONFIG_NAME,
                 defaultClientName,
                 EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             )
@@ -83,30 +98,29 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
     }
 
     override fun writeAdditionalFiles(ctx: CodegenContext, delegator: KotlinDelegator) {
-        EndpointDiscovererGenerator(ctx, delegator).render()
-        super.writeAdditionalFiles(ctx, delegator)
+        EndpointDiscovererInterfaceGenerator(ctx, delegator).render()
+
+        if (!isOptionalFor(ctx)) {
+            DefaultEndpointDiscovererGenerator(ctx, delegator).render()
+        }
     }
 }
 
-private object DiscoveredEndpointMiddleware : ProtocolMiddleware {
-    override val name: String = "DiscoveredEndpointMiddleware"
+private object DiscoveredEndpointErrorMiddleware : ProtocolMiddleware {
+    override val name: String = "DiscoveredEndpointErrorMiddleware"
 
     override fun isEnabledFor(ctx: ProtocolGenerator.GenerationContext, op: OperationShape): Boolean =
-        op.getTrait<ClientEndpointDiscoveryTrait>()?.optionalError?.getOrNull() != null &&
+        ctx.service.getTrait<ClientEndpointDiscoveryTrait>()?.optionalError?.getOrNull() != null &&
             op.hasTrait<ClientDiscoveredEndpointTrait>()
 
     override fun render(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, writer: KotlinWriter) {
-        val interceptor = buildSymbol {
-            name = "DiscoveredEndpointErrorInterceptor"
-            namespace(KotlinDependency.HTTP_CLIENT, "aws.smithy.kotlin.runtime.http.interceptors")
-        }
-
         val errorShapeId = ctx.service.expectTrait<ClientEndpointDiscoveryTrait>().optionalError.get()
         val errorShape = ctx.model.expectShape(errorShapeId)
         val errorSymbol = ctx.symbolProvider.toSymbol(errorShape)
         writer.write(
-            "config.endpointDiscoverer?.let { op.interceptors.add(#T(#T, it::invalidate)) }",
-            interceptor,
+            "config.#L?.let { op.interceptors.add(#T(#T::class, it::invalidate)) }",
+            EndpointDiscoveryIntegration.CLIENT_CONFIG_NAME,
+            RuntimeTypes.HttpClient.Interceptors.DiscoveredEndpointErrorInterceptor,
             errorSymbol,
         )
     }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpProtocolClientGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpProtocolClientGenerator.kt
index f12ab07a26..0b7c3f7e0a 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpProtocolClientGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpProtocolClientGenerator.kt
@@ -9,8 +9,11 @@ import software.amazon.smithy.kotlin.codegen.core.*
 import software.amazon.smithy.kotlin.codegen.integration.SectionId
 import software.amazon.smithy.kotlin.codegen.integration.SectionKey
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
-import software.amazon.smithy.kotlin.codegen.model.*
+import software.amazon.smithy.kotlin.codegen.model.getTrait
+import software.amazon.smithy.kotlin.codegen.model.hasIdempotentTokenMember
+import software.amazon.smithy.kotlin.codegen.model.hasStreamingMember
 import software.amazon.smithy.kotlin.codegen.model.knowledge.AuthIndex
+import software.amazon.smithy.kotlin.codegen.model.operationSignature
 import software.amazon.smithy.kotlin.codegen.rendering.auth.AuthSchemeProviderAdapterGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.auth.IdentityProviderConfigGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.endpoints.EndpointResolverAdapterGenerator
@@ -342,6 +345,8 @@ open class HttpProtocolClientGenerator(
             "}",
             RuntimeTypes.Core.ExecutionContext,
         ) {
+            putIfAbsent(RuntimeTypes.HttpClient.Operation.HttpOperationContext, "AttemptTimeout", nullable = true)
+            putIfAbsent(RuntimeTypes.HttpClient.Operation.HttpOperationContext, "CallTimeout", nullable = true)
             putIfAbsent(RuntimeTypes.SmithyClient.SdkClientOption, "ClientName")
             putIfAbsent(RuntimeTypes.SmithyClient.SdkClientOption, "LogMode")
             if (ctx.service.hasIdempotentTokenMember(ctx.model)) {
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/util/RuntimeConfigProperty.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/util/RuntimeConfigProperty.kt
index 0108838d9c..36dbb1c671 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/util/RuntimeConfigProperty.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/util/RuntimeConfigProperty.kt
@@ -10,6 +10,7 @@ import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.codegen.core.SymbolReference
 import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
+import software.amazon.smithy.kotlin.codegen.model.asNullable
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 
 /**
@@ -185,6 +186,31 @@ object RuntimeConfigProperty {
             The ordered preference of [AuthScheme] that this client will use. 
         """.trimIndent()
     }
+
+    val AttemptTimeout = ConfigProperty {
+        name = "attemptTimeout"
+        symbol = KotlinTypes.Time.Duration.asNullable()
+        baseClass = RuntimeTypes.HttpClient.Config.TimeoutConfig
+        useNestedBuilderBaseClass()
+
+        documentation = """
+            The maximum amount of time to wait for any single attempt of a request within the retry loop. By default,
+            the value is `null` indicating no timeout is enforced. Attempt timeouts may be retried if allowed by the
+            current retry policy and retry capacity.
+        """.trimIndent()
+    }
+
+    val CallTimeout = ConfigProperty {
+        name = "callTimeout"
+        symbol = KotlinTypes.Time.Duration.asNullable()
+        baseClass = RuntimeTypes.HttpClient.Config.TimeoutConfig
+        useNestedBuilderBaseClass()
+
+        documentation = """
+            The maximum amount of time to wait for completion of a call, including any retries after the first attempt.
+            By default, the value is `null` indicating no timeout is enforced. Call timeouts are not retried.
+        """.trimIndent()
+    }
 }
 
 internal val Symbol.nestedBuilder: Symbol
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
index 2de132c9fa..7910b25cc1 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
@@ -11,6 +11,7 @@ import org.junit.jupiter.params.provider.Arguments
 import org.junit.jupiter.params.provider.ArgumentsProvider
 import org.junit.jupiter.params.provider.ArgumentsSource
 import org.junit.jupiter.params.provider.CsvSource
+import org.junit.jupiter.params.support.ParameterDeclarations
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.kotlin.codegen.test.TestModelDefault
 import software.amazon.smithy.kotlin.codegen.test.toSmithyModel
@@ -392,7 +393,10 @@ class TestProtocolSelectionArgumentProvider : ArgumentsProvider {
         private const val NO_CBOR = "awsJson1_0, awsJson1_1, restJson1, restXml, awsQuery, ec2Query"
     }
 
-    override fun provideArguments(context: ExtensionContext?): Stream<out Arguments> = Stream.of(
+    override fun provideArguments(
+        parameters: ParameterDeclarations?,
+        context: ExtensionContext?,
+    ): Stream<out Arguments> = Stream.of(
         Arguments.of(
             ALL_PROTOCOLS,
             "rpcv2Cbor, awsJson1_0",
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
index 162f32ac92..a5fb28e902 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
@@ -97,7 +97,9 @@ class KotlinDelegatorTest {
             Node.parse(configContents).expectObjectNode(),
         )
         val manifest = MockManifest()
-        val delegator = KotlinDelegator(settings, model, manifest, KotlinSymbolProvider(model, settings))
+        val symbolProvider = KotlinSymbolProvider(model, settings)
+        val ctx = GenerationContext(model, symbolProvider, settings, protocolGenerator = null)
+        val delegator = KotlinDelegator(ctx, manifest)
 
         val generatedSymbol = buildSymbol {
             name = "Foo"
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
index a2272852fe..6356d3fbf6 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
@@ -241,7 +241,7 @@ class ExceptionGeneratorTest {
                     get() = listOf(SectionWriterBinding(ExceptionBaseClassGenerator.ExceptionBaseClassSection, exceptionSectionWriter))
 
                 private val exceptionSectionWriter = SectionWriter { writer, _ ->
-                    val ctx = writer.getContextValue(ExceptionBaseClassGenerator.ExceptionBaseClassSection.CodegenContext)
+                    val ctx = writer.getContextValue(CodegenContext.Key)
                     ServiceExceptionBaseClassGenerator(exceptionBaseClassSymbol).render(ctx, writer)
                 }
             }
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGeneratorTest.kt
index 7f1521ee02..cb73290a86 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ServiceClientConfigGeneratorTest.kt
@@ -8,7 +8,10 @@ package software.amazon.smithy.kotlin.codegen.rendering
 import io.kotest.matchers.shouldBe
 import io.kotest.matchers.string.shouldContain
 import software.amazon.smithy.codegen.core.SymbolReference
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.CodegenContext
+import software.amazon.smithy.kotlin.codegen.core.KotlinDependency
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.loadModelFromResource
@@ -42,14 +45,16 @@ class ServiceClientConfigGeneratorTest {
         contents.assertBalancedBracesAndParens()
 
         val expectedCtor = """
-public class Config private constructor(builder: Builder) : HttpAuthConfig, HttpClientConfig, HttpEngineConfig by builder.buildHttpEngineConfig(), IdempotencyTokenConfig, RetryClientConfig, RetryStrategyClientConfig by builder.buildRetryStrategyClientConfig(), SdkClientConfig, TelemetryConfig {
+public class Config private constructor(builder: Builder) : HttpAuthConfig, HttpClientConfig, HttpEngineConfig by builder.buildHttpEngineConfig(), IdempotencyTokenConfig, RetryClientConfig, RetryStrategyClientConfig by builder.buildRetryStrategyClientConfig(), SdkClientConfig, TelemetryConfig, TimeoutConfig {
 """
         contents.shouldContainWithDiff(expectedCtor)
 
         val expectedProps = """
     override val clientName: String = builder.clientName
+    override val attemptTimeout: Duration? = builder.attemptTimeout
     override val authSchemePreference: kotlin.collections.List<aws.smithy.kotlin.runtime.auth.AuthSchemeId>? = builder.authSchemePreference
     override val authSchemes: kotlin.collections.List<aws.smithy.kotlin.runtime.http.auth.AuthScheme> = builder.authSchemes
+    override val callTimeout: Duration? = builder.callTimeout
     public val endpointProvider: TestEndpointProvider = requireNotNull(builder.endpointProvider) { "endpointProvider is a required configuration property" }
     override val idempotencyTokenProvider: IdempotencyTokenProvider = builder.idempotencyTokenProvider ?: IdempotencyTokenProvider.Default
     override val interceptors: kotlin.collections.List<aws.smithy.kotlin.runtime.http.interceptors.HttpInterceptor> = builder.interceptors
@@ -60,12 +65,19 @@ public class Config private constructor(builder: Builder) : HttpAuthConfig, Http
         contents.shouldContainWithDiff(expectedProps)
 
         val expectedBuilder = """
-    public class Builder : HttpAuthConfig.Builder, HttpClientConfig.Builder, HttpEngineConfig.Builder by HttpEngineConfigImpl.BuilderImpl(), IdempotencyTokenConfig.Builder, RetryClientConfig.Builder, RetryStrategyClientConfig.Builder by RetryStrategyClientConfigImpl.BuilderImpl(), SdkClientConfig.Builder<Config>, TelemetryConfig.Builder {
+    public class Builder : HttpAuthConfig.Builder, HttpClientConfig.Builder, HttpEngineConfig.Builder by HttpEngineConfigImpl.BuilderImpl(), IdempotencyTokenConfig.Builder, RetryClientConfig.Builder, RetryStrategyClientConfig.Builder by RetryStrategyClientConfigImpl.BuilderImpl(), SdkClientConfig.Builder<Config>, TelemetryConfig.Builder, TimeoutConfig.Builder {
         /**
          * A reader-friendly name for the client.
          */
         override var clientName: String = "Test"
 
+        /**
+         * The maximum amount of time to wait for any single attempt of a request within the retry loop. By default,
+         * the value is `null` indicating no timeout is enforced. Attempt timeouts may be retried if allowed by the
+         * current retry policy and retry capacity.
+         */
+        override var attemptTimeout: Duration? = null
+
         /**
          * The ordered preference of [AuthScheme] that this client will use.
          */
@@ -79,6 +91,12 @@ public class Config private constructor(builder: Builder) : HttpAuthConfig, Http
          */
         override var authSchemes: kotlin.collections.List<aws.smithy.kotlin.runtime.http.auth.AuthScheme> = emptyList()
 
+        /**
+         * The maximum amount of time to wait for completion of a call, including any retries after the first attempt.
+         * By default, the value is `null` indicating no timeout is enforced. Call timeouts are not retried.
+         */
+        override var callTimeout: Duration? = null
+
         /**
          * The endpoint provider used to determine where to make service requests. **This is an advanced config
          * option.**
@@ -245,8 +263,10 @@ public class Config private constructor(builder: Builder) {
         // Expect logMode config value to override default to LogMode.Request
         val expectedConfigValues = """
     override val clientName: String = builder.clientName
+    override val attemptTimeout: Duration? = builder.attemptTimeout
     override val authSchemePreference: kotlin.collections.List<aws.smithy.kotlin.runtime.auth.AuthSchemeId>? = builder.authSchemePreference
     override val authSchemes: kotlin.collections.List<aws.smithy.kotlin.runtime.http.auth.AuthScheme> = builder.authSchemes
+    override val callTimeout: Duration? = builder.callTimeout
     public val customProp: Int? = builder.customProp
     public val endpointProvider: TestEndpointProvider = requireNotNull(builder.endpointProvider) { "endpointProvider is a required configuration property" }
     override val idempotencyTokenProvider: IdempotencyTokenProvider = builder.idempotencyTokenProvider ?: IdempotencyTokenProvider.Default
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt
new file mode 100644
index 0000000000..d5e0a6e152
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt
@@ -0,0 +1,78 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.build.MockManifest
+import software.amazon.smithy.kotlin.codegen.test.formatForTest
+import software.amazon.smithy.kotlin.codegen.test.newTestContext
+import software.amazon.smithy.kotlin.codegen.test.shouldContainOnlyOnceWithDiff
+import software.amazon.smithy.kotlin.codegen.test.toCodegenContext
+
+class DefaultEndpointDiscovererGeneratorTest {
+    private val renderedCodegen: String = run {
+        val model = model()
+        val testCtx = model.newTestContext()
+        val delegator = testCtx.generationCtx.delegator
+        val generator = DefaultEndpointDiscovererGenerator(testCtx.toCodegenContext(), delegator)
+        generator.render()
+
+        delegator.flushWriters()
+        val testManifest = delegator.fileManifest as MockManifest
+        testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/DefaultTestEndpointDiscoverer.kt")
+    }
+
+    @Test
+    fun testClass() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                /**
+                 * A class which looks up specific endpoints for Test calls via the `getEndpoints` API. These
+                 * unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent calls.
+                 * @param cache An [ExpiringKeyedCache] implementation used to cache discovered hosts
+                 */
+                public class DefaultTestEndpointDiscoverer(public val cache: ExpiringKeyedCache<DiscoveryParams, Host> = PeriodicSweepCache(10.minutes)) : TestEndpointDiscoverer {
+            """.trimIndent(),
+        )
+    }
+
+    @Test
+    fun testAsEndpointResolver() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                override fun asEndpointResolver(client: TestClient, delegate: EndpointResolver): EndpointResolver = EndpointResolver { request ->
+                    if (client.config.endpointUrl == null) {
+                        val identity = request.identity
+                        require(identity is Credentials) { "Endpoint discovery requires AWS credentials" }
+                
+                        val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)
+                        request.context[DiscoveryParamsKey] = cacheKey
+                        val discoveredHost = cache.get(cacheKey) { discoverHost(client) }
+                
+                        val originalEndpoint = delegate.resolve(request)
+                        Endpoint(
+                            originalEndpoint.uri.copy { host = discoveredHost },
+                            originalEndpoint.headers,
+                            originalEndpoint.attributes,
+                        )
+                    } else {
+                        delegate.resolve(request)
+                    }
+                }
+            """.formatForTest(),
+        )
+    }
+
+    @Test
+    fun testInvalidate() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                override public suspend fun invalidate(context: ExecutionContext) {
+                    context.getOrNull(DiscoveryParamsKey)?.let { cache.invalidate(it) }
+                }
+            """.formatForTest(),
+        )
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt
deleted file mode 100644
index 37b9e6a900..0000000000
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
-
-import org.junit.jupiter.api.Test
-import software.amazon.smithy.build.MockManifest
-import software.amazon.smithy.kotlin.codegen.test.*
-
-class EndpointDiscovererGeneratorTest {
-    @Test
-    fun testClass() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-            public class TestEndpointDiscoverer {
-                private val cache = ReadThroughCache<DiscoveryParams, Host>(10.minutes, Clock.System)
-            """.trimIndent(),
-        )
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                }
-                
-                private val discoveryParamsKey = AttributeKey<DiscoveryParams>("DiscoveryParams")
-                private data class DiscoveryParams(private val region: String?, private val identity: String)
-            """.trimIndent(),
-        )
-    }
-
-    @Test
-    fun testAsEndpointResolver() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                internal fun asEndpointResolver(client: TestClient, delegate: EndpointResolverAdapter) = EndpointResolver { request ->
-                    if (client.config.endpointUrl == null) {
-                        val identity = request.identity
-                        require(identity is Credentials) { "Endpoint discovery requires AWS credentials" }
-                
-                        val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)
-                        request.context[discoveryParamsKey] = cacheKey
-                        val discoveredHost = cache.get(cacheKey) { discoverHost(client) }
-                
-                        val originalEndpoint = delegate.resolve(request)
-                        Endpoint(
-                            originalEndpoint.uri.copy { host = discoveredHost },
-                            originalEndpoint.headers,
-                            originalEndpoint.attributes,
-                        )
-                    } else {
-                        delegate.resolve(request)
-                    }
-                }
-            """.formatForTest(),
-        )
-    }
-
-    @Test
-    fun testDiscoverHost() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                private suspend fun discoverHost(client: TestClient): ExpiringValue<Host> =
-                    client.getEndpoints()
-                        .endpoints
-                        ?.map { ep -> ExpiringValue(
-                            Host.parse(ep.address!!),
-                            Instant.now() + ep.cachePeriodInMinutes.minutes,
-                        )}
-                        ?.firstOrNull()
-                        ?: throw EndpointProviderException("Unable to discover any endpoints when invoking getEndpoints!")
-            """.formatForTest(),
-        )
-    }
-
-    @Test
-    fun testInvalidate() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                internal suspend fun invalidate(context: ExecutionContext) {
-                    context.getOrNull(discoveryParamsKey)?.let { cache.invalidate(it) }
-                }
-            """.formatForTest(),
-        )
-    }
-
-    private fun render(): String {
-        val model = model()
-        val testCtx = model.newTestContext()
-        val delegator = testCtx.generationCtx.delegator
-        val generator = EndpointDiscovererGenerator(testCtx.toCodegenContext(), delegator)
-        generator.render()
-
-        delegator.flushWriters()
-        val testManifest = delegator.fileManifest as MockManifest
-        return testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/TestEndpointDiscoverer.kt")
-    }
-
-    private fun model() =
-        """
-            namespace com.test
-
-            use aws.protocols#awsJson1_1
-            use aws.api#service
-            use aws.auth#sigv4
-
-            @service(sdkId: "test")
-            @sigv4(name: "test")
-            @awsJson1_1
-            @aws.api#clientEndpointDiscovery(
-                operation: GetEndpoints,
-                error: BadEndpointError
-            )
-            service Test {
-                version: "1.0.0",
-                operations: [GetEndpoints]
-            }
-            
-            @error("client")
-            @httpError(421)
-            structure BadEndpointError { }
-
-            @http(method: "GET", uri: "/endpoints")
-            operation GetEndpoints {
-                input: GetEndpointsInput
-                output: GetEndpointsOutput
-            }
-            
-            @input
-            structure GetEndpointsInput { }
-            
-            @output
-            structure GetEndpointsOutput {
-                Endpoints: Endpoints
-            }
-            
-            list Endpoints {
-                member: Endpoint
-            }
-            
-            structure Endpoint {
-                Address: String
-                CachePeriodInMinutes: Long
-            }
-        """.toSmithyModel()
-}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt
new file mode 100644
index 0000000000..998fc8e577
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt
@@ -0,0 +1,75 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.build.MockManifest
+import software.amazon.smithy.kotlin.codegen.test.formatForTest
+import software.amazon.smithy.kotlin.codegen.test.newTestContext
+import software.amazon.smithy.kotlin.codegen.test.shouldContainOnlyOnceWithDiff
+import software.amazon.smithy.kotlin.codegen.test.toCodegenContext
+
+class EndpointDiscovererInterfaceGeneratorTest {
+    @Test
+    fun testInterface() {
+        val actual = render()
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                /**
+                 * Represents the logic for automatically discovering endpoints for Test calls
+                 */
+                public interface TestEndpointDiscoverer {
+                    public fun asEndpointResolver(client: TestClient, delegate: EndpointResolver): EndpointResolver
+            """.trimIndent(),
+        )
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                public suspend fun invalidate(context: ExecutionContext)
+            """.trimIndent(),
+        )
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                }
+                
+                public data class DiscoveryParams(private val region: String?, private val identity: String)
+                public val DiscoveryParamsKey: AttributeKey<DiscoveryParams> = AttributeKey("DiscoveryParams")
+            """.trimIndent(),
+        )
+    }
+
+    @Test
+    fun testDiscoverHost() {
+        val actual = render()
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                public suspend fun discoverHost(client: TestClient): ExpiringValue<Host> =
+                    client.getEndpoints()
+                        .endpoints
+                        ?.map { ep -> ExpiringValue(
+                            Host.parse(ep.address!!),
+                            Instant.now() + ep.cachePeriodInMinutes.minutes,
+                        )}
+                        ?.firstOrNull()
+                        ?: throw EndpointProviderException("Unable to discover any endpoints when invoking getEndpoints!")
+            """.formatForTest(),
+        )
+    }
+
+    private fun render(): String {
+        val model = model()
+        val testCtx = model.newTestContext()
+        val delegator = testCtx.generationCtx.delegator
+        val generator = EndpointDiscovererInterfaceGenerator(testCtx.toCodegenContext(), delegator)
+        generator.render()
+
+        delegator.flushWriters()
+        val testManifest = delegator.fileManifest as MockManifest
+        return testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/TestEndpointDiscoverer.kt")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
index 48fec68de5..1fdb3f3973 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
@@ -36,7 +36,7 @@ class EndpointDiscoveryIntegrationTest {
         val contents = writer.toString()
 
         if (discoveryRequired) {
-            val configStr = "public val endpointDiscoverer: TestEndpointDiscoverer = builder.endpointDiscoverer ?: TestEndpointDiscoverer()"
+            val configStr = "public val endpointDiscoverer: TestEndpointDiscoverer = builder.endpointDiscoverer ?: DefaultTestEndpointDiscoverer()"
             contents.shouldContainOnlyOnceWithDiff(configStr)
 
             val builderStr = """
@@ -52,9 +52,8 @@ class EndpointDiscoveryIntegrationTest {
 
             val builderStr = """
                 /**
-                 * The endpoint discoverer for this client, if applicable. By default, no endpoint
-                 * discovery is provided. To use endpoint discovery, set this to a valid
-                 * [TestEndpointDiscoverer] instance.
+                 * The endpoint discoverer for this client, if applicable. By default, no endpoint discovery is
+                 * provided. To use endpoint discovery, set this to a valid [TestEndpointDiscoverer] instance.
                  */
                 public var endpointDiscoverer: TestEndpointDiscoverer? = null
             """.formatForTest("        ")
@@ -62,6 +61,23 @@ class EndpointDiscoveryIntegrationTest {
         }
     }
 
+    @Test
+    fun testDiscoveredEndpointErrorMiddleware() {
+        val model = model()
+        val ctx = model.newTestContext(integrations = listOf(EndpointDiscoveryIntegration()))
+        val generator = MockHttpProtocolGenerator(model)
+        generator.generateProtocolClient(ctx.generationCtx)
+
+        ctx.generationCtx.delegator.finalize()
+        ctx.generationCtx.delegator.flushWriters()
+
+        val actual = ctx.manifest.expectFileString("/src/main/kotlin/com/test/DefaultTestClient.kt")
+
+        val getFooMethod = actual.lines("    override suspend fun getFoo(input: GetFooRequest): GetFooResponse {", "    }")
+        val expectedInterceptor = "config.endpointDiscoverer?.let { op.interceptors.add(DiscoveredEndpointErrorInterceptor(BadEndpointError::class, it::invalidate)) }"
+        getFooMethod.shouldContainOnlyOnceWithDiff(expectedInterceptor)
+    }
+
     private fun model(discoveryRequired: Boolean = true) =
         """
             namespace com.test
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt
new file mode 100644
index 0000000000..55d58d6cc4
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt
@@ -0,0 +1,56 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import software.amazon.smithy.kotlin.codegen.test.toSmithyModel
+
+fun model() =
+    // language=smithy
+    """
+        namespace com.test
+        
+        use aws.protocols#awsJson1_1
+        use aws.api#service
+        use aws.auth#sigv4
+        
+        @service(sdkId: "test")
+        @sigv4(name: "test")
+        @awsJson1_1
+        @aws.api#clientEndpointDiscovery(
+            operation: GetEndpoints,
+            error: BadEndpointError
+        )
+        service Test {
+            version: "1.0.0",
+            operations: [GetEndpoints]
+        }
+        
+        @error("client")
+        @httpError(421)
+        structure BadEndpointError { }
+        
+        @http(method: "GET", uri: "/endpoints")
+        operation GetEndpoints {
+            input: GetEndpointsInput
+            output: GetEndpointsOutput
+        }
+        
+        @input
+        structure GetEndpointsInput { }
+        
+        @output
+        structure GetEndpointsOutput {
+            Endpoints: Endpoints
+        }
+        
+        list Endpoints {
+            member: Endpoint
+        }
+        
+        structure Endpoint {
+            Address: String
+            CachePeriodInMinutes: Long
+        }
+    """.toSmithyModel()
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
index 95138ad529..097db4b4c8 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
@@ -53,7 +53,8 @@ class HttpStringValuesMapSerializerTest {
 
     @Test
     fun `it handles primitive header shapes when different mode`() {
-        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.HEADER)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.HEADER, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
@@ -68,7 +69,8 @@ class HttpStringValuesMapSerializerTest {
 
     @Test
     fun `it handles primitive query shapes when different mode`() {
-        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.QUERY)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.QUERY, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
@@ -129,7 +131,8 @@ class HttpStringValuesMapSerializerTest {
             }
         """.prependNamespaceAndService(operations = listOf("Foo")).toSmithyModel()
 
-        val contents = getTestContents(model, "com.test#Foo", HttpBinding.Location.HEADER)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(model, "com.test#Foo", HttpBinding.Location.HEADER, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
index 347da007cb..c0eae1f05b 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
@@ -72,7 +72,8 @@ class SerializeStructGeneratorTest {
             }
         """.trimIndent()
 
-        val actual = codegenSerializerForShape(model, "com.test#Foo")
+        val settings = model.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val actual = codegenSerializerForShape(model, "com.test#Foo", settings = settings)
         actual.shouldContainOnlyOnceWithDiff(expected)
     }
 
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
index 49ee90f484..038a2ff7da 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
@@ -11,13 +11,10 @@ import software.amazon.smithy.build.MockManifest
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
-import software.amazon.smithy.kotlin.codegen.core.CodegenContext
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
 import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
-import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.loadModelFromResource
-import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.test.*
-import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.ShapeId
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -130,16 +127,9 @@ class ServiceWaitersGeneratorTest {
         val service = model.getShape(ShapeId.from(TestModelDefault.SERVICE_SHAPE_ID)).get().asServiceShape().get()
         val settings = KotlinSettings(service.id, KotlinSettings.PackageSettings(TestModelDefault.NAMESPACE, TestModelDefault.MODEL_VERSION), sdkId = service.id.name)
 
-        val ctx = object : CodegenContext {
-            override val model: Model = model
-            override val symbolProvider: SymbolProvider = provider
-            override val settings: KotlinSettings = settings
-            override val protocolGenerator: ProtocolGenerator? = null
-            override val integrations: List<KotlinIntegration> = listOf()
-        }
-
         val manifest = MockManifest()
-        val delegator = KotlinDelegator(settings, model, manifest, provider)
+        val ctx = GenerationContext(model, provider, settings, protocolGenerator = null)
+        val delegator = KotlinDelegator(ctx, manifest)
 
         val generator = ServiceWaitersGenerator()
         generator.writeAdditionalFiles(ctx, delegator)
diff --git a/gradle.properties b/gradle.properties
index 8f39c9c434..5760061e6b 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -14,10 +14,10 @@ kotlinx.atomicfu.enableNativeIrTransformation=false
 org.gradle.jvmargs=-Xmx2G -XX:MaxMetaspaceSize=1G
 
 # SDK
-sdkVersion=1.4.24-SNAPSHOT
+sdkVersion=1.5.4-SNAPSHOT
 
 # codegen
-codegenVersion=0.34.24-SNAPSHOT
+codegenVersion=0.35.4-SNAPSHOT
 
 # FIXME Remove after Dokka 2.0 Gradle plugin is stable
 org.jetbrains.dokka.experimental.gradle.pluginMode=V2Enabled
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c801f80d83..bdd68f6896 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,37 +1,37 @@
 [versions]
-kotlin-version = "2.1.0"
+kotlin-version = "2.2.0"
 dokka-version = "2.0.0"
 
-aws-kotlin-repo-tools-version = "0.4.28-kn"
+aws-kotlin-repo-tools-version = "0.4.30-kn"
 
 # libs
-coroutines-version = "1.9.0"
-atomicfu-version = "0.25.0"
-okhttp-version = "5.0.0-alpha.14"
+coroutines-version = "1.10.2"
+atomicfu-version = "0.29.0"
+okhttp-version = "5.1.0"
 okhttp4-version = "4.12.0"
-okio-version = "3.9.1"
+okio-version = "3.16.0"
 otel-version = "1.45.0"
 slf4j-version = "2.0.16"
 slf4j-v1x-version = "1.7.36"
-crt-kotlin-version = "0.9.3-SNAPSHOT"
-micrometer-version = "1.14.2"
-binary-compatibility-validator-version = "0.16.3"
+crt-kotlin-version = "0.10.0"
+micrometer-version = "1.15.2"
+binary-compatibility-validator-version = "0.18.1"
 kotlin-multiplatform-bignum-version = "0.3.10"
 kotlinx-datetime-version = "0.6.1"
 
 # codegen
-smithy-version = "1.60.2"
+smithy-version = "1.61.0"
 
 # testing
-junit-version = "5.10.5"
+junit-version = "5.13.4"
 kotest-version = "5.9.1"
-kotlin-compile-testing-version = "0.7.0"
-kotlinx-benchmark-version = "0.4.12"
+kotlin-compile-testing-version = "0.8.0"
+kotlinx-benchmark-version = "0.4.14"
 kotlinx-serialization-version = "1.7.3"
 docker-java-version = "3.4.0"
-ktor-version = "3.1.1"
+ktor-version = "3.2.3"
 kaml-version = "0.55.0"
-jsoup-version = "1.19.1"
+jsoup-version = "1.21.1"
 
 [libraries]
 aws-kotlin-repo-tools-build-support = { module="aws.sdk.kotlin.gradle:build-support", version.ref = "aws-kotlin-repo-tools-version" }
diff --git a/runtime/auth/aws-credentials/api/aws-credentials.api b/runtime/auth/aws-credentials/api/aws-credentials.api
index 15df96aff6..429f5eec3b 100644
--- a/runtime/auth/aws-credentials/api/aws-credentials.api
+++ b/runtime/auth/aws-credentials/api/aws-credentials.api
@@ -18,9 +18,9 @@ public abstract interface class aws/smithy/kotlin/runtime/auth/awscredentials/Cl
 public abstract interface class aws/smithy/kotlin/runtime/auth/awscredentials/Credentials : aws/smithy/kotlin/runtime/identity/Identity {
 	public static final field Companion Laws/smithy/kotlin/runtime/auth/awscredentials/Credentials$Companion;
 	public abstract fun getAccessKeyId ()Ljava/lang/String;
-	public abstract fun getProviderName ()Ljava/lang/String;
+	public fun getProviderName ()Ljava/lang/String;
 	public abstract fun getSecretAccessKey ()Ljava/lang/String;
-	public abstract fun getSessionToken ()Ljava/lang/String;
+	public fun getSessionToken ()Ljava/lang/String;
 }
 
 public final class aws/smithy/kotlin/runtime/auth/awscredentials/Credentials$Companion {
diff --git a/runtime/auth/aws-signing-common/api/aws-signing-common.api b/runtime/auth/aws-signing-common/api/aws-signing-common.api
index c9353509be..046afa8c53 100644
--- a/runtime/auth/aws-signing-common/api/aws-signing-common.api
+++ b/runtime/auth/aws-signing-common/api/aws-signing-common.api
@@ -199,13 +199,6 @@ public final class aws/smithy/kotlin/runtime/auth/awssigning/PresignerKt {
 	public static final fun presignRequest (Laws/smithy/kotlin/runtime/http/request/HttpRequestBuilder;Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProvider;Laws/smithy/kotlin/runtime/http/operation/EndpointResolver;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigner;Lkotlin/jvm/functions/Function1;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public final class aws/smithy/kotlin/runtime/auth/awssigning/UnsupportedSigningAlgorithmException : aws/smithy/kotlin/runtime/ClientException {
-	public fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;)V
-	public fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;Ljava/lang/Throwable;)V
-	public synthetic fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;Ljava/lang/Throwable;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public final fun getSigningAlgorithm ()Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;
-}
-
 public final class aws/smithy/kotlin/runtime/auth/awssigning/internal/AwsChunkedUtilKt {
 	public static final field AWS_CHUNKED_THRESHOLD I
 	public static final field CHUNK_SIZE_BYTES I
diff --git a/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt b/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt
deleted file mode 100644
index 8ff8c1e35f..0000000000
--- a/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package aws.smithy.kotlin.runtime.auth.awssigning
-
-import aws.smithy.kotlin.runtime.ClientException
-import aws.smithy.kotlin.runtime.InternalApi
-
-/**
- * Is thrown when a signing algorithm is not supported by a signer
- *
- * See: [AwsSigningAlgorithm], [AwsSigner]
- *
- * @param message The message displayed by the exception
- * @param signingAlgorithm The unsupported signing algorithm
- * @param cause The cause of the exception
- */
-@InternalApi
-@Deprecated("This exception is no longer thrown. It will be removed in the next minor version, v1.5.x.")
-public class UnsupportedSigningAlgorithmException(
-    message: String,
-    public val signingAlgorithm: AwsSigningAlgorithm,
-    cause: Throwable? = null,
-) : ClientException(
-    message,
-    cause,
-) {
-    public constructor(
-        message: String,
-        signingAlgorithm: AwsSigningAlgorithm,
-    ) : this (
-        message,
-        signingAlgorithm,
-        null,
-    )
-}
diff --git a/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt b/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
index 4f4239a2ce..c4fe4f5ca4 100644
--- a/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
+++ b/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
@@ -5,7 +5,7 @@
 package aws.smithy.kotlin.runtime.auth.awssigning
 
 import aws.smithy.kotlin.runtime.auth.awscredentials.Credentials
-import aws.smithy.kotlin.runtime.collections.ReadThroughCache
+import aws.smithy.kotlin.runtime.collections.PeriodicSweepCache
 import aws.smithy.kotlin.runtime.content.BigInteger
 import aws.smithy.kotlin.runtime.hashing.HashSupplier
 import aws.smithy.kotlin.runtime.hashing.Sha256
@@ -32,7 +32,7 @@ internal val N_MINUS_TWO = "FFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9
  * @param sha256Provider the [HashSupplier] to use for computing SHA-256 hashes
  */
 internal class SigV4aSignatureCalculator(override val sha256Provider: HashSupplier = ::Sha256) : BaseSigV4SignatureCalculator(AwsSigningAlgorithm.SIGV4_ASYMMETRIC, sha256Provider) {
-    private val privateKeyCache = ReadThroughCache<Credentials, ByteArray>(
+    private val privateKeyCache = PeriodicSweepCache<Credentials, ByteArray>(
         minimumSweepPeriod = 1.hours, // note: Sweeps are effectively a no-op because expiration is [Instant.MAX_VALUE]
     )
 
diff --git a/runtime/auth/aws-signing-tests/build.gradle.kts b/runtime/auth/aws-signing-tests/build.gradle.kts
index 5810181041..667021303e 100644
--- a/runtime/auth/aws-signing-tests/build.gradle.kts
+++ b/runtime/auth/aws-signing-tests/build.gradle.kts
@@ -17,7 +17,6 @@ kotlin {
                 api(project(":runtime:auth:http-auth-aws"))
                 implementation(libs.kotlin.test)
                 implementation(libs.kotlinx.coroutines.test)
-                implementation(libs.junit.jupiter.params)
             }
         }
 
@@ -28,6 +27,7 @@ kotlin {
                 implementation(libs.ktor.http.cio)
                 implementation(libs.ktor.utils)
                 implementation(libs.kotlin.test.junit5)
+                implementation(libs.junit.jupiter.params)
                 implementation(libs.kotlinx.serialization.json)
             }
         }
diff --git a/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt b/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
index b3c4202d26..70d48bfe45 100644
--- a/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
+++ b/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
@@ -11,7 +11,9 @@ import aws.smithy.kotlin.runtime.auth.awssigning.*
 import aws.smithy.kotlin.runtime.collections.Attributes
 import aws.smithy.kotlin.runtime.collections.ValuesMap
 import aws.smithy.kotlin.runtime.collections.get
-import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.HttpBody
+import aws.smithy.kotlin.runtime.http.HttpMethod
+import aws.smithy.kotlin.runtime.http.SdkHttpClient
 import aws.smithy.kotlin.runtime.http.auth.AwsHttpSigner
 import aws.smithy.kotlin.runtime.http.auth.SigV4AuthScheme
 import aws.smithy.kotlin.runtime.http.operation.*
@@ -24,9 +26,7 @@ import aws.smithy.kotlin.runtime.net.url.Url
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import aws.smithy.kotlin.runtime.time.Instant
 import io.ktor.http.cio.*
-import io.ktor.util.*
 import io.ktor.utils.io.*
-import io.ktor.utils.io.core.*
 import kotlinx.coroutines.runBlocking
 import kotlinx.io.readByteArray
 import kotlinx.serialization.json.*
@@ -420,8 +420,7 @@ private fun buildOperation(
         serializeWith = object : HttpSerializer.NonStreaming<Unit> {
             override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder = serialized
         }
-        @Suppress("DEPRECATION")
-        deserializer = IdentityDeserializer
+        deserializeWith = HttpDeserializer.Identity
 
         context {
             operationName = "testSigningOperation"
diff --git a/runtime/auth/http-auth-api/api/http-auth-api.api b/runtime/auth/http-auth-api/api/http-auth-api.api
index 491aa48555..2f541fb6ef 100644
--- a/runtime/auth/http-auth-api/api/http-auth-api.api
+++ b/runtime/auth/http-auth-api/api/http-auth-api.api
@@ -1,7 +1,7 @@
 public abstract interface class aws/smithy/kotlin/runtime/http/auth/AuthScheme {
 	public abstract fun getSchemeId-DepwgT4 ()Ljava/lang/String;
 	public abstract fun getSigner ()Laws/smithy/kotlin/runtime/http/auth/HttpSigner;
-	public abstract fun identityProvider (Laws/smithy/kotlin/runtime/identity/IdentityProviderConfig;)Laws/smithy/kotlin/runtime/identity/IdentityProvider;
+	public fun identityProvider (Laws/smithy/kotlin/runtime/identity/IdentityProviderConfig;)Laws/smithy/kotlin/runtime/identity/IdentityProvider;
 }
 
 public final class aws/smithy/kotlin/runtime/http/auth/AuthScheme$DefaultImpls {
diff --git a/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt b/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
index 6797ed74fb..0daa2b31fe 100644
--- a/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
+++ b/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
@@ -38,13 +38,11 @@ class DefaultAwsHttpSignerTest : AwsHttpSignerTestBase(DefaultAwsSigner)
  * Basic sanity tests. Signing (including `AwsHttpSigner`) is covered by the more exhaustive
  * test suite in the `aws-signing-tests` module.
  */
-@Suppress("HttpUrlsUsage")
 public abstract class AwsHttpSignerTestBase(
     private val signer: AwsSigner,
 ) {
     private val testCredentials = Credentials("AKID", "SECRET", "SESSION")
 
-    @Suppress("DEPRECATION")
     private fun buildOperation(
         requestBody: String = "{\"TableName\": \"foo\"}",
         streaming: Boolean = false,
@@ -52,29 +50,11 @@ public abstract class AwsHttpSignerTestBase(
         unsigned: Boolean = false,
     ): SdkHttpOperation<Unit, HttpResponse> {
         val operation: SdkHttpOperation<Unit, HttpResponse> = SdkHttpOperation.build {
-            serializer = object : HttpSerialize<Unit> {
-                override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
-                    HttpRequestBuilder().apply {
-                        method = HttpMethod.POST
-                        url.scheme = Scheme.HTTP
-                        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
-                        url.path.encoded = "/"
-                        headers.append("Host", "demo.us-east-1.amazonaws.com")
-                        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
-                        body = when (streaming) {
-                            true -> {
-                                object : HttpBody.ChannelContent() {
-                                    override val contentLength: Long = requestBody.length.toLong()
-                                    override fun readFrom(): SdkByteReadChannel = SdkByteReadChannel(requestBody.encodeToByteArray())
-                                    override val isOneShot: Boolean = !replayable
-                                }
-                            }
-                            false -> HttpBody.fromBytes(requestBody.encodeToByteArray())
-                        }
-                        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
-                    }
+            serializeWith = when (streaming) {
+                true -> StreamingSerializer(requestBody, replayable)
+                false -> NonStreamingSerializer(requestBody)
             }
-            deserializer = IdentityDeserializer
+            deserializeWith = HttpDeserializer.Identity
             operationName = "testSigningOperation"
             serviceName = "testService"
             context {
@@ -190,3 +170,36 @@ public abstract class AwsHttpSignerTestBase(
         assertEquals(expectedSig, signed.headers["Authorization"])
     }
 }
+
+private class NonStreamingSerializer(private val requestBody: String) : HttpSerializer.NonStreaming<Unit> {
+    override fun serialize(context: ExecutionContext, input: Unit) = HttpRequestBuilder().apply {
+        method = HttpMethod.POST
+        url.scheme = Scheme.HTTP
+        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
+        url.path.encoded = "/"
+        body = HttpBody.fromBytes(requestBody.encodeToByteArray())
+        headers.append("Host", "demo.us-east-1.amazonaws.com")
+        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
+        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
+    }
+}
+
+private class StreamingSerializer(
+    private val requestBody: String,
+    private val replayable: Boolean,
+) : HttpSerializer.Streaming<Unit> {
+    override suspend fun serialize(context: ExecutionContext, input: Unit) = HttpRequestBuilder().apply {
+        method = HttpMethod.POST
+        url.scheme = Scheme.HTTP
+        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
+        url.path.encoded = "/"
+        body = object : HttpBody.ChannelContent() {
+            override val contentLength: Long = requestBody.length.toLong()
+            override fun readFrom(): SdkByteReadChannel = SdkByteReadChannel(requestBody.encodeToByteArray())
+            override val isOneShot: Boolean = !replayable
+        }
+        headers.append("Host", "demo.us-east-1.amazonaws.com")
+        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
+        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
+    }
+}
diff --git a/runtime/auth/identity-api/api/identity-api.api b/runtime/auth/identity-api/api/identity-api.api
index 9b07562934..824dc99385 100644
--- a/runtime/auth/identity-api/api/identity-api.api
+++ b/runtime/auth/identity-api/api/identity-api.api
@@ -56,6 +56,7 @@ public final class aws/smithy/kotlin/runtime/identity/IdentityAttributesKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/identity/IdentityProvider {
 	public abstract fun resolve (Laws/smithy/kotlin/runtime/collections/Attributes;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun resolve$default (Laws/smithy/kotlin/runtime/identity/IdentityProvider;Laws/smithy/kotlin/runtime/collections/Attributes;Lkotlin/coroutines/Continuation;ILjava/lang/Object;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/identity/IdentityProvider$DefaultImpls {
diff --git a/runtime/build.gradle.kts b/runtime/build.gradle.kts
index e5674f748f..949c95973e 100644
--- a/runtime/build.gradle.kts
+++ b/runtime/build.gradle.kts
@@ -74,6 +74,7 @@ subprojects {
             freeCompilerArgs.add("-Xexpect-actual-classes")
         }
     }
+
     tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinNativeCompile> {
         compilerOptions {
             freeCompilerArgs.add("-Xexpect-actual-classes")
diff --git a/runtime/observability/telemetry-api/api/telemetry-api.api b/runtime/observability/telemetry-api/api/telemetry-api.api
index 470061210b..5e1f6b8684 100644
--- a/runtime/observability/telemetry-api/api/telemetry-api.api
+++ b/runtime/observability/telemetry-api/api/telemetry-api.api
@@ -176,11 +176,16 @@ public abstract interface class aws/smithy/kotlin/runtime/telemetry/logging/Logg
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/logging/Logger$Companion;
 	public abstract fun atLevel (Laws/smithy/kotlin/runtime/telemetry/logging/LogLevel;)Laws/smithy/kotlin/runtime/telemetry/logging/LogRecordBuilder;
 	public abstract fun debug (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun debug$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun error (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun error$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun info (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun info$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun isEnabledFor (Laws/smithy/kotlin/runtime/telemetry/logging/LogLevel;)Z
 	public abstract fun trace (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun trace$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun warn (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun warn$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/logging/Logger$Companion {
@@ -266,6 +271,7 @@ public abstract class aws/smithy/kotlin/runtime/telemetry/metrics/AbstractUpDown
 
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement {
 	public abstract fun record (Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun record$default (Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement;Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement$DefaultImpls {
@@ -284,6 +290,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementH
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/Histogram {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram$Companion;
 	public abstract fun record (Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun record$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/Histogram$Companion {
@@ -307,12 +314,19 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/HistogramKt {
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/Meter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/Meter$Companion;
 	public abstract fun createAsyncUpDownCounter (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createAsyncUpDownCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createDoubleGauge (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createDoubleGauge$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createDoubleHistogram (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
+	public static synthetic fun createDoubleHistogram$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
 	public abstract fun createLongGauge (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createLongGauge$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createLongHistogram (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
+	public static synthetic fun createLongHistogram$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
 	public abstract fun createMonotonicCounter (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;
+	public static synthetic fun createMonotonicCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;
 	public abstract fun createUpDownCounter (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;
+	public static synthetic fun createUpDownCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/Meter$Companion {
@@ -341,6 +355,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/MeterProvider$Com
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$Companion;
 	public abstract fun add (JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun add$default (Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$Companion {
@@ -354,6 +369,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter$Companion;
 	public abstract fun add (JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun add$default (Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter$Companion {
@@ -427,9 +443,10 @@ public final class aws/smithy/kotlin/runtime/telemetry/trace/SpanStatus : java/l
 
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/trace/TraceSpan : aws/smithy/kotlin/runtime/telemetry/context/Scope {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan$Companion;
-	public abstract fun asContextElement ()Lkotlin/coroutines/CoroutineContext;
+	public fun asContextElement ()Lkotlin/coroutines/CoroutineContext;
 	public abstract fun close ()V
 	public abstract fun emitEvent (Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;)V
+	public static synthetic fun emitEvent$default (Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;ILjava/lang/Object;)V
 	public abstract fun getSpanContext ()Laws/smithy/kotlin/runtime/telemetry/trace/SpanContext;
 	public abstract fun mergeAttributes (Laws/smithy/kotlin/runtime/collections/Attributes;)V
 	public abstract fun set (Laws/smithy/kotlin/runtime/collections/AttributeKey;Ljava/lang/Object;)V
@@ -468,6 +485,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/trace/TraceSpanExtKt {
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/trace/Tracer {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/trace/Tracer$Companion;
 	public abstract fun createSpan (Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/trace/SpanKind;Laws/smithy/kotlin/runtime/telemetry/context/Context;)Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;
+	public static synthetic fun createSpan$default (Laws/smithy/kotlin/runtime/telemetry/trace/Tracer;Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/trace/SpanKind;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/trace/Tracer$Companion {
diff --git a/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt b/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
index b26ed992af..344ce79e0d 100644
--- a/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
+++ b/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
@@ -6,8 +6,10 @@
 package aws.smithy.kotlin.runtime.awsprotocol.json
 
 import aws.smithy.kotlin.runtime.collections.get
-import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.HttpBody
+import aws.smithy.kotlin.runtime.http.SdkHttpClient
 import aws.smithy.kotlin.runtime.http.operation.*
+import aws.smithy.kotlin.runtime.http.readAll
 import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
 import aws.smithy.kotlin.runtime.http.response.HttpResponse
 import aws.smithy.kotlin.runtime.httptest.TestEngine
@@ -19,10 +21,9 @@ import kotlin.test.assertEquals
 class AwsJsonProtocolTest {
     @Test
     fun testSetJsonProtocolHeaders() = runTest {
-        @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = UnitSerializer
-            deserializer = IdentityDeserializer
+            serializeWith = HttpSerializer.Unit
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
@@ -41,10 +42,9 @@ class AwsJsonProtocolTest {
 
     @Test
     fun testEmptyBody() = runTest {
-        @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = UnitSerializer
-            deserializer = IdentityDeserializer
+            serializeWith = HttpSerializer.Unit
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
@@ -62,14 +62,14 @@ class AwsJsonProtocolTest {
     fun testDoesNotOverride() = runTest {
         @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = object : HttpSerialize<Unit> {
-                override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
+            serializeWith = object : HttpSerializer.NonStreaming<Unit> {
+                override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
                     HttpRequestBuilder().apply {
                         headers["Content-Type"] = "application/xml"
                         body = HttpBody.fromBytes("foo".encodeToByteArray())
                     }
             }
-            deserializer = IdentityDeserializer
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
diff --git a/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api b/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
index 7325432724..ab7db70f5a 100644
--- a/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
+++ b/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
@@ -1,10 +1,8 @@
 public final class aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerKt {
-	public static final fun parseEc2QueryErrorResponse ([BLkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static final fun parseEc2QueryErrorResponseNoSuspend ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
+	public static final fun parseEc2QueryErrorResponse ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
 }
 
 public final class aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerKt {
-	public static final fun parseRestXmlErrorResponse ([BLkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static final fun parseRestXmlErrorResponseNoSuspend ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
+	public static final fun parseRestXmlErrorResponse ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
 }
 
diff --git a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
index 63391e1b12..2bd349177c 100644
--- a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
+++ b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
@@ -7,18 +7,16 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
 import aws.smithy.kotlin.runtime.serde.getOrDeserializeErr
-import aws.smithy.kotlin.runtime.serde.xml.*
+import aws.smithy.kotlin.runtime.serde.xml.XmlTagReader
+import aws.smithy.kotlin.runtime.serde.xml.data
+import aws.smithy.kotlin.runtime.serde.xml.xmlTagReader
 
 internal data class Ec2QueryErrorResponse(val errors: List<Ec2QueryError>, val requestId: String?)
 
 internal data class Ec2QueryError(val code: String?, val message: String?)
 
-@Deprecated("use parseEc2QueryErrorResponseNoSuspend")
 @InternalApi
-public suspend fun parseEc2QueryErrorResponse(payload: ByteArray): ErrorDetails =
-    parseEc2QueryErrorResponseNoSuspend(payload)
-
-public fun parseEc2QueryErrorResponseNoSuspend(payload: ByteArray): ErrorDetails {
+public fun parseEc2QueryErrorResponse(payload: ByteArray): ErrorDetails {
     val response = Ec2QueryErrorResponseDeserializer.deserialize(xmlTagReader(payload))
     val firstError = response.errors.firstOrNull()
     return ErrorDetails(firstError?.code, firstError?.message, response.requestId)
diff --git a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
index 99925c0dc1..74a9448146 100644
--- a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
+++ b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
@@ -6,7 +6,7 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
-import aws.smithy.kotlin.runtime.serde.*
+import aws.smithy.kotlin.runtime.serde.getOrDeserializeErr
 import aws.smithy.kotlin.runtime.serde.xml.XmlTagReader
 import aws.smithy.kotlin.runtime.serde.xml.data
 import aws.smithy.kotlin.runtime.serde.xml.xmlTagReader
@@ -26,18 +26,8 @@ internal data class XmlError(
     override val message: String?,
 ) : RestXmlErrorDetails
 
-/**
- * Deserializes rest XML protocol errors as specified by:
- * https://awslabs.github.io/smithy/1.0/spec/aws/aws-restxml-protocol.html#error-response-serialization
- *
- * Returns parsed data in normalized form or throws [DeserializationException] if response cannot be parsed.
- */
-@Deprecated("use parseRestXmlErrorResponseNoSuspend")
 @InternalApi
-public suspend fun parseRestXmlErrorResponse(payload: ByteArray): ErrorDetails =
-    parseRestXmlErrorResponseNoSuspend(payload)
-
-public fun parseRestXmlErrorResponseNoSuspend(payload: ByteArray): ErrorDetails {
+public fun parseRestXmlErrorResponse(payload: ByteArray): ErrorDetails {
     val details = XmlErrorDeserializer.deserialize(xmlTagReader(payload))
     return ErrorDetails(details.code, details.message, details.requestId)
 }
diff --git a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
index 6dfb531a5a..d2b4a6972e 100644
--- a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
+++ b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
@@ -26,7 +26,7 @@ class Ec2QueryErrorDeserializerTest {
                 <RequestId>foo-request</RequestId>
             </Response>
         """.trimIndent().encodeToByteArray()
-        val actual = parseEc2QueryErrorResponseNoSuspend(payload)
+        val actual = parseEc2QueryErrorResponse(payload)
         assertEquals("InvalidGreeting", actual.code)
         assertEquals("Hi", actual.message)
         assertEquals("foo-request", actual.requestId)
@@ -61,7 +61,7 @@ class Ec2QueryErrorDeserializerTest {
 
         for (payload in tests) {
             assertFailsWith<DeserializationException> {
-                parseEc2QueryErrorResponseNoSuspend(payload)
+                parseEc2QueryErrorResponse(payload)
             }
         }
     }
@@ -90,7 +90,7 @@ class Ec2QueryErrorDeserializerTest {
         ).map { it.trimIndent().encodeToByteArray() }
 
         for (payload in tests) {
-            val actual = parseEc2QueryErrorResponseNoSuspend(payload)
+            val actual = parseEc2QueryErrorResponse(payload)
             assertNull(actual.code)
             assertNull(actual.message)
             assertEquals("foo-request", actual.requestId)
diff --git a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
index 9b94c7c31c..1f08e7bd3c 100644
--- a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
+++ b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
@@ -6,7 +6,10 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 
 import aws.smithy.kotlin.runtime.serde.DeserializationException
 import kotlinx.coroutines.test.runTest
-import kotlin.test.*
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+import kotlin.test.assertNull
 
 class RestXmlErrorDeserializerTest {
 
@@ -36,7 +39,7 @@ class RestXmlErrorDeserializerTest {
         )
 
         for (payload in tests) {
-            val actual = parseRestXmlErrorResponseNoSuspend(payload)
+            val actual = parseRestXmlErrorResponse(payload)
             assertEquals("InvalidGreeting", actual.code)
             assertEquals("Hi", actual.message)
             assertEquals("foo-id", actual.requestId)
@@ -70,7 +73,7 @@ class RestXmlErrorDeserializerTest {
 
         for (payload in tests) {
             assertFailsWith<DeserializationException> {
-                parseRestXmlErrorResponseNoSuspend(payload)
+                parseRestXmlErrorResponse(payload)
             }
         }
     }
@@ -92,7 +95,7 @@ class RestXmlErrorDeserializerTest {
         )
 
         for (payload in tests) {
-            val error = parseRestXmlErrorResponseNoSuspend(payload)
+            val error = parseRestXmlErrorResponse(payload)
             assertEquals("foo-id", error.requestId)
             assertNull(error.code)
             assertNull(error.message)
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api b/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
index 25c2339550..77e6120478 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
@@ -87,7 +87,7 @@ public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConf
 }
 
 public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineKt {
-	public static final fun buildClient (Laws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConfig;Laws/smithy/kotlin/runtime/http/engine/internal/HttpClientMetrics;)Lokhttp3/OkHttpClient;
+	public static final fun buildClient (Laws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConfig;Laws/smithy/kotlin/runtime/http/engine/internal/HttpClientMetrics;[Lokhttp3/EventListener;)Lokhttp3/OkHttpClient;
 }
 
 public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpHeadersAdapter : aws/smithy/kotlin/runtime/http/Headers {
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
similarity index 78%
rename from runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt
rename to runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
index 3f4c366f70..131466e66e 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
@@ -4,12 +4,10 @@
  */
 package aws.smithy.kotlin.runtime.http.engine.okhttp
 
+import aws.smithy.kotlin.runtime.io.Closeable
 import aws.smithy.kotlin.runtime.telemetry.logging.logger
 import kotlinx.coroutines.*
-import okhttp3.Call
-import okhttp3.Connection
-import okhttp3.ConnectionListener
-import okhttp3.ExperimentalOkHttpApi
+import okhttp3.*
 import okhttp3.internal.closeQuietly
 import okio.IOException
 import okio.buffer
@@ -22,12 +20,20 @@ import kotlin.coroutines.coroutineContext
 import kotlin.time.Duration
 import kotlin.time.measureTime
 
-@OptIn(ExperimentalOkHttpApi::class)
-internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionListener() {
+/**
+ * An [okhttp3.EventListener] implementation that monitors connections for remote closure.
+ * This replaces the functionality previously provided by the now-internal [okhttp3.ConnectionListener].
+ */
+internal class ConnectionMonitoringEventListener(private val pollInterval: Duration) :
+    EventListener(),
+    Closeable {
     private val monitorScope = CoroutineScope(Dispatchers.IO + SupervisorJob())
     private val monitors = ConcurrentHashMap<Connection, Job>()
 
-    fun close(): Unit = runBlocking {
+    /**
+     * Close all active connection monitors.
+     */
+    override fun close(): Unit = runBlocking {
         val monitorJob = requireNotNull(monitorScope.coroutineContext[Job]) {
             "Connection idle monitor scope cannot be cancelled because it does not have a job: $this"
         }
@@ -40,13 +46,16 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
             ?.callContext
             ?: Dispatchers.IO
 
-    override fun connectionAcquired(connection: Connection, call: Call) {
+    // Cancel monitoring when a connection is acquired
+    override fun connectionAcquired(call: Call, connection: Connection) {
+        super.connectionAcquired(call, connection)
+
         // Non-locking map access is okay here because this code will only execute synchronously as part of a
         // `connectionAcquired` event and will be complete before any future `connectionReleased` event could fire for
         // the same connection.
         monitors.remove(connection)?.let { monitor ->
             val context = call.callContext()
-            val logger = context.logger<ConnectionIdleMonitor>()
+            val logger = context.logger<ConnectionMonitoringEventListener>()
             logger.trace { "Cancel monitoring for $connection" }
 
             // Use `runBlocking` because this _must_ finish before OkHttp goes to use the connection
@@ -58,13 +67,18 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
         }
     }
 
-    override fun connectionReleased(connection: Connection, call: Call) {
+    // Start monitoring when a connection is released
+    override fun connectionReleased(call: Call, connection: Connection) {
+        super.connectionReleased(call, connection)
+
         val connId = System.identityHashCode(connection)
         val callContext = call.callContext()
+
+        // Start monitoring
         val monitor = monitorScope.launch(CoroutineName("okhttp-conn-monitor-for-$connId")) {
             doMonitor(connection, callContext)
         }
-        callContext.logger<ConnectionIdleMonitor>().trace { "Launched coroutine $monitor to monitor $connection" }
+        callContext.logger<ConnectionMonitoringEventListener>().trace { "Launched coroutine $monitor to monitor $connection" }
 
         // Non-locking map access is okay here because this code will only execute synchronously as part of a
         // `connectionReleased` event and will be complete before any future `connectionAcquired` event could fire for
@@ -73,7 +87,7 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
     }
 
     private suspend fun doMonitor(conn: Connection, callContext: CoroutineContext) {
-        val logger = callContext.logger<ConnectionIdleMonitor>()
+        val logger = callContext.logger<ConnectionMonitoringEventListener>()
 
         val socket = conn.socket()
         val source = try {
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt
new file mode 100644
index 0000000000..c18bd331f3
--- /dev/null
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt
@@ -0,0 +1,115 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.http.engine.okhttp
+
+import aws.smithy.kotlin.runtime.io.closeIfCloseable
+import okhttp3.*
+import java.io.IOException
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.net.Proxy
+
+/**
+ * An [okhttp3.EventListener] that delegates to a chain of EventListeners.
+ * Start events are sent in forward order, terminal events are sent in reverse order
+ */
+internal class EventListenerChain(
+    private val listeners: List<EventListener>,
+) : EventListener() {
+    private val reverseListeners = listeners.reversed()
+
+    fun close() {
+        listeners.forEach {
+            it.closeIfCloseable()
+        }
+    }
+
+    override fun callStart(call: Call): Unit =
+        listeners.forEach { it.callStart(call) }
+
+    override fun dnsStart(call: Call, domainName: String): Unit =
+        listeners.forEach { it.dnsStart(call, domainName) }
+
+    override fun dnsEnd(call: Call, domainName: String, inetAddressList: List<InetAddress>): Unit =
+        reverseListeners.forEach { it.dnsEnd(call, domainName, inetAddressList) }
+
+    override fun proxySelectStart(call: Call, url: HttpUrl): Unit =
+        listeners.forEach { it.proxySelectStart(call, url) }
+
+    override fun proxySelectEnd(call: Call, url: HttpUrl, proxies: List<Proxy>): Unit =
+        reverseListeners.forEach { it.proxySelectEnd(call, url, proxies) }
+
+    override fun connectStart(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy): Unit =
+        listeners.forEach { it.connectStart(call, inetSocketAddress, proxy) }
+
+    override fun secureConnectStart(call: Call): Unit =
+        listeners.forEach { it.secureConnectStart(call) }
+
+    override fun secureConnectEnd(call: Call, handshake: Handshake?): Unit =
+        reverseListeners.forEach { it.secureConnectEnd(call, handshake) }
+
+    override fun connectEnd(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?): Unit =
+        reverseListeners.forEach { it.connectEnd(call, inetSocketAddress, proxy, protocol) }
+
+    override fun connectFailed(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?, ioe: IOException): Unit =
+        reverseListeners.forEach { it.connectFailed(call, inetSocketAddress, proxy, protocol, ioe) }
+
+    override fun connectionAcquired(call: Call, connection: Connection): Unit =
+        listeners.forEach { it.connectionAcquired(call, connection) }
+
+    override fun connectionReleased(call: Call, connection: Connection): Unit =
+        reverseListeners.forEach { it.connectionReleased(call, connection) }
+
+    override fun requestHeadersStart(call: Call): Unit =
+        listeners.forEach { it.requestHeadersStart(call) }
+
+    override fun requestHeadersEnd(call: Call, request: Request): Unit =
+        reverseListeners.forEach { it.requestHeadersEnd(call, request) }
+
+    override fun requestBodyStart(call: Call): Unit =
+        listeners.forEach { it.requestBodyStart(call) }
+
+    override fun requestBodyEnd(call: Call, byteCount: Long): Unit =
+        reverseListeners.forEach { it.requestBodyEnd(call, byteCount) }
+
+    override fun requestFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.requestFailed(call, ioe) }
+
+    override fun responseHeadersStart(call: Call): Unit =
+        listeners.forEach { it.responseHeadersStart(call) }
+
+    override fun responseHeadersEnd(call: Call, response: Response): Unit =
+        reverseListeners.forEach { it.responseHeadersEnd(call, response) }
+
+    override fun responseBodyStart(call: Call): Unit =
+        listeners.forEach { it.responseBodyStart(call) }
+
+    override fun responseBodyEnd(call: Call, byteCount: Long): Unit =
+        reverseListeners.forEach { it.responseBodyEnd(call, byteCount) }
+
+    override fun responseFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.responseFailed(call, ioe) }
+
+    override fun callEnd(call: Call): Unit =
+        reverseListeners.forEach { it.callEnd(call) }
+
+    override fun callFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.callFailed(call, ioe) }
+
+    override fun canceled(call: Call): Unit =
+        reverseListeners.forEach { it.canceled(call) }
+
+    override fun satisfactionFailure(call: Call, response: Response): Unit =
+        reverseListeners.forEach { it.satisfactionFailure(call, response) }
+
+    override fun cacheConditionalHit(call: Call, cachedResponse: Response): Unit =
+        listeners.forEach { it.cacheConditionalHit(call, cachedResponse) }
+
+    override fun cacheHit(call: Call, response: Response): Unit =
+        listeners.forEach { it.cacheHit(call, response) }
+
+    override fun cacheMiss(call: Call): Unit =
+        listeners.forEach { it.cacheMiss(call) }
+}
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
index a20387d0a0..297e015eed 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
@@ -8,9 +8,13 @@ package aws.smithy.kotlin.runtime.http.engine.okhttp
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.http.HttpCall
 import aws.smithy.kotlin.runtime.http.config.EngineFactory
-import aws.smithy.kotlin.runtime.http.engine.*
+import aws.smithy.kotlin.runtime.http.engine.AlpnId
+import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineBase
+import aws.smithy.kotlin.runtime.http.engine.TlsContext
+import aws.smithy.kotlin.runtime.http.engine.callContext
 import aws.smithy.kotlin.runtime.http.engine.internal.HttpClientMetrics
 import aws.smithy.kotlin.runtime.http.request.HttpRequest
+import aws.smithy.kotlin.runtime.io.closeIfCloseable
 import aws.smithy.kotlin.runtime.net.TlsVersion
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import aws.smithy.kotlin.runtime.time.Instant
@@ -18,7 +22,6 @@ import aws.smithy.kotlin.runtime.time.fromEpochMilliseconds
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.job
 import okhttp3.*
-import okhttp3.ConnectionPool
 import okhttp3.coroutines.executeAsync
 import java.util.concurrent.TimeUnit
 import kotlin.time.toJavaDuration
@@ -44,9 +47,14 @@ public class OkHttpEngine(
         override val engineConstructor: (OkHttpEngineConfig.Builder.() -> Unit) -> OkHttpEngine = ::invoke
     }
 
+    // Create a single shared connection monitoring listener if idle polling is enabled
+    private val connectionMonitoringListener: EventListener? =
+        config.connectionIdlePollingInterval?.let {
+            ConnectionMonitoringEventListener(it)
+        }
+
     private val metrics = HttpClientMetrics(TELEMETRY_SCOPE, config.telemetryProvider)
-    private val connectionIdleMonitor = config.connectionIdlePollingInterval?.let { ConnectionIdleMonitor(it) }
-    private val client = config.buildClientWithConnectionListener(metrics, connectionIdleMonitor)
+    private val client = config.buildClient(metrics, connectionMonitoringListener)
 
     @OptIn(ExperimentalCoroutinesApi::class)
     override suspend fun roundTrip(context: ExecutionContext, request: HttpRequest): HttpCall {
@@ -73,16 +81,20 @@ public class OkHttpEngine(
     }
 
     override fun shutdown() {
-        connectionIdleMonitor?.close()
+        connectionMonitoringListener?.closeIfCloseable()
         client.connectionPool.evictAll()
         client.dispatcher.executorService.shutdown()
         metrics.close()
     }
 }
 
-private fun OkHttpEngineConfig.buildClientFromConfig(
+/**
+ * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
+ */
+@InternalApi
+public fun OkHttpEngineConfig.buildClient(
     metrics: HttpClientMetrics,
-    poolOverride: ConnectionPool? = null,
+    vararg clientScopedEventListeners: EventListener?,
 ): OkHttpClient {
     val config = this
 
@@ -102,7 +114,7 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
         writeTimeout(config.socketWriteTimeout.toJavaDuration())
 
         // use our own pool configured with the timeout settings taken from config
-        val pool = poolOverride ?: ConnectionPool(
+        val pool = ConnectionPool(
             maxIdleConnections = 5, // The default from the no-arg ConnectionPool() constructor
             keepAliveDuration = config.connectionIdleTimeout.inWholeMilliseconds,
             TimeUnit.MILLISECONDS,
@@ -116,7 +128,14 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
         dispatcher(dispatcher)
 
         // Log events coming from okhttp. Allocate a new listener per-call to facilitate dedicated trace spans.
-        eventListenerFactory { call -> HttpEngineEventListener(pool, config.hostResolver, dispatcher, metrics, call) }
+        eventListenerFactory { call ->
+            EventListenerChain(
+                listOfNotNull(
+                    HttpEngineEventListener(pool, config.hostResolver, dispatcher, metrics, call),
+                    *clientScopedEventListeners,
+                ),
+            )
+        }
 
         // map protocols
         if (config.tlsContext.alpn.isNotEmpty()) {
@@ -140,34 +159,6 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
     }.build()
 }
 
-/**
- * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
- */
-// Used by OkHttp4Engine - OkHttp4 does NOT have `connectionListener`
-// TODO - Refactor in next minor version - Move this to OkHttp4Engine and make it private
-@InternalApi
-public fun OkHttpEngineConfig.buildClient(
-    metrics: HttpClientMetrics,
-): OkHttpClient = this.buildClientFromConfig(metrics)
-
-/**
- * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
- */
-// Used by OkHttpEngine - OkHttp5 does have `connectionListener`
-@OptIn(ExperimentalOkHttpApi::class)
-private fun OkHttpEngineConfig.buildClientWithConnectionListener(
-    metrics: HttpClientMetrics,
-    connectionListener: ConnectionIdleMonitor?,
-): OkHttpClient = this.buildClientFromConfig(
-    metrics,
-    ConnectionPool(
-        maxIdleConnections = 5, // The default from the no-arg ConnectionPool() constructor
-        keepAliveDuration = this.connectionIdleTimeout.inWholeMilliseconds,
-        timeUnit = TimeUnit.MILLISECONDS,
-        connectionListener = connectionListener ?: ConnectionListener.NONE,
-    ),
-)
-
 private fun minTlsConnectionSpec(tlsContext: TlsContext): ConnectionSpec {
     val minVersion = tlsContext.minVersion ?: TlsVersion.TLS_1_2
     val okHttpTlsVersions = SdkTlsVersion
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt
new file mode 100644
index 0000000000..c9acb07cef
--- /dev/null
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt
@@ -0,0 +1,281 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.http.engine.okhttp
+
+import okhttp3.*
+import java.io.Closeable
+import java.io.IOException
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.net.Proxy
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class EventListenerChainTest {
+    @Test
+    fun testForwardEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test forward events
+        chain.callStart(call)
+        chain.dnsStart(call, "example.com")
+        chain.proxySelectStart(call, createHttpUrl())
+
+        // Verify forward events were called in order (listener1 first, then listener2)
+        assertEquals("listener1:callStart", eventOrder[0])
+        assertEquals("listener2:callStart", eventOrder[1])
+        assertEquals("listener1:dnsStart", eventOrder[2])
+        assertEquals("listener2:dnsStart", eventOrder[3])
+        assertEquals("listener1:proxySelectStart", eventOrder[4])
+        assertEquals("listener2:proxySelectStart", eventOrder[5])
+    }
+
+    @Test
+    fun testReverseEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test reverse events
+        chain.dnsEnd(call, "example.com", listOf())
+        chain.proxySelectEnd(call, createHttpUrl(), listOf())
+        chain.callEnd(call)
+
+        // Verify reverse events were called in reverse order (listener2 first, then listener1)
+        assertEquals("listener2:dnsEnd", eventOrder[0])
+        assertEquals("listener1:dnsEnd", eventOrder[1])
+        assertEquals("listener2:proxySelectEnd", eventOrder[2])
+        assertEquals("listener1:proxySelectEnd", eventOrder[3])
+        assertEquals("listener2:callEnd", eventOrder[4])
+        assertEquals("listener1:callEnd", eventOrder[5])
+    }
+
+    @Test
+    fun testClose() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        // Close the chain
+        chain.close()
+
+        // Verify all listeners were closed
+        assertTrue(listener1.closed)
+        assertTrue(listener2.closed)
+    }
+
+    @Test
+    fun testMixedEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test mixed forward and reverse events
+        chain.callStart(call)
+        chain.dnsStart(call, "example.com")
+        chain.dnsEnd(call, "example.com", listOf())
+
+        // Verify the order of events
+        assertEquals("listener1:callStart", eventOrder[0]) // listener1 first (forward)
+        assertEquals("listener2:callStart", eventOrder[1]) // listener2 second (forward)
+        assertEquals("listener1:dnsStart", eventOrder[2]) // listener1 first (forward)
+        assertEquals("listener2:dnsStart", eventOrder[3]) // listener2 second (forward)
+        assertEquals("listener2:dnsEnd", eventOrder[4]) // listener2 first (reverse)
+        assertEquals("listener1:dnsEnd", eventOrder[5]) // listener1 second (reverse)
+
+        // Clear event order
+        eventOrder.clear()
+
+        // Test more events to verify the sequence
+        chain.requestHeadersStart(call) // forward event
+        chain.requestHeadersEnd(call, Request.Builder().url("https://example.com").build()) // reverse event
+        chain.responseHeadersStart(call) // forward event
+        chain.responseHeadersEnd(
+            call,
+            Response.Builder()
+                .request(Request.Builder().url("https://example.com").build())
+                .protocol(Protocol.HTTP_2)
+                .code(200)
+                .message("OK")
+                .build(),
+        ) // reverse event
+
+        // Verify the sequence of events
+        assertEquals("listener1:requestHeadersStart", eventOrder[0]) // listener1 first (forward)
+        assertEquals("listener2:requestHeadersStart", eventOrder[1]) // listener2 second (forward)
+        assertEquals("listener2:requestHeadersEnd", eventOrder[2]) // listener2 first (reverse)
+        assertEquals("listener1:requestHeadersEnd", eventOrder[3]) // listener1 second (reverse)
+        assertEquals("listener1:responseHeadersStart", eventOrder[4]) // listener1 first (forward)
+        assertEquals("listener2:responseHeadersStart", eventOrder[5]) // listener2 second (forward)
+        assertEquals("listener2:responseHeadersEnd", eventOrder[6]) // listener2 first (reverse)
+        assertEquals("listener1:responseHeadersEnd", eventOrder[7]) // listener1 second (reverse)
+    }
+
+    // A test EventListener that records the order of calls
+    private class TestEventListener(val name: String, val eventOrder: MutableList<String>) :
+        EventListener(),
+        Closeable {
+        var closed = false
+
+        override fun callStart(call: Call) {
+            eventOrder.add("$name:callStart")
+        }
+
+        override fun dnsStart(call: Call, domainName: String) {
+            eventOrder.add("$name:dnsStart")
+        }
+
+        override fun dnsEnd(call: Call, domainName: String, inetAddressList: List<InetAddress>) {
+            eventOrder.add("$name:dnsEnd")
+        }
+
+        override fun proxySelectStart(call: Call, url: HttpUrl) {
+            eventOrder.add("$name:proxySelectStart")
+        }
+
+        override fun proxySelectEnd(call: Call, url: HttpUrl, proxies: List<Proxy>) {
+            eventOrder.add("$name:proxySelectEnd")
+        }
+
+        override fun connectStart(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy) {
+            eventOrder.add("$name:connectStart")
+        }
+
+        override fun secureConnectStart(call: Call) {
+            eventOrder.add("$name:secureConnectStart")
+        }
+
+        override fun secureConnectEnd(call: Call, handshake: Handshake?) {
+            eventOrder.add("$name:secureConnectEnd")
+        }
+
+        override fun connectEnd(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?) {
+            eventOrder.add("$name:connectEnd")
+        }
+
+        override fun connectFailed(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?, ioe: IOException) {
+            eventOrder.add("$name:connectFailed")
+        }
+
+        override fun connectionAcquired(call: Call, connection: Connection) {
+            eventOrder.add("$name:connectionAcquired")
+        }
+
+        override fun connectionReleased(call: Call, connection: Connection) {
+            eventOrder.add("$name:connectionReleased")
+        }
+
+        override fun requestHeadersStart(call: Call) {
+            eventOrder.add("$name:requestHeadersStart")
+        }
+
+        override fun requestHeadersEnd(call: Call, request: Request) {
+            eventOrder.add("$name:requestHeadersEnd")
+        }
+
+        override fun requestBodyStart(call: Call) {
+            eventOrder.add("$name:requestBodyStart")
+        }
+
+        override fun requestBodyEnd(call: Call, byteCount: Long) {
+            eventOrder.add("$name:requestBodyEnd")
+        }
+
+        override fun requestFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:requestFailed")
+        }
+
+        override fun responseHeadersStart(call: Call) {
+            eventOrder.add("$name:responseHeadersStart")
+        }
+
+        override fun responseHeadersEnd(call: Call, response: Response) {
+            eventOrder.add("$name:responseHeadersEnd")
+        }
+
+        override fun responseBodyStart(call: Call) {
+            eventOrder.add("$name:responseBodyStart")
+        }
+
+        override fun responseBodyEnd(call: Call, byteCount: Long) {
+            eventOrder.add("$name:responseBodyEnd")
+        }
+
+        override fun responseFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:responseFailed")
+        }
+
+        override fun callEnd(call: Call) {
+            eventOrder.add("$name:callEnd")
+        }
+
+        override fun callFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:callFailed")
+        }
+
+        override fun canceled(call: Call) {
+            eventOrder.add("$name:canceled")
+        }
+
+        override fun satisfactionFailure(call: Call, response: Response) {
+            eventOrder.add("$name:satisfactionFailure")
+        }
+
+        override fun cacheConditionalHit(call: Call, cachedResponse: Response) {
+            eventOrder.add("$name:cacheConditionalHit")
+        }
+
+        override fun cacheHit(call: Call, response: Response) {
+            eventOrder.add("$name:cacheHit")
+        }
+
+        override fun cacheMiss(call: Call) {
+            eventOrder.add("$name:cacheMiss")
+        }
+
+        override fun close() {
+            closed = true
+        }
+    }
+
+    // Helper methods to create mock objects
+    private fun createMockCall(): Call = object : Call {
+        override fun cancel() {}
+        override fun clone(): Call = this
+        override fun enqueue(responseCallback: Callback) {}
+        override fun execute(): Response = throw UnsupportedOperationException()
+        override fun isCanceled(): Boolean = false
+        override fun isExecuted(): Boolean = false
+        override fun request(): Request = Request.Builder().url("https://example.com").build()
+        override fun timeout(): okio.Timeout = okio.Timeout()
+    }
+
+    private fun createHttpUrl(): HttpUrl = HttpUrl.Builder()
+        .scheme("https")
+        .host("example.com")
+        .build()
+}
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp4/README.md b/runtime/protocol/http-client-engines/http-client-engine-okhttp4/README.md
index 0f7077a217..7d3e12bba3 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp4/README.md
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp4/README.md
@@ -1,19 +1,13 @@
 # OkHttp4 Engine
 
-The AWS SDK for Kotlin depends on OkHttp **5.0.0-alpha.x**, which despite being in alpha, is claimed to be production stable and safe for consumption:
+The AWS SDK for Kotlin depends on a stable version of OkHttp **5.x**.
 
-> Although this release is labeled alpha, the only unstable thing in it is our new APIs. 
-> This release has many critical bug fixes and is safe to run in production. 
-> We’re eager to stabilize our new APIs so we can get out of alpha.
-> 
-> https://square.github.io/okhttp/changelogs/changelog/#version-500-alpha12
-
-This `OkHttp4Engine` is intended to be used for applications which still depend on okhttp3 **4.x** and can't upgrade to the newest alpha version.
+This `OkHttp4Engine` is intended to be used by applications which still depend on okhttp3 **4.x** and can't upgrade to the next major version.
 
 ## Configuration
 
 ### Gradle
-Because the SDK's default HTTP engine depends on okhttp3 **5.0.0-alpha.X**, consumers will need to force Gradle to resolve to **4.x** to prevent the alpha dependency from being introduced transitively. Here is a sample configuration:
+Because the SDK's default HTTP engine depends on okhttp3 **5.x**, consumers will need to force Gradle to resolve to **4.x** to prevent the newer dependency from being introduced transitively. Here is a sample configuration:
 ```kts
 dependencies {
     implementation("aws.sdk.kotlin:s3:$SDK_VERSION") // and any other AWS SDK clients... 
@@ -25,7 +19,7 @@ configurations.all {
         // Force resolve to OkHttp 4.x
         force("com.squareup.okhttp3:okhttp:4.12.0") // or whichever version you are using... 
     }
-    exclude(group = "com.squareup.okhttp3", module = "okhttp-coroutines") // Exclude dependency on okhttp-coroutines, which is introduced in 5.0.0-alpha.X 
+    exclude(group = "com.squareup.okhttp3", module = "okhttp-coroutines") // Exclude dependency on okhttp-coroutines, which was introduced in 5.0.0-alpha.X 
 }
 ```
 
@@ -86,6 +80,17 @@ Caused by: java.lang.ClassNotFoundException: okhttp3.coroutines.ExecuteAsyncKt
 	... 9 more
 ```
 
-It likely means you failed to configure the SDK client to use the `OkHttpEngine4`. 
-Please double-check all of your SDK client configurations to ensure `httpClient = OkHttpEngine4()` is configured,
-and if the problem persists, [open an issue](https://github.com/smithy-lang/smithy-kotlin/issues/new/choose).
\ No newline at end of file
+It likely means you failed to configure the SDK client to use the `OkHttp4Engine`. 
+Please double-check all of your SDK client configurations to ensure `httpClient = OkHttp4Engine()` is configured,
+and if the problem persists, [open an issue](https://github.com/smithy-lang/smithy-kotlin/issues/new/choose).
+
+### Android R8 / ProGuard Configuration
+If you're using the OkHttp4Engine in an Android application with R8 or Proguard for code minification, and you see an error similar to the following:
+```
+ERROR: R8: Missing class okhttp3.coroutines.ExecuteAsyncKt (referenced from: java.lang.Object aws.smithy.kotlin.runtime.http.engine.okhttp.OkHttpEngine.roundTrip(aws.smithy.kotlin.runtime.operation.ExecutionContext, aws.smithy.kotlin.runtime.http.request.HttpRequest, kotlin.coroutines.Continuation))
+```
+
+You'll need to add the following rule to either `proguard-rules.pro` or `consumer-rules.pro`, depending on your project structure:
+```
+-dontwarn okhttp3.coroutines.ExecuteAsyncKt
+```
diff --git a/runtime/protocol/http-client-engines/test-suite/build.gradle.kts b/runtime/protocol/http-client-engines/test-suite/build.gradle.kts
index 065872fe7a..3f0d75176b 100644
--- a/runtime/protocol/http-client-engines/test-suite/build.gradle.kts
+++ b/runtime/protocol/http-client-engines/test-suite/build.gradle.kts
@@ -46,12 +46,6 @@ kotlin {
         jvmTest {
             dependencies {
                 implementation(libs.docker.core)
-                // FIXME docker-java has a ton of dependencies with vulnerabilities, and they don't seem motivated to fix them.
-                // So we must override their dependencies with the latest patched versions. https://github.com/docker-java/docker-java/issues/1974
-                implementation("com.fasterxml.jackson.core:jackson-databind:2.12.7.1") // https://github.com/docker-java/docker-java/issues/2177
-                implementation("org.apache.commons:commons-compress:1.26.0") // https://github.com/docker-java/docker-java/pull/2256
-                implementation("org.bouncycastle:bcpkix-jdk18on:1.78") // https://github.com/docker-java/docker-java/pull/2326
-
                 implementation(libs.docker.transport.zerodep)
 
                 implementation(project(":runtime:observability:telemetry-defaults"))
diff --git a/runtime/protocol/http-client/api/http-client.api b/runtime/protocol/http-client/api/http-client.api
index 9a752b6788..ecfd153135 100644
--- a/runtime/protocol/http-client/api/http-client.api
+++ b/runtime/protocol/http-client/api/http-client.api
@@ -29,6 +29,8 @@ public abstract interface class aws/smithy/kotlin/runtime/http/config/HttpEngine
 	public abstract fun getHttpClient ()Laws/smithy/kotlin/runtime/http/engine/HttpClientEngine;
 	public abstract fun httpClient (Laws/smithy/kotlin/runtime/http/config/EngineFactory;Lkotlin/jvm/functions/Function1;)V
 	public abstract fun httpClient (Lkotlin/jvm/functions/Function1;)V
+	public static synthetic fun httpClient$default (Laws/smithy/kotlin/runtime/http/config/HttpEngineConfig$Builder;Laws/smithy/kotlin/runtime/http/config/EngineFactory;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
+	public static synthetic fun httpClient$default (Laws/smithy/kotlin/runtime/http/config/HttpEngineConfig$Builder;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public abstract fun setHttpClient (Laws/smithy/kotlin/runtime/http/engine/HttpClientEngine;)V
 }
 
@@ -40,6 +42,18 @@ public final class aws/smithy/kotlin/runtime/http/config/HttpEngineConfig$Builde
 public abstract interface annotation class aws/smithy/kotlin/runtime/http/config/HttpEngineConfigDsl : java/lang/annotation/Annotation {
 }
 
+public abstract interface class aws/smithy/kotlin/runtime/http/config/TimeoutConfig {
+	public abstract fun getAttemptTimeout-FghU774 ()Lkotlin/time/Duration;
+	public abstract fun getCallTimeout-FghU774 ()Lkotlin/time/Duration;
+}
+
+public abstract interface class aws/smithy/kotlin/runtime/http/config/TimeoutConfig$Builder {
+	public abstract fun getAttemptTimeout-FghU774 ()Lkotlin/time/Duration;
+	public abstract fun getCallTimeout-FghU774 ()Lkotlin/time/Duration;
+	public abstract fun setAttemptTimeout-BwNAW2A (Lkotlin/time/Duration;)V
+	public abstract fun setCallTimeout-BwNAW2A (Lkotlin/time/Duration;)V
+}
+
 public final class aws/smithy/kotlin/runtime/http/engine/AlpnId : java/lang/Enum {
 	public static final field H2_PRIOR_KNOWLEDGE Laws/smithy/kotlin/runtime/http/engine/AlpnId;
 	public static final field HTTP1_1 Laws/smithy/kotlin/runtime/http/engine/AlpnId;
@@ -309,7 +323,7 @@ public final class aws/smithy/kotlin/runtime/http/interceptors/ContinueIntercept
 }
 
 public final class aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor : aws/smithy/kotlin/runtime/client/Interceptor {
-	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;)V
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function2;)V
 	public fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -487,19 +501,33 @@ public final class aws/smithy/kotlin/runtime/http/middleware/MutateHeaders : aws
 	public final fun setIfMissing (Ljava/lang/String;Ljava/lang/String;)V
 }
 
+public final class aws/smithy/kotlin/runtime/http/operation/AttemptTimeoutException : aws/smithy/kotlin/runtime/http/operation/ClientTimeoutException {
+	public fun <init> (Ljava/lang/String;Ljava/lang/Throwable;)V
+}
+
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/AuthSchemeResolver {
 	public abstract fun resolve (Laws/smithy/kotlin/runtime/http/operation/OperationRequest;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
+public final class aws/smithy/kotlin/runtime/http/operation/CallTimeoutException : aws/smithy/kotlin/runtime/http/operation/ClientTimeoutException {
+	public fun <init> (Ljava/lang/String;Ljava/lang/Throwable;)V
+}
+
+public abstract class aws/smithy/kotlin/runtime/http/operation/ClientTimeoutException : aws/smithy/kotlin/runtime/ClientException {
+	public fun <init> (Ljava/lang/String;Ljava/lang/Throwable;Z)V
+}
+
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/EndpointResolver {
 	public abstract fun resolve (Laws/smithy/kotlin/runtime/http/operation/ResolveEndpointRequest;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public abstract fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
+	public static final field Companion Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer$Companion;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
+public final class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer$Companion {
+	public final fun getIdentity ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
+	public final fun getUnit ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer$NonStreaming : aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
@@ -512,6 +540,8 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDes
 
 public final class aws/smithy/kotlin/runtime/http/operation/HttpOperationContext {
 	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/HttpOperationContext;
+	public final fun getAttemptTimeout ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
+	public final fun getCallTimeout ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
 	public final fun getClockSkew ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
 	public final fun getClockSkewApproximateSigningTime ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
 	public final fun getDefaultChecksumAlgorithm ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
@@ -523,11 +553,12 @@ public final class aws/smithy/kotlin/runtime/http/operation/HttpOperationContext
 	public final fun getSdkInvocationId ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerialize {
-	public abstract fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
+	public static final field Companion Laws/smithy/kotlin/runtime/http/operation/HttpSerializer$Companion;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
+public final class aws/smithy/kotlin/runtime/http/operation/HttpSerializer$Companion {
+	public final fun getUnit ()Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer$NonStreaming : aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
@@ -538,13 +569,8 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSer
 	public abstract fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public final class aws/smithy/kotlin/runtime/http/operation/IdentityDeserializer : aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/IdentityDeserializer;
-	public fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/InitializeMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/InitializeMiddleware$DefaultImpls {
@@ -556,7 +582,7 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/InlineM
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddleware : aws/smithy/kotlin/runtime/io/middleware/ModifyRequest {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddleware$DefaultImpls {
@@ -564,7 +590,7 @@ public final class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddlew
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/MutateMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/MutateMiddleware$DefaultImpls {
@@ -633,7 +659,7 @@ public final class aws/smithy/kotlin/runtime/http/operation/OperationTelemetryKt
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/ReceiveMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/ReceiveMiddleware$DefaultImpls {
@@ -675,20 +701,16 @@ public final class aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationBuil
 	public final fun build ()Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;
 	public final fun getContext ()Laws/smithy/kotlin/runtime/operation/ExecutionContext;
 	public final fun getDeserializeWith ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
-	public final fun getDeserializer ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserialize;
 	public final fun getExecution ()Laws/smithy/kotlin/runtime/http/operation/SdkOperationExecution;
 	public final fun getHostPrefix ()Ljava/lang/String;
 	public final fun getOperationName ()Ljava/lang/String;
 	public final fun getSerializeWith ()Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;
-	public final fun getSerializer ()Laws/smithy/kotlin/runtime/http/operation/HttpSerialize;
 	public final fun getServiceName ()Ljava/lang/String;
 	public final fun getTelemetry ()Laws/smithy/kotlin/runtime/http/operation/SdkOperationTelemetry;
 	public final fun setDeserializeWith (Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;)V
-	public final fun setDeserializer (Laws/smithy/kotlin/runtime/http/operation/HttpDeserialize;)V
 	public final fun setHostPrefix (Ljava/lang/String;)V
 	public final fun setOperationName (Ljava/lang/String;)V
 	public final fun setSerializeWith (Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;)V
-	public final fun setSerializer (Laws/smithy/kotlin/runtime/http/operation/HttpSerialize;)V
 	public final fun setServiceName (Ljava/lang/String;)V
 }
 
@@ -731,14 +753,3 @@ public final class aws/smithy/kotlin/runtime/http/operation/SdkOperationTelemetr
 	public final fun setSpanName (Ljava/lang/String;)V
 }
 
-public final class aws/smithy/kotlin/runtime/http/operation/UnitDeserializer : aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/UnitDeserializer;
-	public fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
-public final class aws/smithy/kotlin/runtime/http/operation/UnitSerializer : aws/smithy/kotlin/runtime/http/operation/HttpSerialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/UnitSerializer;
-	public synthetic fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Lkotlin/Unit;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/config/TimeoutConfig.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/config/TimeoutConfig.kt
new file mode 100644
index 0000000000..25bc7db84d
--- /dev/null
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/config/TimeoutConfig.kt
@@ -0,0 +1,39 @@
+package aws.smithy.kotlin.runtime.http.config
+
+import kotlin.time.Duration
+
+/**
+ * Defines optional timeout configuration for clients.
+ */
+public interface TimeoutConfig {
+    /**
+     * The maximum amount of time to wait for any single attempt of a request within the retry loop. By default, the
+     * value is `null` indicating no timeout is enforced. Attempt timeouts may be retried if allowed by the current
+     * retry policy and retry capacity.
+     */
+    public val attemptTimeout: Duration?
+
+    /**
+     * The maximum amount of time to wait for completion of a call, including any retries after the first attempt. By
+     * default, the value is `null` indicating no timeout is enforced. Call timeouts are not retried.
+     */
+    public val callTimeout: Duration?
+
+    /**
+     * A mutable instance used to set timeout configuration for clients.
+     */
+    public interface Builder {
+        /**
+         * The maximum amount of time to wait for any single attempt of a request within the retry loop. By default, the
+         * value is `null` indicating no timeout is enforced. Attempt timeouts may be retried if allowed by the current
+         * retry policy and retry capacity.
+         */
+        public var attemptTimeout: Duration?
+
+        /**
+         * The maximum amount of time to wait for completion of a call, including any retries after the first attempt.
+         * By default, the value is `null` indicating no timeout is enforced. Call timeouts are not retried.
+         */
+        public var callTimeout: Duration?
+    }
+}
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/engine/HttpClientEngine.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/engine/HttpClientEngine.kt
index 854ee44b67..48ee017edd 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/engine/HttpClientEngine.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/engine/HttpClientEngine.kt
@@ -13,6 +13,7 @@ import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import kotlinx.atomicfu.atomic
 import kotlinx.coroutines.*
 import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
 
 /**
  * Functionality a real HTTP client must provide.
@@ -39,12 +40,24 @@ public interface CloseableHttpClientEngine :
     Closeable
 
 /**
- * Base class that SDK [HttpClientEngine]s SHOULD inherit from rather than implementing directly.
+ * Base class that SDK [HttpClientEngine]s SHOULD inherit from rather than implementing directly. This class's
+ * [CoroutineContext] will include [SupervisorJob] because the failure of individual requests should not affect other
+ * requests or the overall engine.
  */
 @InternalApi
-public abstract class HttpClientEngineBase(engineName: String) : CloseableHttpClientEngine {
-    // why SupervisorJob? because failure of individual requests should not affect other requests or the overall engine
-    override val coroutineContext: CoroutineContext = SupervisorJob() + CoroutineName("http-client-engine-$engineName-context")
+public abstract class HttpClientEngineBase private constructor(
+    override val coroutineContext: CoroutineContext,
+) : CloseableHttpClientEngine {
+    public constructor(engineName: String) : this(engineName, EmptyCoroutineContext)
+
+    /**
+     * Initializes a new [HttpClientEngineBase]. This internal overload allows setting a base [CoroutineContext] which
+     * is useful in tests using `runTest` (otherwise the base context will be empty and so will default to using
+     * [Dispatchers.Default]).
+     */
+    internal constructor(engineName: String, baseContext: CoroutineContext) :
+        this(baseContext + SupervisorJob() + CoroutineName("http-client-engine-$engineName-context"))
+
     private val closed = atomic(false)
 
     final override fun close() {
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
index ce1ef41857..adb4babd48 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
@@ -23,7 +23,7 @@ import kotlin.reflect.KClass
 @InternalApi
 public class DiscoveredEndpointErrorInterceptor(
     private val errorType: KClass<out ServiceException>,
-    private val invalidate: (ExecutionContext) -> Unit,
+    private val invalidate: suspend (ExecutionContext) -> Unit,
 ) : HttpInterceptor {
     override suspend fun modifyBeforeAttemptCompletion(
         context: ResponseInterceptorContext<Any, Any, HttpRequest, HttpResponse?>,
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/middleware/RetryMiddleware.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/middleware/RetryMiddleware.kt
index 7b8144c82e..cb865caa10 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/middleware/RetryMiddleware.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/middleware/RetryMiddleware.kt
@@ -9,7 +9,6 @@ import aws.smithy.kotlin.runtime.businessmetrics.SmithyBusinessMetric
 import aws.smithy.kotlin.runtime.businessmetrics.emitBusinessMetric
 import aws.smithy.kotlin.runtime.http.interceptors.InterceptorExecutor
 import aws.smithy.kotlin.runtime.http.operation.*
-import aws.smithy.kotlin.runtime.http.operation.deepCopy
 import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
 import aws.smithy.kotlin.runtime.http.request.immutableView
 import aws.smithy.kotlin.runtime.http.request.toBuilder
@@ -84,7 +83,10 @@ internal class RetryMiddleware<I, O>(
     ): Result<O> {
         val result = interceptors.readBeforeAttempt(request.subject.immutableView())
             .mapCatching {
-                next.call(request)
+                val attemptTimeout = request.context.getOrNull(HttpOperationContext.AttemptTimeout)
+                scopedTimeout(TimeoutScope.Attempt(attempt), attemptTimeout) {
+                    next.call(request)
+                }
             }
 
         // get the http call for this attempt (if we made it that far)
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpOperationContext.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpOperationContext.kt
index 56444dca98..9078b50aaa 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpOperationContext.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpOperationContext.kt
@@ -19,6 +19,15 @@ import kotlin.time.Duration
  */
 @InternalApi
 public object HttpOperationContext {
+    /**
+     * The amount of time to wait for a single attempt to complete
+     */
+    public val AttemptTimeout: AttributeKey<Duration> = AttributeKey("aws.smithy.kotlin#AttemptDuration")
+
+    /**
+     * The amount of time to wait for a call to complete, including any retries
+     */
+    public val CallTimeout: AttributeKey<Duration> = AttributeKey("aws.smithy.kotlin#CallDuration")
 
     /**
      * A prefix to prepend the resolved hostname with.
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
index 5e50a3cca9..b50a05d037 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
@@ -15,6 +15,13 @@ import aws.smithy.kotlin.runtime.operation.ExecutionContext
  */
 @InternalApi
 public sealed interface HttpSerializer<T> {
+    @InternalApi
+    public companion object {
+        public val Unit: HttpSerializer<Unit> = object : NonStreaming<Unit> {
+            override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
+                HttpRequestBuilder()
+        }
+    }
 
     /**
      * Serializer for streaming operations that need full control over serialization of the body
@@ -38,6 +45,17 @@ public sealed interface HttpSerializer<T> {
  */
 @InternalApi
 public sealed interface HttpDeserializer<T> {
+    @InternalApi
+    public companion object {
+        public val Identity: HttpDeserializer<HttpResponse> = object : NonStreaming<HttpResponse> {
+            override fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?): HttpResponse =
+                call.response
+        }
+
+        public val Unit: HttpDeserializer<Unit> = object : NonStreaming<Unit> {
+            override fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?) { }
+        }
+    }
 
     /**
      * Deserializer for streaming operations that need full control over deserialization of the body
@@ -56,66 +74,3 @@ public sealed interface HttpDeserializer<T> {
         public fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?): T
     }
 }
-
-/**
- * Implemented by types that know how to serialize to the HTTP protocol.
- */
-@Deprecated("use HttpSerializer.Streaming")
-@InternalApi
-public fun interface HttpSerialize<T> {
-    public suspend fun serialize(context: ExecutionContext, input: T): HttpRequestBuilder
-}
-
-@Suppress("DEPRECATION")
-private class LegacyHttpSerializeAdapter<T>(val serializer: HttpSerialize<T>) : HttpSerializer.Streaming<T> {
-    override suspend fun serialize(context: ExecutionContext, input: T): HttpRequestBuilder =
-        serializer.serialize(context, input)
-}
-
-@Suppress("DEPRECATION")
-internal fun <T> HttpSerialize<T>.intoSerializer(): HttpSerializer<T> = LegacyHttpSerializeAdapter(this)
-
-/**
- * Implemented by types that know how to deserialize from the HTTP protocol.
- */
-@Deprecated("use HttpDeserializer.Streaming")
-@InternalApi
-public fun interface HttpDeserialize<T> {
-    public suspend fun deserialize(context: ExecutionContext, call: HttpCall): T
-}
-
-@Suppress("DEPRECATION")
-private class LegacyHttpDeserializeAdapter<T>(val deserializer: HttpDeserialize<T>) : HttpDeserializer.Streaming<T> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall): T =
-        deserializer.deserialize(context, call)
-}
-
-@Suppress("DEPRECATION")
-internal fun <T> HttpDeserialize<T>.intoDeserializer(): HttpDeserializer<T> = LegacyHttpDeserializeAdapter(this)
-
-/**
- * Convenience deserialize implementation for a type with no output type
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object UnitDeserializer : HttpDeserialize<Unit> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall) {}
-}
-
-/**
- * Convenience serialize implementation for a type with no input type
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object UnitSerializer : HttpSerialize<Unit> {
-    override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder = HttpRequestBuilder()
-}
-
-/**
- * Convenience deserialize implementation that returns the response without modification
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object IdentityDeserializer : HttpDeserialize<HttpResponse> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall): HttpResponse = call.response
-}
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
index 775da6c891..abb3b8cc46 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
@@ -36,17 +36,6 @@ public class SdkHttpOperation<I, O> internal constructor(
     internal val typeInfo: OperationTypeInfo,
     internal val telemetry: SdkOperationTelemetry,
 ) {
-
-    @Suppress("DEPRECATION")
-    internal constructor(
-        execution: SdkOperationExecution<I, O>,
-        context: ExecutionContext,
-        serializer: HttpSerialize<I>,
-        deserializer: HttpDeserialize<O>,
-        typeInfo: OperationTypeInfo,
-        telemetry: SdkOperationTelemetry,
-    ) : this(execution, context, serializer.intoSerializer(), deserializer.intoDeserializer(), typeInfo, telemetry)
-
     init {
         context[HttpOperationContext.SdkInvocationId] = Uuid.random().toString()
     }
@@ -142,27 +131,8 @@ public class SdkHttpOperationBuilder<I, O>(
     private val outputType: KClass<*>,
 ) {
     public val telemetry: SdkOperationTelemetry = SdkOperationTelemetry()
-
-    @Suppress("DEPRECATION")
-    @Deprecated("use serializeWith")
-    public var serializer: HttpSerialize<I>? = null
-        set(value) {
-            field = value
-            serializeWith = value?.intoSerializer()
-        }
-
     public var serializeWith: HttpSerializer<I>? = null
-
-    @Suppress("DEPRECATION")
-    @Deprecated("use deserializeWith")
-    public var deserializer: HttpDeserialize<O>? = null
-        set(value) {
-            field = value
-            deserializeWith = value?.intoDeserializer()
-        }
-
     public var deserializeWith: HttpDeserializer<O>? = null
-
     public val execution: SdkOperationExecution<I, O> = SdkOperationExecution()
     public val context: ExecutionContext = ExecutionContext()
 
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecution.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecution.kt
index d30c7c546b..2384e508b3 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecution.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecution.kt
@@ -15,10 +15,13 @@ import aws.smithy.kotlin.runtime.client.logMode
 import aws.smithy.kotlin.runtime.collections.attributesOf
 import aws.smithy.kotlin.runtime.collections.emptyAttributes
 import aws.smithy.kotlin.runtime.collections.merge
-import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.HttpCall
+import aws.smithy.kotlin.runtime.http.HttpHandler
 import aws.smithy.kotlin.runtime.http.auth.SignHttpRequest
+import aws.smithy.kotlin.runtime.http.complete
 import aws.smithy.kotlin.runtime.http.interceptors.InterceptorExecutor
 import aws.smithy.kotlin.runtime.http.middleware.RetryMiddleware
+import aws.smithy.kotlin.runtime.http.readAll
 import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
 import aws.smithy.kotlin.runtime.http.request.dumpRequest
 import aws.smithy.kotlin.runtime.http.request.immutableView
@@ -193,8 +196,6 @@ private fun <I, O> HttpDeserializer<O>.decorate(
     interceptors: InterceptorExecutor<I, O>,
 ): Handler<SdkHttpRequest, O> = DeserializeHandler(inner, this, interceptors)
 
-// internal glue used to marry one phase to another
-
 /**
  * Outermost handler that wraps the entire middleware pipeline and handles interceptor hooks related
  * to the start/end of an operation
@@ -207,7 +208,10 @@ private class OperationHandler<Input, Output>(
         coroutineContext.trace<OperationHandler<*, *>> { "operation started" }
         val result = interceptors.readBeforeExecution(request.subject)
             .mapCatching {
-                inner.call(request)
+                val callTimeout = request.context.getOrNull(HttpOperationContext.CallTimeout)
+                scopedTimeout(TimeoutScope.Call, callTimeout) {
+                    inner.call(request)
+                }
             }
             .let {
                 interceptors.modifyBeforeCompletion(it)
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/Timeouts.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/Timeouts.kt
new file mode 100644
index 0000000000..a805e45017
--- /dev/null
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/Timeouts.kt
@@ -0,0 +1,71 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.http.operation
+
+import aws.smithy.kotlin.runtime.ClientException
+import aws.smithy.kotlin.runtime.ErrorMetadata
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.withTimeout
+import kotlin.time.Duration
+
+internal sealed interface TimeoutScope {
+    val description: String
+
+    data object Call : TimeoutScope {
+        override val description = "Call"
+    }
+
+    data class Attempt(val attempt: Int) : TimeoutScope {
+        override val description = "Attempt #$attempt"
+    }
+}
+
+/**
+ * Indicates that a client-side configured timeout was exceeded (e.g., call timeout, attempt timeout, etc.)
+ */
+public abstract class ClientTimeoutException(
+    message: String,
+    cause: Throwable,
+    retryable: Boolean,
+) : ClientException(message, cause) {
+    init {
+        sdkErrorMetadata.attributes[ErrorMetadata.Retryable] = retryable
+    }
+}
+
+/**
+ * Indicates that a single attempt took longer than allowed to complete
+ */
+public class AttemptTimeoutException(message: String, cause: Throwable) : ClientTimeoutException(message, cause, true)
+
+/**
+ * Indicates that a call (including any retry attempts) took longer than allowed to complete
+ */
+public class CallTimeoutException(message: String, cause: Throwable) : ClientTimeoutException(message, cause, false)
+
+internal suspend inline fun <T> scopedTimeout(
+    scope: TimeoutScope,
+    duration: Duration?,
+    crossinline block: suspend () -> T,
+): T = when (duration) {
+    null -> block()
+    else ->
+        try {
+            withTimeout(duration) { block() }
+        } catch (e: TimeoutCancellationException) {
+            val message = buildString {
+                append(scope.description)
+                append(" exceeded configured timeout of ")
+                append(duration)
+            }
+
+            val exceptionType: (String, Throwable) -> Throwable = when (scope) {
+                is TimeoutScope.Attempt -> ::AttemptTimeoutException
+                TimeoutScope.Call -> ::CallTimeoutException
+            }
+
+            throw exceptionType(message, e)
+        }
+}
diff --git a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
index 22e36d1cf1..e564bedcc2 100644
--- a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
+++ b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
@@ -36,8 +36,8 @@ class SdkHttpOperationTest {
         val ex = assertFailsWith<IllegalArgumentException> {
             @Suppress("DEPRECATION")
             SdkHttpOperation.build<Unit, Unit> {
-                serializer = UnitSerializer
-                deserializer = UnitDeserializer
+                serializeWith = HttpSerializer.Unit
+                deserializeWith = HttpDeserializer.Unit
             }
         }
 
diff --git a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecutionTest.kt b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecutionTest.kt
index 11657db007..e0fc1b0289 100644
--- a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecutionTest.kt
+++ b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkOperationExecutionTest.kt
@@ -6,12 +6,11 @@
 package aws.smithy.kotlin.runtime.http.operation
 
 import aws.smithy.kotlin.runtime.auth.AuthSchemeId
-import aws.smithy.kotlin.runtime.http.Headers
-import aws.smithy.kotlin.runtime.http.HttpBody
-import aws.smithy.kotlin.runtime.http.HttpCall
-import aws.smithy.kotlin.runtime.http.HttpStatusCode
-import aws.smithy.kotlin.runtime.http.SdkHttpClient
-import aws.smithy.kotlin.runtime.http.auth.*
+import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.auth.AnonymousIdentityProvider
+import aws.smithy.kotlin.runtime.http.auth.AuthScheme
+import aws.smithy.kotlin.runtime.http.auth.HttpSigner
+import aws.smithy.kotlin.runtime.http.auth.SignHttpRequest
 import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineBase
 import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineConfig
 import aws.smithy.kotlin.runtime.http.request.HttpRequest
@@ -20,13 +19,74 @@ import aws.smithy.kotlin.runtime.http.response.HttpResponse
 import aws.smithy.kotlin.runtime.identity.asIdentityProviderConfig
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import aws.smithy.kotlin.runtime.time.Instant
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.test.runTest
-import kotlin.test.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertFalse
-import kotlin.test.assertTrue
+import kotlin.coroutines.CoroutineContext
+import kotlin.test.*
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.milliseconds
 
 class SdkOperationExecutionTest {
+    @Test
+    fun testAttemptTimeoutWithLongCall(): Unit = runTest {
+        val serialized = HttpRequestBuilder()
+        val op = newTestOperation<Unit, Unit>(serialized, Unit).apply {
+            context[HttpOperationContext.AttemptTimeout] = 200.milliseconds
+        }
+
+        val engine = DelayingHttpEngine(listOf(300.milliseconds, 300.milliseconds, 100.milliseconds))
+        val client = SdkHttpClient(engine)
+
+        val result = op.roundTrip(client, Unit)
+        assertEquals(Unit, result)
+        assertEquals(3, engine.callCount)
+    }
+
+    @Test
+    fun testAttemptTimeoutWithShortCall(): Unit = runTest {
+        val serialized = HttpRequestBuilder()
+        val op = newTestOperation<Unit, Unit>(serialized, Unit).apply {
+            context[HttpOperationContext.AttemptTimeout] = 300.milliseconds
+        }
+
+        val engine = DelayingHttpEngine(200.milliseconds)
+        val client = SdkHttpClient(engine)
+
+        val result = op.roundTrip(client, Unit)
+        assertEquals(Unit, result)
+        assertEquals(1, engine.callCount)
+    }
+
+    @Test
+    fun testCallTimeoutWithLongCall(): Unit = runTest {
+        val serialized = HttpRequestBuilder()
+        val op = newTestOperation<Unit, Unit>(serialized, Unit).apply {
+            context[HttpOperationContext.CallTimeout] = 200.milliseconds
+        }
+
+        val engine = DelayingHttpEngine(300.milliseconds)
+        val client = SdkHttpClient(engine)
+
+        assertFailsWith<CallTimeoutException> { op.roundTrip(client, Unit) }
+        assertEquals(1, engine.callCount)
+    }
+
+    @Test
+    fun testCallTimeoutWithShortCall(): Unit = runTest {
+        val serialized = HttpRequestBuilder()
+        val op = newTestOperation<Unit, Unit>(serialized, Unit).apply {
+            context[HttpOperationContext.CallTimeout] = 300.milliseconds
+        }
+
+        val engine = DelayingHttpEngine(200.milliseconds)
+        val client = SdkHttpClient(engine)
+
+        val result = op.roundTrip(client, Unit)
+        assertEquals(Unit, result)
+        assertEquals(1, engine.callCount)
+    }
+
     @Test
     fun testOperationMiddlewareOrder() = runTest {
         // sanity test middleware flows the way we expect
@@ -105,3 +165,32 @@ class SdkOperationExecutionTest {
         assertEquals(expectedOrder, actualOrder)
     }
 }
+
+private fun CoroutineScope.DelayingHttpEngine(duration: Duration) =
+    DelayingHttpEngine(coroutineContext, listOf(duration))
+
+private fun CoroutineScope.DelayingHttpEngine(durations: List<Duration>) =
+    DelayingHttpEngine(coroutineContext, durations)
+
+private class DelayingHttpEngine(
+    testContext: CoroutineContext,
+    durations: List<Duration>,
+) : HttpClientEngineBase("test engine", testContext) {
+    private val durations = run {
+        val terminator = durations.last()
+        val initial = durations.dropLast(1)
+        initial.asSequence() + generateSequence { terminator }
+    }.iterator()
+
+    var callCount = 0
+        private set
+
+    override val config: HttpClientEngineConfig = HttpClientEngineConfig.Default
+
+    override suspend fun roundTrip(context: ExecutionContext, request: HttpRequest): HttpCall {
+        callCount++
+        delay(durations.next())
+        val resp = HttpResponse(HttpStatusCode.OK, Headers.Empty, HttpBody.Empty)
+        return HttpCall(request, resp, Instant.now(), Instant.now())
+    }
+}
diff --git a/runtime/runtime-core/api/runtime-core.api b/runtime/runtime-core/api/runtime-core.api
index 0c7ba6d1cd..1ba5b08c40 100644
--- a/runtime/runtime-core/api/runtime-core.api
+++ b/runtime/runtime-core/api/runtime-core.api
@@ -180,6 +180,12 @@ public final class aws/smithy/kotlin/runtime/collections/CollectionExtKt {
 	public static final fun createOrAppend (Ljava/util/List;Ljava/lang/Object;)Ljava/util/List;
 }
 
+public abstract interface class aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache {
+	public abstract fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public abstract fun getSize ()I
+	public abstract fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
 public final class aws/smithy/kotlin/runtime/collections/LruCache {
 	public fun <init> (I)V
 	public final fun get (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -191,9 +197,9 @@ public final class aws/smithy/kotlin/runtime/collections/LruCache {
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/collections/MultiMap : java/util/Map, kotlin/jvm/internal/markers/KMappedMarker {
-	public abstract fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
+	public fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun getEntryValues ()Lkotlin/sequences/Sequence;
-	public abstract fun toMutableMultiMap ()Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
+	public fun toMutableMultiMap ()Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/MultiMap$DefaultImpls {
@@ -216,15 +222,15 @@ public abstract interface class aws/smithy/kotlin/runtime/collections/MutableMul
 	public abstract fun add (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun addAll (Ljava/lang/Object;ILjava/util/Collection;)Z
 	public abstract fun addAll (Ljava/lang/Object;Ljava/util/Collection;)Z
-	public abstract fun addAll (Ljava/util/Map;)V
-	public abstract fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
+	public fun addAll (Ljava/util/Map;)V
+	public fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun getEntryValues ()Lkotlin/sequences/Sequence;
-	public abstract fun put (Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/List;
+	public fun put (Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/List;
 	public abstract fun removeAll (Ljava/lang/Object;Ljava/util/Collection;)Ljava/lang/Boolean;
 	public abstract fun removeAt (Ljava/lang/Object;I)Ljava/lang/Object;
 	public abstract fun removeElement (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun retainAll (Ljava/lang/Object;Ljava/util/Collection;)Ljava/lang/Boolean;
-	public abstract fun toMultiMap ()Laws/smithy/kotlin/runtime/collections/MultiMap;
+	public fun toMultiMap ()Laws/smithy/kotlin/runtime/collections/MultiMap;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/MutableMultiMap$DefaultImpls {
@@ -238,12 +244,12 @@ public final class aws/smithy/kotlin/runtime/collections/MutableMultiMapKt {
 	public static final fun mutableMultiMapOf ([Lkotlin/Pair;)Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
 }
 
-public final class aws/smithy/kotlin/runtime/collections/ReadThroughCache {
+public final class aws/smithy/kotlin/runtime/collections/PeriodicSweepCache : aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache {
 	public synthetic fun <init> (JLaws/smithy/kotlin/runtime/time/Clock;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public synthetic fun <init> (JLaws/smithy/kotlin/runtime/time/Clock;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public final fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public final fun getSize ()I
-	public final fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun getSize ()I
+	public fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/StackKt {
@@ -257,10 +263,10 @@ public final class aws/smithy/kotlin/runtime/collections/StackKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/collections/ValuesMap {
 	public abstract fun contains (Ljava/lang/String;)Z
-	public abstract fun contains (Ljava/lang/String;Ljava/lang/Object;)Z
+	public fun contains (Ljava/lang/String;Ljava/lang/Object;)Z
 	public abstract fun entries ()Ljava/util/Set;
-	public abstract fun forEach (Lkotlin/jvm/functions/Function2;)V
-	public abstract fun get (Ljava/lang/String;)Ljava/lang/Object;
+	public fun forEach (Lkotlin/jvm/functions/Function2;)V
+	public fun get (Ljava/lang/String;)Ljava/lang/Object;
 	public abstract fun getAll (Ljava/lang/String;)Ljava/util/List;
 	public abstract fun getCaseInsensitiveName ()Z
 	public abstract fun isEmpty ()Z
@@ -721,6 +727,7 @@ public abstract interface class aws/smithy/kotlin/runtime/hashing/HashFunction {
 	public abstract fun getDigestSizeBytes ()I
 	public abstract fun reset ()V
 	public abstract fun update ([BII)V
+	public static synthetic fun update$default (Laws/smithy/kotlin/runtime/hashing/HashFunction;[BIIILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/hashing/HashFunction$DefaultImpls {
@@ -921,6 +928,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSink : a
 	public abstract fun getBuffer ()Laws/smithy/kotlin/runtime/io/SdkBuffer;
 	public abstract fun write (Laws/smithy/kotlin/runtime/io/SdkSource;J)V
 	public abstract fun write ([BII)V
+	public static synthetic fun write$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSink;[BIIILjava/lang/Object;)V
 	public abstract fun writeAll (Laws/smithy/kotlin/runtime/io/SdkSource;)J
 	public abstract fun writeByte (B)V
 	public abstract fun writeInt (I)V
@@ -930,6 +938,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSink : a
 	public abstract fun writeShort (S)V
 	public abstract fun writeShortLe (S)V
 	public abstract fun writeUtf8 (Ljava/lang/String;II)V
+	public static synthetic fun writeUtf8$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSink;Ljava/lang/String;IIILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkBufferedSink$DefaultImpls {
@@ -942,6 +951,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSource :
 	public abstract fun getBuffer ()Laws/smithy/kotlin/runtime/io/SdkBuffer;
 	public abstract fun peek ()Laws/smithy/kotlin/runtime/io/SdkBufferedSource;
 	public abstract fun read ([BII)I
+	public static synthetic fun read$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSource;[BIIILjava/lang/Object;)I
 	public abstract fun readAll (Laws/smithy/kotlin/runtime/io/SdkSink;)J
 	public abstract fun readByte ()B
 	public abstract fun readByteArray ()[B
@@ -964,7 +974,7 @@ public final class aws/smithy/kotlin/runtime/io/SdkBufferedSource$DefaultImpls {
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/io/SdkByteChannel : aws/smithy/kotlin/runtime/io/SdkByteReadChannel, aws/smithy/kotlin/runtime/io/SdkByteWriteChannel {
-	public abstract fun close ()V
+	public fun close ()V
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkByteChannel$DefaultImpls {
@@ -1011,6 +1021,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkByteWriteChannel
 	public abstract fun getTotalBytesWritten ()J
 	public abstract fun isClosedForWrite ()Z
 	public abstract fun write (Laws/smithy/kotlin/runtime/io/SdkBuffer;JLkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun write$default (Laws/smithy/kotlin/runtime/io/SdkByteWriteChannel;Laws/smithy/kotlin/runtime/io/SdkBuffer;JLkotlin/coroutines/Continuation;ILjava/lang/Object;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkByteWriteChannel$DefaultImpls {
@@ -1231,6 +1242,7 @@ public final class aws/smithy/kotlin/runtime/net/HostKt {
 public abstract interface class aws/smithy/kotlin/runtime/net/HostResolver {
 	public static final field Companion Laws/smithy/kotlin/runtime/net/HostResolver$Companion;
 	public abstract fun purgeCache (Laws/smithy/kotlin/runtime/net/HostAddress;)V
+	public static synthetic fun purgeCache$default (Laws/smithy/kotlin/runtime/net/HostResolver;Laws/smithy/kotlin/runtime/net/HostAddress;ILjava/lang/Object;)V
 	public abstract fun reportFailure (Laws/smithy/kotlin/runtime/net/HostAddress;)V
 	public abstract fun resolve (Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
@@ -2108,7 +2120,6 @@ public final class aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctionsJVMKt
 
 public final class aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctionsKt {
 	public static final fun getDefaultPrinter ()Ljava/lang/Appendable;
-	public static final fun printExceptionStackTrace (Ljava/lang/Exception;)V
 }
 
 public final class aws/smithy/kotlin/runtime/text/Scanner {
@@ -2164,8 +2175,8 @@ public final class aws/smithy/kotlin/runtime/text/encoding/Encodable$Companion {
 public abstract interface class aws/smithy/kotlin/runtime/text/encoding/Encoding {
 	public static final field Companion Laws/smithy/kotlin/runtime/text/encoding/Encoding$Companion;
 	public abstract fun decode (Ljava/lang/String;)Ljava/lang/String;
-	public abstract fun encodableFromDecoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
-	public abstract fun encodableFromEncoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
+	public fun encodableFromDecoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
+	public fun encodableFromEncoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
 	public abstract fun encode (Ljava/lang/String;)Ljava/lang/String;
 	public abstract fun getName ()Ljava/lang/String;
 }
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt
new file mode 100644
index 0000000000..b4588d9280
--- /dev/null
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt
@@ -0,0 +1,42 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.collections
+
+import aws.smithy.kotlin.runtime.util.ExpiringValue
+
+/**
+ * A multi-value cache which supports retrieval and invalidation via a key paired with each value. The [get] and
+ * [invalidate] methods are `suspend` functions to allow for cross-context synchronization and potentially-expensive
+ * value lookup.
+ *
+ * Values in the cache _may_ expire and are retrieved as [ExpiringValue]. When a value is absent/expired in the cache,
+ * invoking [get] will cause a lookup to occur via the function's `valueLookup` parameter.
+ *
+ * @param K The type of the keys of this cache
+ * @param V The type of the values of this cache
+ */
+public interface ExpiringKeyedCache<K, V> {
+    /**
+     * The number of values currently stored in the cache
+     */
+    public val size: Int
+
+    /**
+     * Gets the value associated with this key from the cache. If the cache does not contain the given key,
+     * implementations are expected to invoke [valueLookup], although they _may_ perform other actions such as throw
+     * exceptions, fall back to other caches, etc.
+     * @param key The key for which to look up a value
+     * @param valueLookup A possibly-suspending function which returns the read-through value associated with a given
+     * key. This function is invoked when the cache does not contain the given [key] or when the value is expired.
+     */
+    public suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V
+
+    /**
+     * Invalidates the value (if any) for the given key, removing it from the cache regardless. This method has no
+     * effect if the given key is not present in the cache.
+     * @param key The key for which to invalidate a value
+     */
+    public suspend fun invalidate(key: K)
+}
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
similarity index 74%
rename from runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt
rename to runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
index 529a57d450..0940aaec2d 100644
--- a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
@@ -12,8 +12,9 @@ import kotlinx.coroutines.sync.withLock
 import kotlin.time.Duration
 
 /**
- * An object which caches values and allows retrieving them by key. The values expire after a time. If a value is
- * expired or absent from the cache, it will be read from a `valueLookup` parameter passed to [get] and then cached.
+ * A cache which allows retrieving values by a key. Looking up a value for a key which does not exist in the cache (or
+ * where the value has expired) are resolved by calling [valueLookup]. The expiry for a value is included in the result
+ * returned from [valueLookup].
  *
  * A sweep operation will run prior to a [get] or [invalidate] that happens after [minimumSweepPeriod] has elapsed from
  * the last sweep (or from the initialization of the cache). This sweep will search for and remove expired entries from
@@ -29,10 +30,10 @@ import kotlin.time.Duration
  * @param clock The [Clock] to use for measuring time. Defaults to [Clock.System].
  */
 @InternalApi
-public class ReadThroughCache<K, V>(
+public class PeriodicSweepCache<K, V>(
     private val minimumSweepPeriod: Duration,
     private val clock: Clock = Clock.System,
-) {
+) : ExpiringKeyedCache<K, V> {
     private val map = mutableMapOf<K, ExpiringValue<V>>()
     private val mutex = Mutex()
     private var nextSweep = clock.now() + minimumSweepPeriod
@@ -44,7 +45,7 @@ public class ReadThroughCache<K, V>(
      * @param valueLookup A possibly-suspending function which returns the read-through value associated with a given
      * key. This function is invoked when the cache, for a given key, does not contain a value or the value is expired.
      */
-    public suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V = mutex.withLock {
+    override suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V = mutex.withLock {
         if (clock.now() > nextSweep) sweep()
 
         val current = map[key]
@@ -59,20 +60,29 @@ public class ReadThroughCache<K, V>(
      * Invalidates the value (if any) for the given key, removing it from the cache regardless of its expiry.
      * @param key The key for which to invalidate a value.
      */
-    public suspend fun invalidate(key: K): Unit = mutex.withLock {
+    override suspend fun invalidate(key: K): Unit = mutex.withLock {
         map.remove(key)
         if (clock.now() > nextSweep) sweep()
     }
 
+    /**
+     * Indicates whether this value is expired according to its [ExpiringValue.expiresAt] property and the cache's
+     * [clock]
+     */
     private val ExpiringValue<*>.isExpired: Boolean
         get() = clock.now() >= expiresAt
 
     /**
-     * Gets the number of values currently stored in the cache.
+     * Gets the number of values currently stored in the cache. Note that this property is non-volatile and may reflect
+     * stale information in highly-concurrent scenarios.
      */
-    public val size: Int
+    override val size: Int
         get() = map.size
 
+    /**
+     * Sweeps the cache to remove expired entries and schedule the next sweep. This method _must_ be invoked under mutex
+     * lock.
+     */
     private fun sweep() {
         val iterator = map.iterator()
         while (iterator.hasNext()) {
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
index 3da3bb8c23..9cab81bdbc 100644
--- a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
@@ -2,27 +2,6 @@ package aws.smithy.kotlin.runtime.smoketests
 
 public expect fun exitProcess(status: Int): Nothing
 
-/**
- * Prints an exceptions stack trace using test anything protocol (TAP) format e.g.
- *
- * #java.lang.ArithmeticException: / by zero
- * #	at FileKt.main(File.kt:3)
- * #	at FileKt.main(File.kt)
- * #	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
- * #	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
- * #	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
- * #	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
- * #	at executors.JavaRunnerExecutor$Companion.main(JavaRunnerExecutor.kt:27)
- * #	at executors.JavaRunnerExecutor.main(JavaRunnerExecutor.kt)
- */
-@Deprecated(
-    message = "No longer used, target for removal in 1.5",
-    replaceWith = ReplaceWith("println(exception.stackTraceToString().prependIndent(\"#\"))"),
-    level = DeprecationLevel.WARNING,
-)
-public fun printExceptionStackTrace(exception: Exception): Unit =
-    println(exception.stackTraceToString().split("\n").joinToString("\n") { "#$it" })
-
 public class SmokeTestsException(message: String) : Exception(message)
 
 /**
diff --git a/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt b/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
similarity index 91%
rename from runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt
rename to runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
index 4d85ece15f..f070669c1f 100644
--- a/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt
+++ b/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
@@ -12,13 +12,13 @@ import kotlin.test.assertEquals
 import kotlin.time.Duration.Companion.minutes
 import kotlin.time.Duration.Companion.seconds
 
-class ReadThroughCacheTest {
+class PeriodicSweepCacheTest {
     @Test
-    fun testReadThrough() = runTest {
+    fun testGet() = runTest {
         val clock = ManualClock()
         var counter = 0
         fun uncachedValue() = ExpiringValue(counter++, clock.now() + 2.seconds)
-        val cache = ReadThroughCache<String, Int>(1.minutes, clock)
+        val cache = PeriodicSweepCache<String, Int>(1.minutes, clock)
 
         // Basic read through
         assertEquals(0, cache.get("a") { uncachedValue() })
@@ -41,7 +41,7 @@ class ReadThroughCacheTest {
         val clock = ManualClock()
         var counter = 0
         fun uncachedValue() = ExpiringValue(counter++, clock.now() + 2.seconds)
-        val cache = ReadThroughCache<String, Int>(4.seconds, clock)
+        val cache = PeriodicSweepCache<String, Int>(4.seconds, clock)
 
         // Pre-populate values
         assertEquals(0, cache.get("a") { uncachedValue() })
diff --git a/runtime/serde/serde-xml/api/serde-xml.api b/runtime/serde/serde-xml/api/serde-xml.api
index 736408bd97..eabc8febb8 100644
--- a/runtime/serde/serde-xml/api/serde-xml.api
+++ b/runtime/serde/serde-xml/api/serde-xml.api
@@ -47,16 +47,6 @@ public final class aws/smithy/kotlin/runtime/serde/xml/XmlCollectionValueNamespa
 	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 }
 
-public final class aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer : aws/smithy/kotlin/runtime/serde/Deserializer {
-	public fun <init> (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;Z)V
-	public synthetic fun <init> (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;ZILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public fun <init> ([BZ)V
-	public synthetic fun <init> ([BZILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public fun deserializeList (Laws/smithy/kotlin/runtime/serde/SdkFieldDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$ElementIterator;
-	public fun deserializeMap (Laws/smithy/kotlin/runtime/serde/SdkFieldDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$EntryIterator;
-	public fun deserializeStruct (Laws/smithy/kotlin/runtime/serde/SdkObjectDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$FieldIterator;
-}
-
 public final class aws/smithy/kotlin/runtime/serde/xml/XmlError : aws/smithy/kotlin/runtime/serde/FieldTrait {
 	public static final field INSTANCE Laws/smithy/kotlin/runtime/serde/xml/XmlError;
 	public final fun getErrorTag ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken$QualifiedName;
@@ -155,8 +145,10 @@ public abstract interface class aws/smithy/kotlin/runtime/serde/xml/XmlStreamRea
 	public abstract fun getLastToken ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun nextToken ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun peek (I)Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
+	public static synthetic fun peek$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;IILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun skipNext ()V
 	public abstract fun subTreeReader (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$SubtreeStartDepth;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;
+	public static synthetic fun subTreeReader$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$SubtreeStartDepth;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;
 }
 
 public final class aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$DefaultImpls {
@@ -178,13 +170,17 @@ public final class aws/smithy/kotlin/runtime/serde/xml/XmlStreamReaderKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter {
 	public abstract fun attribute (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun attribute$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun endDocument ()V
 	public abstract fun endTag (Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun endTag$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun getBytes ()[B
 	public abstract fun getText ()Ljava/lang/String;
 	public abstract fun namespacePrefix (Ljava/lang/String;Ljava/lang/String;)V
+	public static synthetic fun namespacePrefix$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)V
 	public abstract fun startDocument ()V
 	public abstract fun startTag (Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun startTag$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun text (Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 }
 
diff --git a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt
deleted file mode 100644
index b950e888b6..0000000000
--- a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt
+++ /dev/null
@@ -1,431 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package aws.smithy.kotlin.runtime.serde.xml
-
-import aws.smithy.kotlin.runtime.InternalApi
-import aws.smithy.kotlin.runtime.content.BigDecimal
-import aws.smithy.kotlin.runtime.content.BigInteger
-import aws.smithy.kotlin.runtime.content.Document
-import aws.smithy.kotlin.runtime.serde.*
-import aws.smithy.kotlin.runtime.text.encoding.decodeBase64Bytes
-import aws.smithy.kotlin.runtime.time.Instant
-import aws.smithy.kotlin.runtime.time.TimestampFormat
-
-private const val FIRST_FIELD_INDEX: Int = 0
-
-// Represents aspects of SdkFieldDescriptor that are particular to the Xml format
-internal sealed class FieldLocation {
-    // specifies the mapping to a sdk field index
-    abstract val fieldIndex: Int
-
-    data class Text(override val fieldIndex: Int) : FieldLocation() // Xml nodes have only one associated Text element
-    data class Attribute(override val fieldIndex: Int, val names: Set<XmlToken.QualifiedName>) : FieldLocation()
-}
-
-/**
- * Provides a deserializer for XML documents
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param validateRootElement Flag indicating if the root XML document [XmlToken.BeginElement] should be validated against
- * the descriptor passed to [deserializeStruct]. This only affects the root element, not nested struct elements. Some
- * restXml based services DO NOT always send documents with a root element name that matches the shape ID name
- * (S3 in particular). This means there is nothing in the model that gives you enough information to validate the tag.
- */
-@Deprecated("XmlDeserializer is deprecated and will be removed in a future release")
-@InternalApi
-public class XmlDeserializer(
-    private val reader: XmlStreamReader,
-    private val validateRootElement: Boolean = false,
-) : Deserializer {
-
-    public constructor(input: ByteArray, validateRootElement: Boolean = false) : this(xmlStreamReader(input), validateRootElement)
-
-    private var firstStructCall = true
-
-    override fun deserializeStruct(descriptor: SdkObjectDescriptor): Deserializer.FieldIterator {
-        if (firstStructCall) {
-            if (!descriptor.hasTrait<XmlSerialName>()) throw DeserializationException("Top-level struct $descriptor requires a XmlSerialName trait but has none.")
-
-            firstStructCall = false
-
-            reader.nextToken() // Matching field descriptors to children tags so consume the start element of top-level struct
-
-            val structToken = if (descriptor.hasTrait<XmlError>()) {
-                reader.seek<XmlToken.BeginElement> { it.name == descriptor.expectTrait<XmlError>().errorTag }
-            } else {
-                reader.seek<XmlToken.BeginElement>()
-            } ?: throw DeserializationException("Could not find a begin element for new struct")
-
-            if (validateRootElement) {
-                descriptor.requireNameMatch(structToken.name.tag)
-            }
-        }
-
-        // Consume any remaining terminating tokens from previous deserialization
-        reader.seek<XmlToken.BeginElement>()
-
-        // Because attributes set on the root node of the struct, we must read the values before creating the subtree
-        val attribFields = reader.tokenAttributesToFieldLocations(descriptor)
-        val parentToken = if (reader.lastToken is XmlToken.BeginElement) {
-            reader.lastToken as XmlToken.BeginElement
-        } else {
-            throw DeserializationException("Expected last parsed token to be ${XmlToken.BeginElement::class} but was ${reader.lastToken}")
-        }
-
-        val unwrapped = descriptor.hasTrait<XmlUnwrappedOutput>()
-        return XmlStructDeserializer(descriptor, reader.subTreeReader(XmlStreamReader.SubtreeStartDepth.CURRENT), parentToken, attribFields, unwrapped)
-    }
-
-    override fun deserializeList(descriptor: SdkFieldDescriptor): Deserializer.ElementIterator {
-        val depth = when (descriptor.hasTrait<Flattened>()) {
-            true -> XmlStreamReader.SubtreeStartDepth.CURRENT
-            else -> XmlStreamReader.SubtreeStartDepth.CHILD
-        }
-
-        return XmlListDeserializer(reader.subTreeReader(depth), descriptor)
-    }
-
-    override fun deserializeMap(descriptor: SdkFieldDescriptor): Deserializer.EntryIterator {
-        val depth = when (descriptor.hasTrait<Flattened>()) {
-            true -> XmlStreamReader.SubtreeStartDepth.CURRENT
-            else -> XmlStreamReader.SubtreeStartDepth.CHILD
-        }
-
-        return XmlMapDeserializer(reader.subTreeReader(depth), descriptor)
-    }
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce Maps
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param descriptor associated [SdkFieldDescriptor] which represents the expected Map
- * @param primitiveDeserializer used to deserialize primitive values
- */
-internal class XmlMapDeserializer(
-    private val reader: XmlStreamReader,
-    private val descriptor: SdkFieldDescriptor,
-    private val primitiveDeserializer: PrimitiveDeserializer = XmlPrimitiveDeserializer(reader, descriptor),
-) : PrimitiveDeserializer by primitiveDeserializer,
-    Deserializer.EntryIterator {
-    private val mapTrait = descriptor.findTrait<XmlMapName>() ?: XmlMapName.Default
-
-    override fun hasNextEntry(): Boolean {
-        val compareTo = when (descriptor.hasTrait<Flattened>()) {
-            true -> descriptor.findTrait<XmlSerialName>()?.name ?: mapTrait.key // Prefer seeking to XmlSerialName if the trait exists
-            false -> mapTrait.entry
-        }
-
-        // Seek to either the XML serial name, entry, or key token depending on the flatness of the map and if the name trait is present
-        val nextEntryToken = when (descriptor.hasTrait<Flattened>()) {
-            true -> reader.peekSeek<XmlToken.BeginElement> { it.name.local == compareTo }
-            false -> reader.seek<XmlToken.BeginElement> { it.name.local == compareTo }
-        }
-
-        return nextEntryToken != null
-    }
-
-    override fun key(): String {
-        // Seek to the key begin token
-        reader.seek<XmlToken.BeginElement> { it.name.local == mapTrait.key }
-            ?: error("Unable to find key $mapTrait.key in $descriptor")
-
-        val keyValueToken = reader.takeNextAs<XmlToken.Text>()
-        reader.nextToken() // Consume the end wrapper
-
-        return keyValueToken.value ?: throw DeserializationException("Key unspecified in $descriptor")
-    }
-
-    override fun nextHasValue(): Boolean {
-        // Expect a begin and value (or another begin) token if Map entry has a value
-        val peekBeginToken = reader.peek(1) ?: throw DeserializationException("Unexpected termination of token stream in $descriptor")
-        val peekValueToken = reader.peek(2) ?: throw DeserializationException("Unexpected termination of token stream in $descriptor")
-
-        return peekBeginToken !is XmlToken.EndElement && peekValueToken !is XmlToken.EndElement
-    }
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce Lists
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param descriptor associated [SdkFieldDescriptor] which represents the expected Map
- * @param primitiveDeserializer used to deserialize primitive values
- */
-internal class XmlListDeserializer(
-    private val reader: XmlStreamReader,
-    private val descriptor: SdkFieldDescriptor,
-    private val primitiveDeserializer: PrimitiveDeserializer = XmlPrimitiveDeserializer(reader, descriptor),
-) : PrimitiveDeserializer by primitiveDeserializer,
-    Deserializer.ElementIterator {
-    private var firstCall = true
-    private val flattened = descriptor.hasTrait<Flattened>()
-    private val elementName = (descriptor.findTrait<XmlCollectionName>() ?: XmlCollectionName.Default).element
-
-    override fun hasNextElement(): Boolean {
-        if (!flattened && firstCall) {
-            val nextToken = reader.peek()
-            val matchedListDescriptor = nextToken is XmlToken.BeginElement && descriptor.nameMatches(nextToken.name.tag)
-            val hasChildren = if (nextToken == null) false else nextToken.depth >= reader.lastToken!!.depth
-
-            if (!matchedListDescriptor && !hasChildren) return false
-
-            // Discard the wrapper and move to the first element in the list
-            if (matchedListDescriptor) reader.nextToken()
-
-            firstCall = false
-        }
-
-        if (flattened) {
-            // Because our subtree is not CHILD, we cannot rely on the subtree boundary to determine end of collection.
-            // Rather, we search for either the next begin token matching the (flat) list member name which should
-            // be immediately after the current token
-
-            // peek at the next token if there is one, in the case of a list of structs, the next token is actually
-            // the end of the current flat list element in which case we need to peek twice
-            val next = when (val peeked = reader.peek()) {
-                is XmlToken.EndElement -> {
-                    if (peeked.name.local == descriptor.serialName.name) {
-                        // consume the end token
-                        reader.nextToken()
-                        reader.peek()
-                    } else {
-                        peeked
-                    }
-                }
-                else -> peeked
-            }
-
-            val tokens = listOfNotNull(reader.lastToken, next)
-
-            // Iterate over the token stream until begin token matching name is found or end element matching list is found.
-            return tokens
-                .filterIsInstance<XmlToken.BeginElement>()
-                .any { it.name.local == descriptor.serialName.name }
-        } else {
-            // If we can find another begin token w/ the element name, we have more elements to process
-            return reader.seek<XmlToken.BeginElement> { it.name.local == elementName }.isNotTerminal()
-        }
-    }
-
-    override fun nextHasValue(): Boolean = reader.peek() !is XmlToken.EndElement
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce structures
- *
- * @param objDescriptor associated [SdkObjectDescriptor] which represents the expected structure
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param parentToken initial token of associated structure
- * @param parsedFieldLocations list of [FieldLocation] representing values able to be loaded into deserialized instances
- */
-private class XmlStructDeserializer(
-    private val objDescriptor: SdkObjectDescriptor,
-    reader: XmlStreamReader,
-    private val parentToken: XmlToken.BeginElement,
-    private val parsedFieldLocations: MutableList<FieldLocation> = mutableListOf(),
-    private val unwrapped: Boolean,
-) : Deserializer.FieldIterator {
-    // Used to track direct deserialization or further nesting between calls to findNextFieldIndex() and deserialize<Type>()
-    private var reentryFlag: Boolean = false
-
-    private val reader: XmlStreamReader = if (unwrapped) reader else reader.subTreeReader(XmlStreamReader.SubtreeStartDepth.CHILD)
-
-    override fun findNextFieldIndex(): Int? {
-        if (unwrapped) {
-            return if (reader.peek() is XmlToken.Text) FIRST_FIELD_INDEX else null
-        }
-        if (inNestedMode()) {
-            // Returning from a nested struct call.  Nested deserializer consumed
-            // tokens so clear them here to avoid processing stale state
-            parsedFieldLocations.clear()
-        }
-
-        if (parsedFieldLocations.isEmpty()) {
-            val matchedFieldLocations = when (val token = reader.nextToken()) {
-                null, is XmlToken.EndDocument -> return null
-                is XmlToken.EndElement -> return findNextFieldIndex()
-                is XmlToken.BeginElement -> {
-                    val nextToken = reader.peek() ?: return null
-                    val objectFields = objDescriptor.fields
-                    val memberFields = objectFields.filter { field -> objDescriptor.fieldTokenMatcher(field, token) }
-                    val matchingFields = memberFields.mapNotNull { it.findFieldLocation(token, nextToken) }
-                    matchingFields
-                }
-                else -> return findNextFieldIndex()
-            }
-
-            // Sorting ensures attribs are processed before text, as processing the Text token pushes the parser on to the next token.
-            parsedFieldLocations.addAll(matchedFieldLocations.sortedBy { it is FieldLocation.Text })
-        }
-
-        return parsedFieldLocations.firstOrNull()?.fieldIndex ?: Deserializer.FieldIterator.UNKNOWN_FIELD
-    }
-
-    private fun <T> deserializeValue(transform: ((String) -> T)): T {
-        if (unwrapped) {
-            val value = reader.takeNextAs<XmlToken.Text>().value ?: ""
-            return transform(value)
-        }
-        // Set and validate mode
-        reentryFlag = false
-        if (parsedFieldLocations.isEmpty()) throw DeserializationException("matchedFields is empty, was findNextFieldIndex() called?")
-
-        // Take the first FieldLocation and attempt to parse it into the value specified by the descriptor.
-        return when (val nextField = parsedFieldLocations.removeFirst()) {
-            is FieldLocation.Text -> {
-                val value = when (val peekToken = reader.peek()) {
-                    is XmlToken.Text -> reader.takeNextAs<XmlToken.Text>().value ?: ""
-                    is XmlToken.EndElement -> ""
-                    else -> throw DeserializationException("Unexpected token $peekToken")
-                }
-                transform(value)
-            }
-            is FieldLocation.Attribute -> {
-                transform(
-                    nextField
-                        .names
-                        .mapNotNull { parentToken.attributes[it] }
-                        .firstOrNull() ?: throw DeserializationException("Expected attrib value ${nextField.names.first()} not found in ${parentToken.name}"),
-                )
-            }
-        }
-    }
-
-    override fun skipValue() = reader.skipNext()
-
-    override fun deserializeByte(): Byte = deserializeValue { it.toIntOrNull()?.toByte() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeInt(): Int = deserializeValue { it.toIntOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeShort(): Short = deserializeValue { it.toIntOrNull()?.toShort() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeLong(): Long = deserializeValue { it.toLongOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeFloat(): Float = deserializeValue { it.toFloatOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeDouble(): Double = deserializeValue { it.toDoubleOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeBigInteger(): BigInteger = deserializeValue {
-        runCatching { BigInteger(it) }
-            .getOrElse { throw DeserializationException("Unable to deserialize $it as BigInteger") }
-    }
-
-    override fun deserializeBigDecimal(): BigDecimal = deserializeValue {
-        runCatching { BigDecimal(it) }
-            .getOrElse { throw DeserializationException("Unable to deserialize $it as BigDecimal") }
-    }
-
-    override fun deserializeString(): String = deserializeValue { it }
-
-    override fun deserializeBoolean(): Boolean = deserializeValue { it.toBoolean() }
-
-    override fun deserializeDocument(): Document = throw DeserializationException("cannot deserialize unsupported Document type in xml")
-
-    override fun deserializeByteArray(): ByteArray = deserializeString().decodeBase64Bytes()
-
-    override fun deserializeInstant(format: TimestampFormat): Instant = when (format) {
-        TimestampFormat.EPOCH_SECONDS -> deserializeString().let { Instant.fromEpochSeconds(it) }
-        TimestampFormat.ISO_8601 -> deserializeString().let { Instant.fromIso8601(it) }
-        TimestampFormat.RFC_5322 -> deserializeString().let { Instant.fromRfc5322(it) }
-        else -> throw DeserializationException("unknown timestamp format: $format")
-    }
-
-    override fun deserializeNull(): Nothing? {
-        reader.takeNextAs<XmlToken.EndElement>()
-        return null
-    }
-
-    // A struct deserializer can be called in two "modes":
-    // 1. to deserialize a value.  This calls findNextFieldIndex() followed by deserialize<SomePrimitiveType>()
-    // 2. to deserialize a nested container. This calls findNextFieldIndex() followed by a call to another deserialize<Struct/List/Map>()
-    // Because state is built in findNextFieldIndex() that is intended to be used directly in deserialize<SomePrimitiveType>() (mode 1)
-    // and there is no explicit way that this type knows which mode is in use, the state built must be cleared.
-    // this is done by flipping a bit between the two calls.  If the bit has not been flipped on any call to findNextFieldIndex()
-    // it is determined that the nested mode was used and any existing state should be cleared.
-    // if the state is not cleared, deserialization goes into an infinite loop because the deserializer sees pending fields to pull from the stream
-    // which are never consumed by the (missing) call to deserialize<SomePrimitiveType>()
-    private fun inNestedMode(): Boolean = when (reentryFlag) {
-        true -> true
-        false -> {
-            reentryFlag = true
-            false
-        }
-    }
-}
-
-// Extract the attributes from the last-read token and match them to [FieldLocation] on the [SdkObjectDescriptor].
-private fun XmlStreamReader.tokenAttributesToFieldLocations(descriptor: SdkObjectDescriptor): MutableList<FieldLocation> =
-    if (descriptor.hasXmlAttributes && lastToken is XmlToken.BeginElement) {
-        val attribFields = descriptor.fields.filter { it.hasTrait<XmlAttribute>() }
-        val matchedAttribFields = attribFields.filter { it.findFieldLocation(lastToken as XmlToken.BeginElement, peek() ?: throw DeserializationException("Unexpected end of tokens")) != null }
-        matchedAttribFields.map { FieldLocation.Attribute(it.index, it.toQualifiedNames()) }
-            .toMutableList()
-    } else {
-        mutableListOf()
-    }
-
-// Returns a [FieldLocation] if the field maps to the current token
-private fun SdkFieldDescriptor.findFieldLocation(
-    currentToken: XmlToken.BeginElement,
-    nextToken: XmlToken,
-): FieldLocation? = when (val property = toFieldLocation()) {
-    is FieldLocation.Text -> {
-        when {
-            nextToken is XmlToken.Text -> property
-            nextToken is XmlToken.BeginElement -> property
-            // The following allows for struct primitives to remain unvisited if no value
-            // but causes nested deserializers to be called even if they contain no value
-            nextToken is XmlToken.EndElement && currentToken.name == nextToken.name -> property
-            else -> null
-        }
-    }
-    is FieldLocation.Attribute -> {
-        val foundMatch = property.names.any { currentToken.attributes[it]?.isNotBlank() == true }
-        if (foundMatch) property else null
-    }
-}
-
-// Produce a [FieldLocation] type based on presence of traits of field
-// A field without an attribute trait is assumed to be a text token
-private fun SdkFieldDescriptor.toFieldLocation(): FieldLocation =
-    when (findTrait<XmlAttribute>()) {
-        null -> FieldLocation.Text(index) // Assume a text value if no attributes defined.
-        else -> FieldLocation.Attribute(index, toQualifiedNames())
-    }
-
-// Matches fields and tokens with matching qualified name
-private fun SdkObjectDescriptor.fieldTokenMatcher(fieldDescriptor: SdkFieldDescriptor, beginElement: XmlToken.BeginElement): Boolean {
-    if (fieldDescriptor.kind == SerialKind.List && fieldDescriptor.hasTrait<Flattened>()) {
-        val fieldName = fieldDescriptor.findTrait<XmlCollectionName>() ?: XmlCollectionName.Default
-        val tokenQname = beginElement.name
-
-        // It may be that we are matching a flattened list element or matching a list itself.  In the latter
-        // case the following predicate will not work, so if we fail to match the member
-        // try again (below) to match against the container.
-        if (fieldName.element == tokenQname.local) return true
-    }
-
-    return fieldDescriptor.nameMatches(beginElement.name.tag)
-}
-
-/**
- * Return the next token of the specified type or throw [DeserializationException] if incorrect type.
- */
-internal inline fun <reified TExpected : XmlToken> XmlStreamReader.takeNextAs(): TExpected {
-    val token = this.nextToken() ?: throw DeserializationException("Expected ${TExpected::class} but instead found null")
-    requireToken<TExpected>(token)
-    return token as TExpected
-}
-
-/**
- * Require that the given token be of type [TExpected] or else throw an exception
- */
-internal inline fun <reified TExpected> requireToken(token: XmlToken) {
-    if (token::class != TExpected::class) {
-        throw DeserializationException("Expected ${TExpected::class}; found ${token::class} ($token)")
-    }
-}
diff --git a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
index a43250b267..760f52a833 100644
--- a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
+++ b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
@@ -6,6 +6,7 @@
 package aws.smithy.kotlin.runtime.serde.xml
 
 import aws.smithy.kotlin.runtime.InternalApi
+import aws.smithy.kotlin.runtime.serde.DeserializationException
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.LexingXmlStreamReader
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.StringTextStream
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.XmlLexer
@@ -114,6 +115,24 @@ public inline fun <reified T : XmlToken> XmlStreamReader.peekSeek(selectionPredi
     return null
 }
 
+/**
+ * Return the next token of the specified type or throw [DeserializationException] if incorrect type.
+ */
+internal inline fun <reified TExpected : XmlToken> XmlStreamReader.takeNextAs(): TExpected {
+    val token = this.nextToken() ?: throw DeserializationException("Expected ${TExpected::class} but instead found null")
+    requireToken<TExpected>(token)
+    return token as TExpected
+}
+
+/**
+ * Require that the given token be of type [TExpected] or else throw an exception
+ */
+private inline fun <reified TExpected> requireToken(token: XmlToken) {
+    if (token::class != TExpected::class) {
+        throw DeserializationException("Expected ${TExpected::class}; found ${token::class} ($token)")
+    }
+}
+
 /**
  * Creates an [XmlStreamReader] instance
  */
diff --git a/runtime/smithy-client/api/smithy-client.api b/runtime/smithy-client/api/smithy-client.api
index b6132b26b8..823ff0467d 100644
--- a/runtime/smithy-client/api/smithy-client.api
+++ b/runtime/smithy-client/api/smithy-client.api
@@ -30,47 +30,25 @@ public final class aws/smithy/kotlin/runtime/client/IdempotencyTokenProvider$Com
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/client/Interceptor {
-	public abstract fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterExecution (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readAfterSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public abstract fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public abstract fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public abstract fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public abstract fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-}
-
-public final class aws/smithy/kotlin/runtime/client/Interceptor$DefaultImpls {
-	public static fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterExecution (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readAfterSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public static fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public static fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public static fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public static fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterExecution (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readAfterSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
+	public fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
+	public fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
+	public fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
+	public fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
 }
 
 public abstract class aws/smithy/kotlin/runtime/client/LogMode {
@@ -187,7 +165,7 @@ public abstract interface class aws/smithy/kotlin/runtime/client/SdkClientConfig
 
 public abstract interface class aws/smithy/kotlin/runtime/client/SdkClientFactory {
 	public abstract fun builder ()Laws/smithy/kotlin/runtime/client/SdkClient$Builder;
-	public abstract fun invoke (Lkotlin/jvm/functions/Function1;)Laws/smithy/kotlin/runtime/client/SdkClient;
+	public fun invoke (Lkotlin/jvm/functions/Function1;)Laws/smithy/kotlin/runtime/client/SdkClient;
 }
 
 public final class aws/smithy/kotlin/runtime/client/SdkClientFactory$DefaultImpls {
@@ -225,7 +203,7 @@ public abstract interface class aws/smithy/kotlin/runtime/client/config/Compress
 
 public abstract interface class aws/smithy/kotlin/runtime/client/config/CompressionClientConfig$Builder {
 	public abstract fun getRequestCompression ()Laws/smithy/kotlin/runtime/client/config/RequestCompressionConfig$Builder;
-	public abstract fun requestCompression (Lkotlin/jvm/functions/Function1;)V
+	public fun requestCompression (Lkotlin/jvm/functions/Function1;)V
 }
 
 public final class aws/smithy/kotlin/runtime/client/config/CompressionClientConfig$Builder$DefaultImpls {
@@ -353,3 +331,15 @@ public final class aws/smithy/kotlin/runtime/client/endpoints/functions/Url {
 	public fun toString ()Ljava/lang/String;
 }
 
+public abstract interface class aws/smithy/kotlin/runtime/client/region/RegionProvider {
+	public abstract fun getRegion (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public class aws/smithy/kotlin/runtime/client/region/RegionProviderChain : aws/smithy/kotlin/runtime/client/region/RegionProvider {
+	public fun <init> (Ljava/util/List;)V
+	public fun <init> ([Laws/smithy/kotlin/runtime/client/region/RegionProvider;)V
+	protected final fun getProviders ()[Laws/smithy/kotlin/runtime/client/region/RegionProvider;
+	public fun getRegion (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun toString ()Ljava/lang/String;
+}
+
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
index 8d2b5c68bc..4fab16b9a7 100644
--- a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
@@ -5,6 +5,7 @@
 
 package aws.smithy.kotlin.runtime.client
 
+import aws.smithy.kotlin.runtime.client.util.MpJvmDefaultWithoutCompatibility
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 
 /**
@@ -20,6 +21,7 @@ import aws.smithy.kotlin.runtime.operation.ExecutionContext
  * **MUST** not modify state even if it is possible to do so (it is not always possible or performant to provide an
  * immutable view of every type).
  */
+@MpJvmDefaultWithoutCompatibility
 public interface Interceptor<
     Input,
     Output,
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt
new file mode 100644
index 0000000000..9e82ec4509
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt
@@ -0,0 +1,17 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+/**
+ * Interface for providing AWS region information. Implementations are free to use any strategy for
+ * providing region information
+ */
+public interface RegionProvider {
+    /**
+     * Return the region name to use. If region information is not available, implementations should return null
+     */
+    public suspend fun getRegion(): String?
+}
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt
new file mode 100644
index 0000000000..0df388d11f
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+import aws.smithy.kotlin.runtime.telemetry.logging.logger
+import aws.smithy.kotlin.runtime.util.asyncLazy
+import kotlin.coroutines.coroutineContext
+
+/**
+ * Composite [RegionProvider] that delegates to a chain of providers.
+ * [providers] are consulted in the order given and the first region found is returned
+ *
+ * @param providers the list of providers to delegate to
+ */
+public open class RegionProviderChain(
+    protected vararg val providers: RegionProvider,
+) : RegionProvider {
+
+    public constructor(providers: List<RegionProvider>) : this(*providers.toTypedArray())
+
+    private val resolvedRegion = asyncLazy(::resolveRegion)
+
+    init {
+        require(providers.isNotEmpty()) { "at least one provider must be in the chain" }
+    }
+
+    override fun toString(): String =
+        (listOf(this) + providers).map { it::class.simpleName }.joinToString(" -> ")
+
+    override suspend fun getRegion(): String? = resolvedRegion.get()
+
+    private suspend fun resolveRegion(): String? {
+        val logger = coroutineContext.logger<RegionProviderChain>()
+        for (provider in providers) {
+            try {
+                val region = provider.getRegion()
+                if (region != null) {
+                    logger.debug { "resolved region ($region) from $provider " }
+                    return region
+                }
+                logger.debug { "failed to resolve region from $provider" }
+            } catch (ex: Exception) {
+                logger.debug { "unable to load region from $provider: ${ex.message}" }
+            }
+        }
+
+        return null
+    }
+}
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt
new file mode 100644
index 0000000000..f7b9449ebc
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt
@@ -0,0 +1,13 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+/**
+ * A KMP-compatible variant of [kotlin.jvm.JvmDefaultWithoutCompatibility]
+ */
+@Retention(AnnotationRetention.SOURCE)
+@Target(AnnotationTarget.CLASS)
+public expect annotation class MpJvmDefaultWithoutCompatibility()
diff --git a/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt b/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt
new file mode 100644
index 0000000000..361336ac2d
--- /dev/null
+++ b/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt
@@ -0,0 +1,47 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+
+class RegionProviderChainTest {
+    @Test
+    fun testNoProviders() {
+        assertFails("at least one provider") {
+            RegionProviderChain()
+        }
+    }
+    data class TestProvider(val region: String? = null) : RegionProvider {
+        override suspend fun getRegion(): String? = region
+    }
+
+    @Test
+    fun testChain() = runTest {
+        val chain = RegionProviderChain(
+            TestProvider(null),
+            TestProvider("us-east-1"),
+            TestProvider("us-east-2"),
+        )
+
+        assertEquals("us-east-1", chain.getRegion())
+    }
+
+    @Test
+    fun testChainList() = runTest {
+        val providers = listOf<RegionProvider>(
+            TestProvider(null),
+            TestProvider("us-east-1"),
+            TestProvider("us-east-2"),
+        )
+
+        val chain = RegionProviderChain(providers)
+
+        assertEquals("us-east-1", chain.getRegion())
+    }
+}
diff --git a/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt b/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt
new file mode 100644
index 0000000000..db7512a9df
--- /dev/null
+++ b/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt
@@ -0,0 +1,8 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+public actual typealias MpJvmDefaultWithoutCompatibility = kotlin.jvm.JvmDefaultWithoutCompatibility
diff --git a/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt b/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt
new file mode 100644
index 0000000000..118ea69bda
--- /dev/null
+++ b/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt
@@ -0,0 +1,10 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+public actual annotation class MpJvmDefaultWithoutCompatibility {
+    // No-op on non-JVM platforms
+}
diff --git a/tests/codegen/waiter-tests/build.gradle.kts b/tests/codegen/waiter-tests/build.gradle.kts
index 72b244a6c9..992a4d471e 100644
--- a/tests/codegen/waiter-tests/build.gradle.kts
+++ b/tests/codegen/waiter-tests/build.gradle.kts
@@ -38,7 +38,7 @@ kotlin.sourceSets.getByName("main") {
 
 tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
     dependsOn(tasks.generateSmithyProjections)
-    kotlinOptions {
+    compilerOptions {
         // generated code has warnings unfortunately
         allWarningsAsErrors = false
     }