diff --git a/.claude/schema-sync.md b/.claude/schema-sync.md
new file mode 100644
index 0000000..5878d70
--- /dev/null
+++ b/.claude/schema-sync.md
@@ -0,0 +1,104 @@
+# Schema Synchronization
+
+Instructions for updating the model files to match the latest ACP schema from https://github.com/agentclientprotocol/agent-client-protocol
+
+## Process
+
+### 1. Fetch Latest Schema Files
+
+Schema URLs:
+- https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/schema.json
+- https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/meta.json
+- https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/schema.unstable.json
+- https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/meta.unstable.json
+
+### 2. Analyze Schema Changes
+
+Use the Task agent to analyze and compare schemas:
+- Read the JSON schema files (large files, read in sections)
+- Identify all types, requests, responses, and notifications
+- Compare with `acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/`
+- Find missing types, fields, or methods
+- Identify items marked as "unstable" in schema
+
+### 3. Update Model Files
+
+Key files in `acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/`:
+- `Types.kt` - Core types and value classes
+- `Capabilities.kt` - Client and Agent capabilities
+- `Requests.kt` - Request and Response types
+- `SessionUpdate.kt` - Session update types
+- `ToolCall.kt` - Tool call related types
+- `Terminal.kt` - Terminal related types
+- `Methods.kt` - AcpMethod enum with all protocol methods
+
+Rules:
+- Mark unstable API with `@UnstableApi` annotation
+- If a type is marked `@UnstableApi`, don't mark its methods
+- Add `_meta: JsonElement?` field to types extending `AcpWithMeta`
+- Use `@EncodeDefault` for optional fields with defaults in capabilities
+- Use `@JsonClassDiscriminator` for sealed classes
+
+### 4. Update Agent/Client Integration
+
+If request/response signatures changed:
+- `acp/src/commonMain/kotlin/com/agentclientprotocol/agent/Agent.kt`
+- `acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentInfo.kt`
+- `acp/src/commonMain/kotlin/com/agentclientprotocol/client/Client.kt`
+- `acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientInfo.kt`
+
+### 5. Update API Dumps
+
+Run: `./gradlew :acp-model:apiDump :acp:apiDump :acp-ktor:apiDump :acp-ktor-client:apiDump :acp-ktor-server:apiDump`
+
+### 6. Update Schema Version Markers
+
+Clone schema repo to get metadata:
+- Repository: https://github.com/agentclientprotocol/agent-client-protocol
+- Get commit hash, date, and SHA256 checksums of schema files
+
+Update in `acp-model/`:
+- `SCHEMA_VERSION.md` - commit hash, date, checksums, changelog
+- `.schema-checksums` - SHA256 checksums for all 4 schema files
+- `.schema-revision` - commit hash
+
+### 7. Verify Build
+
+Run: `./gradlew build`
+
+## Code Patterns
+
+### New Type
+```kotlin
+@Serializable
+public data class NewType(
+    val requiredField: String,
+    val optionalField: String? = null,
+    override val _meta: JsonElement? = null
+) : AcpWithMeta
+```
+
+### Unstable API
+```kotlin
+/**
+ * **UNSTABLE**
+ *
+ * This capability is not part of the spec yet, and may be removed or changed at any point.
+ */
+@UnstableApi
+@Serializable
+public data class UnstableType(
+    val field: String,
+    override val _meta: JsonElement? = null
+) : AcpWithMeta
+```
+
+### New Method
+```kotlin
+// In Methods.kt
+public object NewMethod : AcpRequestResponseMethod<NewRequest, NewResponse>(
+    "method/name",
+    NewRequest.serializer(),
+    NewResponse.serializer()
+)
+```
diff --git a/acp-model/.schema-checksums b/acp-model/.schema-checksums
new file mode 100644
index 0000000..b55fb0b
--- /dev/null
+++ b/acp-model/.schema-checksums
@@ -0,0 +1,11 @@
+# ACP Schema Checksums
+# This file is used for automated verification
+# Format: SHA256 FILENAME
+
+# Stable schemas
+796e38e275a1587b5a711a4b4508cb69825448b70e79b14bdb4256b24688b89d  schema/schema.json
+f242b95def9a9cbfddd2db1a45d8d3d489ad1b4f564a1322547c90a94c647637  schema/meta.json
+
+# Unstable schemas
+4a886716877f97bc24c4c7f1ae24c9ad06a779107afbdf0718110fc50b5135b7  schema/schema.unstable.json
+8ad80116767e0921970b28766c214d7921268653544d5996a8e2814e1244d4d2  schema/meta.unstable.json
diff --git a/acp-model/.schema-revision b/acp-model/.schema-revision
new file mode 100644
index 0000000..d668dd8
--- /dev/null
+++ b/acp-model/.schema-revision
@@ -0,0 +1 @@
+e23620fe29cb24555db8fb8b58b641b680788e5f
diff --git a/acp-model/SCHEMA_VERSION.md b/acp-model/SCHEMA_VERSION.md
new file mode 100644
index 0000000..e2004f7
--- /dev/null
+++ b/acp-model/SCHEMA_VERSION.md
@@ -0,0 +1,70 @@
+# ACP Schema Version
+
+This file tracks the version of the Agent Client Protocol schema that the model classes are based on.
+
+## Schema Source
+- Repository: https://github.com/agentclientprotocol/agent-client-protocol
+- Branch: main
+- Release: v0.9.1
+
+## Schema Files
+
+### Stable Schema
+- **schema.json**
+  - Commit: `e23620fe29cb24555db8fb8b58b641b680788e5f`
+  - Date: 2025-12-01 17:17:19 +0100
+  - SHA256: `796e38e275a1587b5a711a4b4508cb69825448b70e79b14bdb4256b24688b89d`
+  - URL: https://github.com/agentclientprotocol/agent-client-protocol/blob/main/schema/schema.json
+
+- **meta.json**
+  - Commit: `e23620fe29cb24555db8fb8b58b641b680788e5f`
+  - Date: 2025-12-01 17:17:19 +0100
+  - SHA256: `f242b95def9a9cbfddd2db1a45d8d3d489ad1b4f564a1322547c90a94c647637`
+  - URL: https://github.com/agentclientprotocol/agent-client-protocol/blob/main/schema/meta.json
+
+### Unstable Schema
+- **schema.unstable.json**
+  - Commit: `e23620fe29cb24555db8fb8b58b641b680788e5f`
+  - Date: 2025-12-01 17:17:19 +0100
+  - SHA256: `4a886716877f97bc24c4c7f1ae24c9ad06a779107afbdf0718110fc50b5135b7`
+  - URL: https://github.com/agentclientprotocol/agent-client-protocol/blob/main/schema/schema.unstable.json
+
+- **meta.unstable.json**
+  - Commit: `e23620fe29cb24555db8fb8b58b641b680788e5f`
+  - Date: 2025-12-01 17:17:19 +0100
+  - SHA256: `8ad80116767e0921970b28766c214d7921268653544d5996a8e2814e1244d4d2`
+  - URL: https://github.com/agentclientprotocol/agent-client-protocol/blob/main/schema/meta.unstable.json
+
+**Note:** All types from unstable schema must be marked with `@UnstableApi` annotation.
+
+## Last Updated
+- Date: 2025-12-01
+- Updated by: Manual schema synchronization
+
+## Changes in This Version
+- Added `Implementation` type for client/agent identification
+- Added `SessionCapabilities` type (empty, for future expansion)
+- Added `clientInfo` field to `InitializeRequest`
+- Added `agentInfo` field to `InitializeResponse`
+- Added `sessionCapabilities` field to `AgentCapabilities`
+- Changed `AvailableCommandInput` from data class to sealed class with `Unstructured` variant
+- Added `_meta` field to `ToolCallContent.Terminal`
+- Terminal types are now stable (removed unstable warning)
+
+## Verification
+To verify the schema files match:
+```bash
+# Stable schemas
+curl -s https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/schema.json | sha256sum
+# Expected: 796e38e275a1587b5a711a4b4508cb69825448b70e79b14bdb4256b24688b89d
+
+curl -s https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/meta.json | sha256sum
+# Expected: f242b95def9a9cbfddd2db1a45d8d3d489ad1b4f564a1322547c90a94c647637
+
+# Unstable schemas
+curl -s https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/schema.unstable.json | sha256sum
+# Expected: 4a886716877f97bc24c4c7f1ae24c9ad06a779107afbdf0718110fc50b5135b7
+
+curl -s https://raw.githubusercontent.com/agentclientprotocol/agent-client-protocol/main/schema/meta.unstable.json | sha256sum
+# Expected: 8ad80116767e0921970b28766c214d7921268653544d5996a8e2814e1244d4d2
+```
diff --git a/acp-model/api/acp-model.api b/acp-model/api/acp-model.api
index 7de8868..0861988 100644
--- a/acp-model/api/acp-model.api
+++ b/acp-model/api/acp-model.api
@@ -2,6 +2,9 @@ public final class com/agentclientprotocol/acpmodel/LibVersionKt {
 	public static final field LIB_VERSION Ljava/lang/String;
 }
 
+public abstract interface annotation class com/agentclientprotocol/annotations/UnstableApi : java/lang/annotation/Annotation {
+}
+
 public abstract interface class com/agentclientprotocol/model/AcpCapabilities {
 }
 
@@ -143,18 +146,20 @@ public abstract interface class com/agentclientprotocol/model/AcpWithSessionId {
 public final class com/agentclientprotocol/model/AgentCapabilities : com/agentclientprotocol/model/AcpCapabilities, com/agentclientprotocol/model/AcpWithMeta {
 	public static final field Companion Lcom/agentclientprotocol/model/AgentCapabilities$Companion;
 	public fun <init> ()V
-	public fun <init> (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lkotlinx/serialization/json/JsonElement;)V
-	public synthetic fun <init> (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lcom/agentclientprotocol/model/SessionCapabilities;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lcom/agentclientprotocol/model/SessionCapabilities;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Z
 	public final fun component2 ()Lcom/agentclientprotocol/model/PromptCapabilities;
 	public final fun component3 ()Lcom/agentclientprotocol/model/McpCapabilities;
-	public final fun component4 ()Lkotlinx/serialization/json/JsonElement;
-	public final fun copy (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/AgentCapabilities;
-	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/AgentCapabilities;ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/AgentCapabilities;
+	public final fun component4 ()Lcom/agentclientprotocol/model/SessionCapabilities;
+	public final fun component5 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lcom/agentclientprotocol/model/SessionCapabilities;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/AgentCapabilities;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/AgentCapabilities;ZLcom/agentclientprotocol/model/PromptCapabilities;Lcom/agentclientprotocol/model/McpCapabilities;Lcom/agentclientprotocol/model/SessionCapabilities;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/AgentCapabilities;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getLoadSession ()Z
 	public final fun getMcpCapabilities ()Lcom/agentclientprotocol/model/McpCapabilities;
 	public final fun getPromptCapabilities ()Lcom/agentclientprotocol/model/PromptCapabilities;
+	public final fun getSessionCapabilities ()Lcom/agentclientprotocol/model/SessionCapabilities;
 	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
@@ -367,30 +372,43 @@ public final class com/agentclientprotocol/model/AvailableCommand$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
-public final class com/agentclientprotocol/model/AvailableCommandInput {
+public abstract class com/agentclientprotocol/model/AvailableCommandInput {
 	public static final field Companion Lcom/agentclientprotocol/model/AvailableCommandInput$Companion;
-	public fun <init> (Ljava/lang/String;)V
+	public synthetic fun <init> (ILkotlinx/serialization/internal/SerializationConstructorMarker;)V
+	public static final synthetic fun write$Self (Lcom/agentclientprotocol/model/AvailableCommandInput;Lkotlinx/serialization/encoding/CompositeEncoder;Lkotlinx/serialization/descriptors/SerialDescriptor;)V
+}
+
+public final class com/agentclientprotocol/model/AvailableCommandInput$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
+}
+
+public final class com/agentclientprotocol/model/AvailableCommandInput$Unstructured : com/agentclientprotocol/model/AvailableCommandInput, com/agentclientprotocol/model/AcpWithMeta {
+	public static final field Companion Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured$Companion;
+	public fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ljava/lang/String;
-	public final fun copy (Ljava/lang/String;)Lcom/agentclientprotocol/model/AvailableCommandInput;
-	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/AvailableCommandInput;Ljava/lang/String;ILjava/lang/Object;)Lcom/agentclientprotocol/model/AvailableCommandInput;
+	public final fun component2 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getHint ()Ljava/lang/String;
+	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }
 
-public final synthetic class com/agentclientprotocol/model/AvailableCommandInput$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
-	public static final field INSTANCE Lcom/agentclientprotocol/model/AvailableCommandInput$$serializer;
+public final synthetic class com/agentclientprotocol/model/AvailableCommandInput$Unstructured$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
+	public static final field INSTANCE Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured$$serializer;
 	public final fun childSerializers ()[Lkotlinx/serialization/KSerializer;
-	public final fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lcom/agentclientprotocol/model/AvailableCommandInput;
+	public final fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured;
 	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
 	public final fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
-	public final fun serialize (Lkotlinx/serialization/encoding/Encoder;Lcom/agentclientprotocol/model/AvailableCommandInput;)V
+	public final fun serialize (Lkotlinx/serialization/encoding/Encoder;Lcom/agentclientprotocol/model/AvailableCommandInput$Unstructured;)V
 	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
 	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
 }
 
-public final class com/agentclientprotocol/model/AvailableCommandInput$Companion {
+public final class com/agentclientprotocol/model/AvailableCommandInput$Unstructured$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
@@ -945,17 +963,53 @@ public final class com/agentclientprotocol/model/HttpHeader$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
+public final class com/agentclientprotocol/model/Implementation : com/agentclientprotocol/model/AcpWithMeta {
+	public static final field Companion Lcom/agentclientprotocol/model/Implementation$Companion;
+	public fun <init> (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Ljava/lang/String;
+	public final fun component2 ()Ljava/lang/String;
+	public final fun component3 ()Ljava/lang/String;
+	public final fun component4 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/Implementation;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/Implementation;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/Implementation;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getName ()Ljava/lang/String;
+	public final fun getTitle ()Ljava/lang/String;
+	public final fun getVersion ()Ljava/lang/String;
+	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final synthetic class com/agentclientprotocol/model/Implementation$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
+	public static final field INSTANCE Lcom/agentclientprotocol/model/Implementation$$serializer;
+	public final fun childSerializers ()[Lkotlinx/serialization/KSerializer;
+	public final fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lcom/agentclientprotocol/model/Implementation;
+	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
+	public final fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
+	public final fun serialize (Lkotlinx/serialization/encoding/Encoder;Lcom/agentclientprotocol/model/Implementation;)V
+	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
+	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
+}
+
+public final class com/agentclientprotocol/model/Implementation$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
+}
+
 public final class com/agentclientprotocol/model/InitializeRequest : com/agentclientprotocol/model/AcpRequest {
 	public static final field Companion Lcom/agentclientprotocol/model/InitializeRequest$Companion;
-	public fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;)V
-	public synthetic fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()I
 	public final fun component2 ()Lcom/agentclientprotocol/model/ClientCapabilities;
-	public final fun component3 ()Lkotlinx/serialization/json/JsonElement;
-	public final fun copy (ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/InitializeRequest;
-	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/InitializeRequest;ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/InitializeRequest;
+	public final fun component3 ()Lcom/agentclientprotocol/model/Implementation;
+	public final fun component4 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/InitializeRequest;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/InitializeRequest;ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/InitializeRequest;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getClientCapabilities ()Lcom/agentclientprotocol/model/ClientCapabilities;
+	public final fun getClientInfo ()Lcom/agentclientprotocol/model/Implementation;
 	public final fun getProtocolVersion ()I
 	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 	public fun hashCode ()I
@@ -979,16 +1033,18 @@ public final class com/agentclientprotocol/model/InitializeRequest$Companion {
 
 public final class com/agentclientprotocol/model/InitializeResponse : com/agentclientprotocol/model/AcpResponse {
 	public static final field Companion Lcom/agentclientprotocol/model/InitializeResponse$Companion;
-	public fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;)V
-	public synthetic fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()I
 	public final fun component2 ()Lcom/agentclientprotocol/model/AgentCapabilities;
 	public final fun component3 ()Ljava/util/List;
-	public final fun component4 ()Lkotlinx/serialization/json/JsonElement;
-	public final fun copy (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/InitializeResponse;
-	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/InitializeResponse;ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/InitializeResponse;
+	public final fun component4 ()Lcom/agentclientprotocol/model/Implementation;
+	public final fun component5 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/InitializeResponse;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/InitializeResponse;ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/InitializeResponse;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getAgentCapabilities ()Lcom/agentclientprotocol/model/AgentCapabilities;
+	public final fun getAgentInfo ()Lcom/agentclientprotocol/model/Implementation;
 	public final fun getAuthMethods ()Ljava/util/List;
 	public final fun getProtocolVersion ()I
 	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
@@ -1964,6 +2020,35 @@ public final class com/agentclientprotocol/model/Role$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
+public final class com/agentclientprotocol/model/SessionCapabilities : com/agentclientprotocol/model/AcpWithMeta {
+	public static final field Companion Lcom/agentclientprotocol/model/SessionCapabilities$Companion;
+	public fun <init> ()V
+	public fun <init> (Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/SessionCapabilities;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/SessionCapabilities;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/SessionCapabilities;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
+public final synthetic class com/agentclientprotocol/model/SessionCapabilities$$serializer : kotlinx/serialization/internal/GeneratedSerializer {
+	public static final field INSTANCE Lcom/agentclientprotocol/model/SessionCapabilities$$serializer;
+	public final fun childSerializers ()[Lkotlinx/serialization/KSerializer;
+	public final fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Lcom/agentclientprotocol/model/SessionCapabilities;
+	public synthetic fun deserialize (Lkotlinx/serialization/encoding/Decoder;)Ljava/lang/Object;
+	public final fun getDescriptor ()Lkotlinx/serialization/descriptors/SerialDescriptor;
+	public final fun serialize (Lkotlinx/serialization/encoding/Encoder;Lcom/agentclientprotocol/model/SessionCapabilities;)V
+	public synthetic fun serialize (Lkotlinx/serialization/encoding/Encoder;Ljava/lang/Object;)V
+	public fun typeParametersSerializers ()[Lkotlinx/serialization/KSerializer;
+}
+
+public final class com/agentclientprotocol/model/SessionCapabilities$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
+}
+
 public final class com/agentclientprotocol/model/SessionId {
 	public static final field Companion Lcom/agentclientprotocol/model/SessionId$Companion;
 	public static final synthetic fun box-impl (Ljava/lang/String;)Lcom/agentclientprotocol/model/SessionId;
@@ -2724,14 +2809,17 @@ public final class com/agentclientprotocol/model/ToolCallContent$Diff$Companion
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
-public final class com/agentclientprotocol/model/ToolCallContent$Terminal : com/agentclientprotocol/model/ToolCallContent {
+public final class com/agentclientprotocol/model/ToolCallContent$Terminal : com/agentclientprotocol/model/ToolCallContent, com/agentclientprotocol/model/AcpWithMeta {
 	public static final field Companion Lcom/agentclientprotocol/model/ToolCallContent$Terminal$Companion;
-	public fun <init> (Ljava/lang/String;)V
+	public fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ljava/lang/String;
-	public final fun copy (Ljava/lang/String;)Lcom/agentclientprotocol/model/ToolCallContent$Terminal;
-	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/ToolCallContent$Terminal;Ljava/lang/String;ILjava/lang/Object;)Lcom/agentclientprotocol/model/ToolCallContent$Terminal;
+	public final fun component2 ()Lkotlinx/serialization/json/JsonElement;
+	public final fun copy (Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;)Lcom/agentclientprotocol/model/ToolCallContent$Terminal;
+	public static synthetic fun copy$default (Lcom/agentclientprotocol/model/ToolCallContent$Terminal;Ljava/lang/String;Lkotlinx/serialization/json/JsonElement;ILjava/lang/Object;)Lcom/agentclientprotocol/model/ToolCallContent$Terminal;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getTerminalId ()Ljava/lang/String;
+	public fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;
 }
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/annotations/UnstableApi.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/annotations/UnstableApi.kt
new file mode 100644
index 0000000..9caf2b5
--- /dev/null
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/annotations/UnstableApi.kt
@@ -0,0 +1,8 @@
+package com.agentclientprotocol.annotations
+
+@RequiresOptIn(
+    message = "This API is unstable and may change in the future",
+    level = RequiresOptIn.Level.WARNING
+)
+@Retention(AnnotationRetention.BINARY)
+public annotation class UnstableApi()
\ No newline at end of file
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/AcpCreatedSessionResponse.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/AcpCreatedSessionResponse.kt
index af43fbe..91dcccf 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/AcpCreatedSessionResponse.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/AcpCreatedSessionResponse.kt
@@ -1,6 +1,9 @@
 package com.agentclientprotocol.model
 
+import com.agentclientprotocol.annotations.UnstableApi
+
 public interface AcpCreatedSessionResponse : AcpWithMeta {
     public val modes: SessionModeState?
+    @UnstableApi
     public val models: SessionModelState?
 }
\ No newline at end of file
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Capabilities.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Capabilities.kt
index f069095..a06c3e7 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Capabilities.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Capabilities.kt
@@ -61,6 +61,16 @@ public data class McpCapabilities(
     override val _meta: JsonElement? = null
 ) : AcpWithMeta
 
+/**
+ * Session capabilities supported by the agent.
+ *
+ * Currently empty but extensible for future session-related capabilities.
+ */
+@Serializable
+public data class SessionCapabilities(
+    override val _meta: JsonElement? = null
+) : AcpWithMeta
+
 /**
  * Capabilities supported by the agent.
  *
@@ -74,5 +84,6 @@ public data class AgentCapabilities(
     @EncodeDefault val loadSession: Boolean = false,
     @EncodeDefault val promptCapabilities: PromptCapabilities = PromptCapabilities(),
     @EncodeDefault val mcpCapabilities: McpCapabilities = McpCapabilities(),
+    @EncodeDefault val sessionCapabilities: SessionCapabilities = SessionCapabilities(),
     override val _meta: JsonElement? = null
 ) : AcpCapabilities, AcpWithMeta
\ No newline at end of file
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Methods.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Methods.kt
index b5eadf8..e39fb2a 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Methods.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Methods.kt
@@ -2,6 +2,7 @@
 
 package com.agentclientprotocol.model
 
+import com.agentclientprotocol.annotations.UnstableApi
 import com.agentclientprotocol.rpc.MethodName
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.builtins.serializer
@@ -50,6 +51,7 @@ public open class AcpMethod(public val methodName: MethodName) {
         public object SessionPrompt : AcpSessionRequestResponseMethod<PromptRequest, PromptResponse>("session/prompt", PromptRequest.serializer(), PromptResponse.serializer())
         public object SessionCancel : AcpSessionNotificationMethod<CancelNotification>("session/cancel", CancelNotification.serializer())
         public object SessionSetMode : AcpSessionRequestResponseMethod<SetSessionModeRequest, SetSessionModeResponse>("session/set_mode", SetSessionModeRequest.serializer(), SetSessionModeResponse.serializer())
+        @UnstableApi
         public object SessionSetModel : AcpSessionRequestResponseMethod<SetSessionModelRequest, SetSessionModelResponse>("session/set_model", SetSessionModelRequest.serializer(), SetSessionModelResponse.serializer())
     }
 
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Requests.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Requests.kt
index b976388..fd530d5 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Requests.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Requests.kt
@@ -3,6 +3,7 @@
 
 package com.agentclientprotocol.model
 
+import com.agentclientprotocol.annotations.UnstableApi
 import com.agentclientprotocol.rpc.RequestId
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.SerialName
@@ -168,6 +169,7 @@ public sealed class RequestPermissionOutcome {
 public data class InitializeRequest(
     val protocolVersion: ProtocolVersion,
     val clientCapabilities: ClientCapabilities = ClientCapabilities(),
+    val clientInfo: Implementation? = null,
     override val _meta: JsonElement? = null
 ) : AcpRequest
 
@@ -282,6 +284,7 @@ public data class SetSessionModeRequest(
  *
  * Request parameters for setting a session model.
  */
+@UnstableApi
 @Serializable
 public data class SetSessionModelRequest(
     override val sessionId: SessionId,
@@ -303,6 +306,7 @@ public data class InitializeResponse(
     val protocolVersion: ProtocolVersion,
     val agentCapabilities: AgentCapabilities = AgentCapabilities(),
     val authMethods: List<AuthMethod> = emptyList(),
+    val agentInfo: Implementation? = null,
     override val _meta: JsonElement? = null
 ) : AcpResponse
 
@@ -336,6 +340,7 @@ public data class SessionModeState(
  *
  * Information about a selectable model.
  */
+@UnstableApi
 @Serializable
 public data class ModelInfo(
     val modelId: ModelId,
@@ -351,6 +356,7 @@ public data class ModelInfo(
  *
  * The set of models and the one currently active.
  */
+@UnstableApi
 @Serializable
 public data class SessionModelState(
     val currentModelId: ModelId,
@@ -433,6 +439,7 @@ public data class SetSessionModeResponse(
  *
  * Response to `session/set_model` method.
  */
+@UnstableApi
 @Serializable
 public data class SetSessionModelResponse(
     override val _meta: JsonElement? = null
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/SessionUpdate.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/SessionUpdate.kt
index a0779cd..7d08430 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/SessionUpdate.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/SessionUpdate.kt
@@ -12,10 +12,23 @@ import kotlinx.serialization.json.JsonElement
 /**
  * Input specification for a command.
  *
- * [hint] All text that was typed after the command name is provided as input.
+ * Specifies how the agent should collect input for this command.
  */
 @Serializable
-public data class AvailableCommandInput(val hint: String)
+@JsonClassDiscriminator("type")
+public sealed class AvailableCommandInput {
+    /**
+     * All text typed after the command name is provided as unstructured input.
+     *
+     * @param hint A hint to display when input hasn't been provided yet
+     */
+    @Serializable
+    @SerialName("unstructured")
+    public data class Unstructured(
+        val hint: String,
+        override val _meta: JsonElement? = null
+    ) : AvailableCommandInput(), AcpWithMeta
+}
 
 /**
  * Information about a command.
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Terminal.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Terminal.kt
index cf5417b..3dc7ade 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Terminal.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Terminal.kt
@@ -7,9 +7,8 @@ import kotlinx.serialization.json.JsonElement
 
 /**
  * Terminal-related request and response types.
- * 
- * **UNSTABLE**: These types are not part of the spec yet,
- * and may be removed or changed at any point.
+ *
+ * See protocol docs: [Terminal](https://agentclientprotocol.com/protocol/terminal)
  */
 
 /**
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/ToolCall.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/ToolCall.kt
index 9b51bd1..5b2a9c4 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/ToolCall.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/ToolCall.kt
@@ -95,6 +95,7 @@ public sealed class ToolCallContent {
     @Serializable
     @SerialName("terminal")
     public data class Terminal(
-        val terminalId: String
-    ) : ToolCallContent()
+        val terminalId: String,
+        override val _meta: JsonElement? = null
+    ) : ToolCallContent(), AcpWithMeta
 }
\ No newline at end of file
diff --git a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Types.kt b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Types.kt
index 4525d8c..6d74cb5 100644
--- a/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Types.kt
+++ b/acp-model/src/commonMain/kotlin/com/agentclientprotocol/model/Types.kt
@@ -2,7 +2,7 @@
 
 package com.agentclientprotocol.model
 
-import kotlinx.serialization.ExperimentalSerializationApi
+import com.agentclientprotocol.annotations.UnstableApi
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.JsonElement
@@ -81,6 +81,7 @@ public value class SessionModeId(public val value: String) {
  *
  * A unique identifier for a model.
  */
+@UnstableApi
 @JvmInline
 @Serializable
 public value class ModelId(public val value: String) {
@@ -96,6 +97,19 @@ public enum class Role {
     @SerialName("user") USER
 }
 
+/**
+ * Describes the name and version of an ACP implementation.
+ *
+ * Used by both clients and agents to identify themselves during initialization.
+ */
+@Serializable
+public data class Implementation(
+    val name: String,
+    val version: String,
+    val title: String? = null,
+    override val _meta: JsonElement? = null
+) : AcpWithMeta
+
 /**
  * Optional annotations for the client. The client can use annotations to inform how objects are used or displayed.
  */
diff --git a/acp/api/acp.api b/acp/api/acp.api
index 8e48abd..63ffec5 100644
--- a/acp/api/acp.api
+++ b/acp/api/acp.api
@@ -9,10 +9,11 @@ public final class com/agentclientprotocol/agent/Agent {
 
 public final class com/agentclientprotocol/agent/AgentInfo {
 	public fun <init> ()V
-	public fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;)V
-	public synthetic fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (ILcom/agentclientprotocol/model/AgentCapabilities;Ljava/util/List;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun getAuthMethods ()Ljava/util/List;
 	public final fun getCapabilities ()Lcom/agentclientprotocol/model/AgentCapabilities;
+	public final fun getImplementation ()Lcom/agentclientprotocol/model/Implementation;
 	public final fun getProtocolVersion ()I
 	public final fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 }
@@ -78,9 +79,10 @@ public final class com/agentclientprotocol/client/Client {
 
 public final class com/agentclientprotocol/client/ClientInfo {
 	public fun <init> ()V
-	public fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;)V
-	public synthetic fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;)V
+	public synthetic fun <init> (ILcom/agentclientprotocol/model/ClientCapabilities;Lcom/agentclientprotocol/model/Implementation;Lkotlinx/serialization/json/JsonElement;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun getCapabilities ()Lcom/agentclientprotocol/model/ClientCapabilities;
+	public final fun getImplementation ()Lcom/agentclientprotocol/model/Implementation;
 	public final fun getProtocolVersion ()I
 	public final fun get_meta ()Lkotlinx/serialization/json/JsonElement;
 }
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/Agent.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/Agent.kt
index cc27067..3a33082 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/Agent.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/Agent.kt
@@ -120,12 +120,12 @@ public class Agent(
     private fun setHandlers(protocol: Protocol) {
         // Set up request handlers for incoming client requests
         protocol.setRequestHandler(AcpMethod.AgentMethods.Initialize) { params: InitializeRequest ->
-            val clientInfo = ClientInfo(params.protocolVersion, params.clientCapabilities, params._meta)
+            val clientInfo = ClientInfo(params.protocolVersion, params.clientCapabilities, params.clientInfo, params._meta)
             _clientInfo.complete(clientInfo)
             val agentInfo = agentSupport.initialize(clientInfo)
             // see https://agentclientprotocol.com/protocol/initialization#version-negotiation
             val negotiatedVersion = min(params.protocolVersion, agentInfo.protocolVersion)
-            return@setRequestHandler InitializeResponse(negotiatedVersion, agentInfo.capabilities, agentInfo.authMethods, agentInfo._meta)
+            return@setRequestHandler InitializeResponse(negotiatedVersion, agentInfo.capabilities, agentInfo.authMethods, agentInfo.implementation, agentInfo._meta)
         }
 
         protocol.setRequestHandler(AcpMethod.AgentMethods.Authenticate) { params: AuthenticateRequest ->
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentInfo.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentInfo.kt
index ea4e5af..92ef361 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentInfo.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentInfo.kt
@@ -2,6 +2,7 @@ package com.agentclientprotocol.agent
 
 import com.agentclientprotocol.model.AgentCapabilities
 import com.agentclientprotocol.model.AuthMethod
+import com.agentclientprotocol.model.Implementation
 import com.agentclientprotocol.model.LATEST_PROTOCOL_VERSION
 import com.agentclientprotocol.model.ProtocolVersion
 import kotlinx.serialization.json.JsonElement
@@ -10,5 +11,6 @@ public class AgentInfo(
     public val protocolVersion: ProtocolVersion = LATEST_PROTOCOL_VERSION,
     public val capabilities: AgentCapabilities = AgentCapabilities(),
     public val authMethods: List<AuthMethod> = emptyList(),
+    public val implementation: Implementation? = null,
     public val _meta: JsonElement? = null
 )
\ No newline at end of file
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentSession.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentSession.kt
index e92cd70..a29f258 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentSession.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/agent/AgentSession.kt
@@ -1,5 +1,6 @@
 package com.agentclientprotocol.agent
 
+import com.agentclientprotocol.annotations.UnstableApi
 import com.agentclientprotocol.common.Event
 import com.agentclientprotocol.model.*
 import kotlinx.coroutines.flow.Flow
@@ -45,23 +46,27 @@ public interface AgentSession {
     /**
      * Return a set of available models for the session. If the session doesn't support models, return an empty list.
      */
+    @UnstableApi
     public val availableModels: List<ModelInfo>
         get() = emptyList()
 
     /**
      * Return the default model for the session. The method is called only if [availableModels] returns a non-empty list.
      */
+    @UnstableApi
     public val defaultModel: ModelId
         get() = throw NotImplementedError("Must be implemented when providing non-empty ${::availableModels.name}")
 
     /**
      * Called when a client asks to change model. If the model is changed [SessionUpdate.CurrentModelUpdate] must be sent to the client.
      */
+    @UnstableApi
     public suspend fun setModel(modelId: ModelId, _meta: JsonElement?): SetSessionModelResponse {
         throw NotImplementedError("Must be implemented when providing non-empty ${::availableModels.name}")
     }
 }
 
+@UnstableApi
 internal fun AgentSession.asModelState(): SessionModelState? {
     val models = availableModels
     if (models.isEmpty()) return null
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/Client.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/Client.kt
index a38f87f..0841b58 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/Client.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/Client.kt
@@ -138,8 +138,8 @@ public class Client(
 
     public suspend fun initialize(clientInfo: ClientInfo, _meta: JsonElement? = null): AgentInfo {
         _clientInfo.complete(clientInfo)
-        val initializeResponse = AcpMethod.AgentMethods.Initialize(protocol, InitializeRequest(clientInfo.protocolVersion, clientInfo.capabilities, _meta))
-        val agentInfo = AgentInfo(initializeResponse.protocolVersion, initializeResponse.agentCapabilities, initializeResponse.authMethods, initializeResponse._meta)
+        val initializeResponse = AcpMethod.AgentMethods.Initialize(protocol, InitializeRequest(clientInfo.protocolVersion, clientInfo.capabilities, clientInfo.implementation, _meta))
+        val agentInfo = AgentInfo(initializeResponse.protocolVersion, initializeResponse.agentCapabilities, initializeResponse.authMethods, initializeResponse.agentInfo, initializeResponse._meta)
         _agentInfo.complete(agentInfo)
         return agentInfo
     }
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientInfo.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientInfo.kt
index c4f31ac..1347a27 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientInfo.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientInfo.kt
@@ -1,6 +1,7 @@
 package com.agentclientprotocol.client
 
 import com.agentclientprotocol.model.ClientCapabilities
+import com.agentclientprotocol.model.Implementation
 import com.agentclientprotocol.model.LATEST_PROTOCOL_VERSION
 import com.agentclientprotocol.model.ProtocolVersion
 import kotlinx.serialization.json.JsonElement
@@ -8,5 +9,6 @@ import kotlinx.serialization.json.JsonElement
 public class ClientInfo(
     public val protocolVersion: ProtocolVersion = LATEST_PROTOCOL_VERSION,
     public val capabilities: ClientCapabilities = ClientCapabilities(),
+    public val implementation: Implementation? = null,
     public val _meta: JsonElement? = null
 )
\ No newline at end of file
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSession.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSession.kt
index 26737b3..0c2564e 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSession.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSession.kt
@@ -1,5 +1,6 @@
 package com.agentclientprotocol.client
 
+import com.agentclientprotocol.annotations.UnstableApi
 import com.agentclientprotocol.common.ClientSessionOperations
 import com.agentclientprotocol.common.Event
 import com.agentclientprotocol.common.SessionCreationParameters
@@ -53,11 +54,13 @@ public interface ClientSession {
     /**
      * The flag indicates whether the agent supports the session model changing.
      */
+    @UnstableApi
     public val modelsSupported: Boolean
 
     /**
      * Returns a list of available models. Returns an empty list if the model changing is not supported.
      */
+    @UnstableApi
     public val availableModels: List<ModelInfo>
 
     /**
@@ -65,10 +68,12 @@ public interface ClientSession {
      *
      * @throws IllegalStateException if the model changing is not supported.
      */
+    @UnstableApi
     public val currentModel: StateFlow<ModelId>
 
     /**
      * Changes the session model to the specified model. The real change will be reported by an agent via [currentModel] and [ClientSessionOperations.notify].
      */
+    @UnstableApi
     public suspend fun setModel(modelId: ModelId, _meta: JsonElement? = null): SetSessionModelResponse
 }
\ No newline at end of file
diff --git a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSessionImpl.kt b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSessionImpl.kt
index cd3f268..bd2135e 100644
--- a/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSessionImpl.kt
+++ b/acp/src/commonMain/kotlin/com/agentclientprotocol/client/ClientSessionImpl.kt
@@ -1,5 +1,6 @@
 package com.agentclientprotocol.client
 
+import com.agentclientprotocol.annotations.UnstableApi
 import com.agentclientprotocol.common.ClientSessionOperations
 import com.agentclientprotocol.common.Event
 import com.agentclientprotocol.common.SessionCreationParameters
@@ -41,6 +42,7 @@ internal class ClientSessionImpl(
         MutableStateFlow(modes.currentModeId)
     }
 
+    @UnstableApi
     private val _currentModel by lazy {
         val models = createdResponse.models ?: error("Models are not provided by the agent")
         MutableStateFlow(models.currentModelId)
@@ -98,15 +100,19 @@ internal class ClientSessionImpl(
         return AcpMethod.AgentMethods.SessionSetMode(protocol, SetSessionModeRequest(sessionId, modeId, _meta))
     }
 
+    @UnstableApi
     override val modelsSupported: Boolean
         get() = createdResponse.models != null
 
+    @UnstableApi
     override val availableModels: List<ModelInfo>
         get() = createdResponse.models?.availableModels ?: emptyList()
 
+    @UnstableApi
     override val currentModel: StateFlow<ModelId>
         get() = _currentModel
 
+    @UnstableApi
     override suspend fun setModel(modelId: ModelId, _meta: JsonElement?): SetSessionModelResponse {
         return AcpMethod.AgentMethods.SessionSetModel(protocol, SetSessionModelRequest(sessionId, modelId, _meta))
     }
diff --git a/build.gradle.kts b/build.gradle.kts
index fe09ff3..7086053 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 private val buildNumber: String? = System.getenv("GITHUB_RUN_NUMBER")
 private val isReleasePublication = System.getenv("RELEASE_PUBLICATION")?.toBoolean() ?: false
 
-private val baseVersion = "0.7.3"
+private val baseVersion = "0.8.0"
 
 allprojects {
     group = "com.agentclientprotocol"