diff --git a/api-cli/package.json b/api-cli/package.json
index e6bbf57cd4..5d8e64c3dc 100644
--- a/api-cli/package.json
+++ b/api-cli/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@useoptic/cli",
   "description": "Optic's open source tool for building APIs that document & test themselves",
-  "version": "6.5.0",
+  "version": "6.5.1",
   "author": "@useoptic",
   "bin": {
     "api": "./bin/run"
diff --git a/api-cli/src/Paths.ts b/api-cli/src/Paths.ts
index 3a693c2fd5..41879fd7ce 100644
--- a/api-cli/src/Paths.ts
+++ b/api-cli/src/Paths.ts
@@ -3,7 +3,7 @@ import * as findUp from 'find-up'
 import * as fs from 'fs-extra'
 
 export interface IPathMapping {
-  
+
 }
 export async function getPaths(fallbackPath: (cwd: string) => string = (cwd) => path.join(cwd, '.api')) {
   const rootPath = await (async () => {
@@ -13,7 +13,7 @@ export async function getPaths(fallbackPath: (cwd: string) => string = (cwd) =>
     }
     return fallbackPath(process.cwd())
   })()
-  
+
   await fs.ensureDir(rootPath)
   process.chdir(path.resolve(rootPath, '../'))
 
@@ -31,7 +31,7 @@ async function getPathsRelativeToCwd(cwd: string): Promise<IPathMapping> {
   const exampleRequestsPath = path.join(basePath, 'example-requests')
   await fs.ensureDir(sessionsPath)
   await fs.ensureDir(exampleRequestsPath)
-  const outputPath = path.join(basePath, 'output')
+  const outputPath = path.join(basePath, 'generated')
 
   return {
     cwd,
@@ -44,4 +44,4 @@ async function getPathsRelativeToCwd(cwd: string): Promise<IPathMapping> {
     exampleRequestsPath,
     outputPath
   }
-}
\ No newline at end of file
+}
diff --git a/api-cli/src/commands/generate.ts b/api-cli/src/commands/generate.ts
deleted file mode 100644
index ad9d8c23b5..0000000000
--- a/api-cli/src/commands/generate.ts
+++ /dev/null
@@ -1,70 +0,0 @@
-import {Command, flags} from '@oclif/command'
-import * as fs from 'fs-extra'
-import * as clipboardy from 'clipboardy'
-// @ts-ignore
-import * as niceTry from 'nice-try'
-import * as path from 'path'
-// @ts-ignore
-import cli from 'cli-ux'
-// @ts-ignore
-import * as fetch from 'node-fetch'
-import {getPaths} from '../Paths'
-import {prepareEvents} from '../PersistUtils'
-import * as yaml from 'js-yaml'
-import analytics from '../lib/analytics'
-
-export default class Generate extends Command {
-
-  static description = 'generate something useful from your API spec'
-
-  static flags = {
-    // output: flags.string()
-  }
-
-  static args = [
-    {name: 'buildId', description: 'what do you want to generate?', required: true}
-  ]
-
-  async run() {
-    const {flags, args} = this.parse(Generate)
-    const {buildId} = args
-
-    if (flags.output) {
-      analytics.track('init from web')
-    }
-    // @ts-ignore
-    const {outputPath, specStorePath} = await getPaths()
-
-    if (buildId === 'oas') {
-
-      const fileContents = niceTry(() => fs.readFileSync(specStorePath).toString()) || '[]'
-      cli.action.start('Generating OAS file')
-
-      // @ts-ignore
-      const response = await fetch('https://ayiz1s0f8f.execute-api.us-east-2.amazonaws.com/production/oas/generate', {
-        method: 'POST',
-        headers: {
-          Accept: 'application/json',
-          'Content-Type': 'application/json'
-        },
-        body: JSON.stringify({fileContents})
-      })
-
-      if (response.status === 200) {
-        const oasJson = await response.json()
-        fs.ensureDirSync(outputPath)
-        cli.action.stop('done')
-        const oasPath = path.join(outputPath, 'oas.json')
-        fs.writeFileSync(path.join(outputPath, 'oas.json'), JSON.stringify(oasJson, null, 2))
-        this.log('Writing OAS file to: ' + oasPath)
-        return oasPath
-
-      } else {
-        return this.error('OAS Export Error' + await response.text())
-      }
-    } else {
-      this.error(`No build exists for ${buildId}`)
-    }
-
-  }
-}
diff --git a/api-cli/src/commands/generate/oas.ts b/api-cli/src/commands/generate/oas.ts
new file mode 100644
index 0000000000..c35f3747ba
--- /dev/null
+++ b/api-cli/src/commands/generate/oas.ts
@@ -0,0 +1,65 @@
+import {Command, flags} from '@oclif/command'
+import * as fs from 'fs-extra'
+import * as clipboardy from 'clipboardy'
+// @ts-ignore
+import * as niceTry from 'nice-try'
+import * as path from 'path'
+// @ts-ignore
+import * as opticEngine from '../../../provided/domain.js'
+import cli from 'cli-ux'
+// @ts-ignore
+import * as fetch from 'node-fetch'
+import {getPaths} from '../../Paths'
+import {prepareEvents} from '../../PersistUtils'
+import analytics from '../../lib/analytics'
+import * as yaml from 'js-yaml'
+
+
+export default class GenerateOas extends Command {
+
+  static description = 'export an OpenAPI 3.1 spec'
+
+  static flags = {
+    json: flags.boolean(),
+    yaml: flags.boolean(),
+  }
+
+  async run() {
+
+    const {flags} = this.parse(GenerateOas)
+    // @ts-ignore
+    const {outputPath, specStorePath} = await getPaths()
+
+    const oasGenerator = opticEngine.com.seamless.contexts.rfc.projections.OASProjectionHelper()
+
+    const fileContents = niceTry(() => fs.readFileSync(specStorePath).toString()) || '[]'
+    cli.action.start('Generating OAS file')
+
+    try {
+      const specAsJson = oasGenerator.fromEventString(fileContents)
+
+      const writeJson = flags.json || (!flags.json && !flags.yaml)
+      const writeYaml = flags.yaml
+
+      cli.action.stop('Done!')
+
+      if (writeJson) {
+        fs.ensureDirSync(outputPath)
+        const oasPath = path.join(outputPath, 'openapi.json')
+        fs.writeFileSync(path.join(outputPath, 'openapi.json'), JSON.stringify(specAsJson, null, 2))
+        return this.log('OpenAPI written to ' + oasPath)
+      }
+
+      if (writeYaml) {
+        fs.ensureDirSync(outputPath)
+        const oasPath = path.join(outputPath, 'openapi.yaml')
+        fs.writeFileSync(path.join(outputPath, 'openapi.yaml'), yaml.safeDump(specAsJson, {indent: 1}))
+        return this.log('OpenAPI written to ' + oasPath)
+      }
+
+    } catch (e) {
+      console.error('Error generating OpenAPI ')
+      console.log(e)
+    }
+  }
+}
diff --git a/api-cli/src/commands/publish-oas.ts b/api-cli/src/commands/publish-oas.ts
index 541d221b85..269be9fa94 100644
--- a/api-cli/src/commands/publish-oas.ts
+++ b/api-cli/src/commands/publish-oas.ts
@@ -10,7 +10,7 @@ import cli from 'cli-ux'
 import * as fetch from 'node-fetch'
 import {fromOptic} from '../lib/log-helper'
 import * as colors from 'colors'
-import Generate from './generate'
+import Oas from './generate/oas'
 import {exec, spawn, SpawnOptions} from 'child_process'
 import Init from './init'
 import {processSetting, readApiConfig} from './start'
@@ -37,7 +37,7 @@ export default class PublishOas extends Command {
       return this.error('No command registered for `publish-oas`. Add one to your api.yml file')
     }
 
-    const generated = await Generate.run(['oas'])
+    const generated = await Oas.run(['oas'])
     if (generated) {
       console.log(generated)
       const commandToRun = processSetting(publishOasCommand, {OAS_PATH: generated})
diff --git a/api-cli/tsconfig.tsbuildinfo b/api-cli/tsconfig.tsbuildinfo
index be0455c479..c268293a6d 100644
--- a/api-cli/tsconfig.tsbuildinfo
+++ b/api-cli/tsconfig.tsbuildinfo
@@ -326,7 +326,7 @@
         "signature": "aca36e2d27783f4bad7fc1786a532ff76024f0fc8575df48bcd9a5eb452fe7e7"
       },
       "./src/paths.ts": {
-        "version": "cb8220ef6e1c6dcb45904a596b5df5f905674a71a7032a3e986499c522bdf8cd",
+        "version": "b769654f69bd018154204952ed7b46a249c225eadfe6b80fd45902e31c28a7c2",
         "signature": "3c6be598c4405724e8ed2c5bd640c27341b23c15c654ad8943a37100271ede6f"
       },
       "./src/persistutils.ts": {
@@ -421,6 +421,10 @@
         "version": "b48640c615edeac46a37fa4c3f9427539c7b0c9c9dced07d374dcec44fc4ffb7",
         "signature": "b48640c615edeac46a37fa4c3f9427539c7b0c9c9dced07d374dcec44fc4ffb7"
       },
+      "./node_modules/colors/index.d.ts": {
+        "version": "a17e831d16c27cbe4d6f0bb238c1ded0d4a26c282009e431c68733be0b792f4f",
+        "signature": "a17e831d16c27cbe4d6f0bb238c1ded0d4a26c282009e431c68733be0b792f4f"
+      },
       "./node_modules/@oclif/errors/lib/handle.d.ts": {
         "version": "207218b7704a71e718a25a35101afb2206581fd07c878c34540038639ad2759e",
         "signature": "207218b7704a71e718a25a35101afb2206581fd07c878c34540038639ad2759e"
@@ -505,14 +509,6 @@
         "version": "72b62584101abbf031fd6e73a21842a99877186d422cb9e65aa470c2b98463f4",
         "signature": "60b33bcb9810f8e80f30a186b41f25d05b97a7781cf8f03edb9315d17a7aeaf1"
       },
-      "./src/commands/generate.ts": {
-        "version": "017f9750f51931f278a1fe68425c674d64372bec942b3d3e30cdef285ca00a71",
-        "signature": "f6be6a1f6937bf42d3b2190e690070d2721913b5f162a1a359c189175d932696"
-      },
-      "./node_modules/colors/index.d.ts": {
-        "version": "a17e831d16c27cbe4d6f0bb238c1ded0d4a26c282009e431c68733be0b792f4f",
-        "signature": "a17e831d16c27cbe4d6f0bb238c1ded0d4a26c282009e431c68733be0b792f4f"
-      },
       "./node_modules/open/index.d.ts": {
         "version": "1d5adf522de176e09dcabab58740bce14bb99356fb6474f621a152461a5e4703",
         "signature": "1d5adf522de176e09dcabab58740bce14bb99356fb6474f621a152461a5e4703"
@@ -1161,8 +1157,12 @@
         "version": "0b0481c285c517664694fd9f2e7636dfcae7cafff4a54318d2c9453e61ed91b9",
         "signature": "02d804c0bb60cd4693267f760804c914bd4145db7c176ae1a70f346f0fa104fc"
       },
+      "./src/commands/generate/oas.ts": {
+        "version": "3f41d1d430eda1bcc52d60ce882522728679aacf461cc45fc53fdf52ac2275f7",
+        "signature": "7bbc3a0caebfd245e2b09fda2038ed29e8f8082081c2203ffe23b1f068eb0b10"
+      },
       "./src/commands/publish-oas.ts": {
-        "version": "f334103858999564b3d2cf5c64855f970401acfb14a93fef2e78caf4e6060e92",
+        "version": "c6342852cf3fb843ccabb1429845f0676bf7f4d6c1ec9472149038cbbb772976",
         "signature": "a5f91a172a7df9fb875aa8a83eee10175de0ff3ad2566ce4689b9ac27907615e"
       },
       "./node_modules/@types/anymatch/index.d.ts": {
@@ -1903,6 +1903,10 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
+      "./node_modules/colors/index.d.ts": [
+        "./node_modules/@types/node/util.d.ts",
+        "./node_modules/@types/node/ts3.2/util.d.ts"
+      ],
       "./node_modules/@oclif/errors/lib/handle.d.ts": [
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
@@ -2010,23 +2014,6 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
-      "./src/commands/generate.ts": [
-        "./node_modules/@oclif/command/lib/index.d.ts",
-        "./node_modules/@types/fs-extra/index.d.ts",
-        "./node_modules/clipboardy/index.d.ts",
-        "./node_modules/@types/node/path.d.ts",
-        "./node_modules/cli-ux/lib/index.d.ts",
-        "./src/paths.ts",
-        "./src/persistutils.ts",
-        "./node_modules/@types/js-yaml/index.d.ts",
-        "./src/lib/analytics.ts",
-        "./node_modules/@types/node/util.d.ts",
-        "./node_modules/@types/node/ts3.2/util.d.ts"
-      ],
-      "./node_modules/colors/index.d.ts": [
-        "./node_modules/@types/node/util.d.ts",
-        "./node_modules/@types/node/ts3.2/util.d.ts"
-      ],
       "./node_modules/open/index.d.ts": [
         "./node_modules/@types/node/child_process.d.ts",
         "./node_modules/@types/node/ts3.2/index.d.ts",
@@ -3335,6 +3322,19 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
+      "./src/commands/generate/oas.ts": [
+        "./node_modules/@oclif/command/lib/index.d.ts",
+        "./node_modules/@types/fs-extra/index.d.ts",
+        "./node_modules/clipboardy/index.d.ts",
+        "./node_modules/@types/node/path.d.ts",
+        "./node_modules/cli-ux/lib/index.d.ts",
+        "./src/paths.ts",
+        "./src/persistutils.ts",
+        "./src/lib/analytics.ts",
+        "./node_modules/@types/js-yaml/index.d.ts",
+        "./node_modules/@types/node/util.d.ts",
+        "./node_modules/@types/node/ts3.2/util.d.ts"
+      ],
       "./src/commands/publish-oas.ts": [
         "./node_modules/@oclif/command/lib/index.d.ts",
         "./node_modules/@types/fs-extra/index.d.ts",
@@ -3343,7 +3343,7 @@
         "./node_modules/cli-ux/lib/index.d.ts",
         "./src/lib/log-helper.ts",
         "./node_modules/colors/index.d.ts",
-        "./src/commands/generate.ts",
+        "./src/commands/generate/oas.ts",
         "./node_modules/@types/node/child_process.d.ts",
         "./src/commands/init.ts",
         "./src/commands/start.ts",
@@ -3720,6 +3720,13 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
+      "./src/commands/generate/oas.ts": [
+        "./node_modules/@oclif/parser/lib/flags.d.ts",
+        "./node_modules/@oclif/command/lib/index.d.ts"
+      ],
+      "./src/commands/publish-oas.ts": [
+        "./node_modules/@oclif/command/lib/index.d.ts"
+      ],
       "./src/commands/intercept.ts": [
         "./node_modules/@oclif/parser/lib/flags.d.ts",
         "./src/lib/proxy-capture-session.ts",
@@ -3742,16 +3749,10 @@
         "./src/lib/proxy-capture-session.ts",
         "./node_modules/@oclif/command/lib/index.d.ts"
       ],
-      "./src/commands/publish-oas.ts": [
-        "./node_modules/@oclif/command/lib/index.d.ts"
-      ],
       "./src/commands/init.ts": [
         "./node_modules/@oclif/parser/lib/flags.d.ts",
         "./node_modules/@oclif/command/lib/index.d.ts"
       ],
-      "./src/commands/generate.ts": [
-        "./node_modules/@oclif/command/lib/index.d.ts"
-      ],
       "./node_modules/@types/node/globals.d.ts": [
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
@@ -5439,10 +5440,6 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
-      "./node_modules/colors/index.d.ts": [
-        "./node_modules/@types/node/util.d.ts",
-        "./node_modules/@types/node/ts3.2/util.d.ts"
-      ],
       "./node_modules/keytar/keytar.d.ts": [
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
@@ -5539,6 +5536,10 @@
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
       ],
+      "./node_modules/colors/index.d.ts": [
+        "./node_modules/@types/node/util.d.ts",
+        "./node_modules/@types/node/ts3.2/util.d.ts"
+      ],
       "./node_modules/clipboardy/index.d.ts": [
         "./node_modules/@types/node/util.d.ts",
         "./node_modules/@types/node/ts3.2/util.d.ts"
@@ -5757,6 +5758,7 @@
       "./src/index.ts",
       "./src/typescript-overrides.d.ts",
       "./node_modules/clipboardy/index.d.ts",
+      "./node_modules/colors/index.d.ts",
       "./node_modules/@oclif/errors/lib/handle.d.ts",
       "./node_modules/@oclif/errors/lib/errors/cli.d.ts",
       "./node_modules/@oclif/errors/lib/errors/exit.d.ts",
@@ -5778,8 +5780,6 @@
       "./node_modules/keytar/keytar.d.ts",
       "./src/lib/credentials.ts",
       "./src/lib/analytics.ts",
-      "./src/commands/generate.ts",
-      "./node_modules/colors/index.d.ts",
       "./node_modules/open/index.d.ts",
       "./src/commands/init.ts",
       "./node_modules/@types/range-parser/index.d.ts",
@@ -5942,6 +5942,7 @@
       "./node_modules/mockttp/dist/main.d.ts",
       "./node_modules/@types/tmp/index.d.ts",
       "./src/commands/intercept.ts",
+      "./src/commands/generate/oas.ts",
       "./src/commands/publish-oas.ts",
       "./node_modules/@types/anymatch/index.d.ts",
       "./node_modules/@types/archy/index.d.ts",
diff --git a/domain/src/main/scala/com/seamless/contexts/rfc/projections/OASProjection.scala b/domain/src/main/scala/com/seamless/contexts/rfc/projections/OASProjection.scala
new file mode 100644
index 0000000000..396c7177a1
--- /dev/null
+++ b/domain/src/main/scala/com/seamless/contexts/rfc/projections/OASProjection.scala
@@ -0,0 +1,204 @@
+package com.seamless.contexts.rfc.projections
+
+import com.seamless.contexts.requests.Commands.{BodyDescriptor, ParameterizedPathComponentDescriptor, ShapedBodyDescriptor}
+import com.seamless.contexts.requests.{HttpRequest, HttpResponse}
+import com.seamless.contexts.rfc.Events.RfcEvent
+import com.seamless.contexts.rfc.projections.OASDomain.{Body, Operation, Path, PathParameter, Response}
+import com.seamless.contexts.rfc.{InMemoryQueries, RfcService, RfcServiceJSFacade, RfcState}
+import com.seamless.contexts.shapes.ShapesHelper
+import com.seamless.contexts.shapes.projections.JsonSchemaProjection
+import com.seamless.ddd.{AggregateId, InMemoryEventStore}
+import io.circe.Json
+import io.circe.scalajs.{convertJsToJson, convertJsonToJs}
+import scala.scalajs.js.annotation.{JSExport, JSExportAll}
+import scala.scalajs.js
+
+@JSExport
+@JSExportAll
+object OASProjectionHelper {
+  def fromEventString(eventString: String): js.Any = {
+    val eventStore = RfcServiceJSFacade.makeEventStore()
+    eventStore.bulkAdd("id", eventString)
+    val rfcService: RfcService = new RfcService(eventStore)
+    val queries = new InMemoryQueries(eventStore, rfcService, "id")
+    convertJsonToJs(new OASProjection(queries, rfcService, "id").generate)
+  }
+}
+
+class OASProjection(queries: InMemoryQueries, rfcService: RfcService, aggregateId: AggregateId) {
+
+  lazy val rfcState = rfcService.currentState(aggregateId)
+
+  lazy val sharedSchemaComponents = rfcState.shapesState.shapes.filter {
+    case (k, shape) => !shape.isRemoved && shape.descriptor.name != "" && !ShapesHelper.allCoreShapes.exists(_.baseShapeId == k)
+  }
+  lazy val pathMapping: Vector[FullPath] = PathListProjection.fromEvents(rfcService.listEvents("id"))
+
+  def bodyToOAS(bodyDescriptor: BodyDescriptor) = {
+    bodyDescriptor match {
+      case body: ShapedBodyDescriptor => Some(Body(body.httpContentType, Some(new JsonSchemaProjection(body.shapeId)(rfcState.shapesState).asJsonSchema(expand = false))))
+      case _ => None
+    }
+  }
+
+  def responsesForRequest(requestId: String): Vector[HttpResponse] = {
+    queries.requestsState.responses.collect {
+      case (responseId, response) if response.responseDescriptor.requestId == requestId && !response.isRemoved  => response
+    }.toVector.sortBy(_.responseDescriptor.httpStatusCode)
+  }
+
+
+  def getContributionOption(id: String, key: String) = queries.contributions.get(id, key)
+
+  def operationFromRequest(request: HttpRequest): Operation = {
+
+    val requestBody = bodyToOAS(request.requestDescriptor.bodyDescriptor)
+//
+    val operationId = getContributionOption(request.requestId, "oas.operationId").getOrElse(request.requestId)
+    val summary = getContributionOption(request.requestId, "oas.operationId")
+    val description = getContributionOption(request.requestId, "oas.operationId")
+
+    val r = responsesForRequest(request.requestId)
+    val responses = responsesForRequest(request.requestId).sortBy(_.responseDescriptor.httpStatusCode).map {
+      case res => {
+        val responseDescription = getContributionOption(res.responseId, "description")
+        (res.responseDescriptor.httpStatusCode.toString, Response(responseDescription, bodyToOAS(res.responseDescriptor.bodyDescriptor)))
+      }
+    }
+
+    Operation(operationId, summary, description, requestBody, responses)
+  }
+
+  lazy val oasOperations = {
+
+    def pathParametersForLeaf(id: String) = {
+      val searchPaths = pathMapping.find(_.pathId == id).get._parentPathIds :+ id
+      searchPaths.map(i => {
+        queries.requestsState.pathComponents(i).descriptor
+      }).collect {
+        //hardcoding string for now
+        case param: ParameterizedPathComponentDescriptor => PathParameter(param.name, Json.obj("type" -> Json.fromString("string")))
+      }
+    }
+
+    def requestForId(id: String) = {
+      queries.requestsState.requests(id)
+    }
+
+    val pathIdsWithRequests = queries.pathsWithRequests.values.toSet
+    pathIdsWithRequests.map(pathId => Path( pathMapping.find(_.pathId == pathId).get.absolutePath , {
+      queries.pathsWithRequests.collect { case i if i._2 == pathId && !requestForId(i._1).isRemoved =>
+        val request = requestForId(i._1)
+        request.requestDescriptor.httpMethod.toLowerCase -> operationFromRequest(request)
+      }.toVector.sortBy(_._1).toMap
+    }, pathParametersForLeaf(pathId)))
+  }
+
+
+  def generate: Json = {
+
+
+    val sharedDefinitions = sharedSchemaComponents.map(i => {
+      import com.seamless.contexts.shapes.projections.JsonSchemaHelpers._
+      val name = i._2.descriptor.name
+      name -> new JsonSchemaProjection(i._1)(rfcState.shapesState).asJsonSchema(expand = true)
+    }).toSeq
+
+    Json.obj(
+      "openapi" -> Json.fromString("3.0.1"),
+      "info" -> Json.obj(
+        "title" -> Json.fromString(queries.apiName()),
+        "version" -> Json.fromString(rfcService.listEvents("id").length.toString)
+      ),
+      "paths" -> Json.obj(
+        oasOperations.toVector.sortBy(_.absolutePath).map(path => {
+          path.absolutePath -> Json.obj(
+            (path.operations.toVector.sortBy(_._1).map { case (k, v) => k -> v.toJson } :+ path.pathParametersToJson ):_*
+          )
+        }):_*
+      ),
+      "components" -> Json.obj(
+        "schemas" -> Json.obj(
+          sharedDefinitions:_*
+        )
+      )
+    )
+
+  }
+
+}
+
+object OASDomain {
+
+  case class Path(absolutePath: String, operations: Map[String, Operation], pathParameters: Vector[PathParameter]) {
+    def pathParametersToJson = {
+      "parameters" -> Json.arr( pathParameters.sortBy(p => absolutePath.indexOf("{"+p+"}")).map(_.toJson):_*)
+    }
+  }
+  case class Operation(operationId: String,
+                       summary: Option[String],
+                       description: Option[String],
+                       requestBody: Option[Body],
+                       responses: Vector[(String, Response)])
+  {
+
+    def toJson = {
+      var json = Json.obj().asObject.get
+      json = json.add("operationId", Json.fromString(operationId))
+
+      if (summary.isDefined && summary.get.nonEmpty) {
+        json = json.add("purpose", Json.fromString(summary.get))
+      }
+      if (description.isDefined && description.get.nonEmpty) {
+        json = json.add("description", Json.fromString(description.get))
+      }
+
+      if (requestBody.isDefined) {
+        json = json.add("requestBody", requestBody.get.toJson)
+      }
+
+      if (responses.nonEmpty) {
+        json = json.add("responses", Json.obj( responses.map(i => (i._1, i._2.toJson)):_* ))
+      }
+
+      Json.fromJsonObject(json)
+    }
+
+  }
+
+  case class Body(contentType: String, asJsonSchema: Option[Json]) {
+    def toJson = {
+      Json.obj(
+        "content" -> Json.obj(
+          contentType -> Json.obj(
+            "schema" -> asJsonSchema.get
+          )
+        )
+      )
+    }
+  }
+
+  case class PathParameter(name: String, asJsonSchema: Json) {
+    def toJson = {
+      Json.obj(
+        "in" -> Json.fromString("path"),
+        "name" -> Json.fromString(name),
+        "required" -> Json.fromBoolean(true),
+        "schema" -> asJsonSchema
+      )
+    }
+  }
+
+  case class Response(description: Option[String], responseBody: Option[Body]) {
+    def toJson = {
+      val base = if (responseBody.isDefined) {
+        responseBody.get.toJson
+      } else {
+        Json.obj()
+      }
+      Json.fromJsonObject(base.asObject.get.add("description", Json.fromString(description.getOrElse(""))))
+    }
+  }
+
+
+}
diff --git a/domain/src/main/scala/com/seamless/contexts/rfc/projections/PathProjection.scala b/domain/src/main/scala/com/seamless/contexts/rfc/projections/PathProjection.scala
new file mode 100644
index 0000000000..6fbd18bb75
--- /dev/null
+++ b/domain/src/main/scala/com/seamless/contexts/rfc/projections/PathProjection.scala
@@ -0,0 +1,57 @@
+package com.seamless.contexts.rfc.projections
+
+import com.seamless.contexts.requests.Commands.PathComponentId
+import com.seamless.contexts.requests.Events.{PathComponentAdded, PathComponentRemoved, PathComponentRenamed, PathParameterAdded, PathParameterRemoved}
+import com.seamless.contexts.rfc.Events.RfcEvent
+import com.seamless.ddd.Projection
+
+case class FullPath(pathId: PathComponentId, isParameter: Boolean, _parentPathIds: Vector[PathComponentId], name: String, absolutePath: String, normalizedAbsolutePath: String)
+
+object PathListProjection extends Projection[RfcEvent, Vector[FullPath]] {
+
+  override def fromEvents(events: Vector[RfcEvent]): Vector[FullPath] = {
+    val pathMap: Map[PathComponentId, FullPath] = Map("root" -> FullPath("root", isParameter = false,Vector.empty, "", "/", "/"))
+    withMap(pathMap, events)
+  }
+
+  override def withInitialState(initialState: Vector[FullPath], events: Vector[RfcEvent]): Vector[FullPath] = {
+    val pathMap = initialState.map(item => item.pathId -> item).toMap
+    withMap(pathMap, events)
+  }
+
+  def joinPath(parentPath: String, pathComponent: String)  = {
+    if (parentPath == "/") parentPath + pathComponent else parentPath + "/" + pathComponent
+  }
+
+  def withMap(pathMap: Map[PathComponentId, FullPath], events: Vector[RfcEvent]): Vector[FullPath] = {
+    val results = events.foldLeft(pathMap)((acc, event) => {
+      event match {
+        case e: PathComponentAdded => {
+          val parent = acc(e.parentPathId)
+          acc + (e.pathId -> FullPath(e.pathId, isParameter = false, e.parentPathId +: parent._parentPathIds, e.name, joinPath(parent.absolutePath, e.name), joinPath(parent.normalizedAbsolutePath, e.name)))
+        }
+        case e: PathComponentRenamed => {
+          val p = acc(e.pathId)
+          acc.updated(e.pathId, p.copy(name = e.name))
+        }
+
+        case e: PathComponentRemoved => {
+          acc - e.pathId
+        }
+
+        case e: PathParameterAdded => {
+          val parent = acc(e.parentPathId)
+          acc + (e.pathId -> FullPath(e.pathId, isParameter = true, e.parentPathId +: parent._parentPathIds, e.name, joinPath(parent.absolutePath, "{" + e.name + "}"), joinPath(parent.normalizedAbsolutePath, "{" + e.name + "}")))
+        }
+
+        case e: PathParameterRemoved => {
+          acc - e.pathId
+        }
+
+        case _ => acc
+      }
+    })
+
+    results.values.toVector
+  }
+}
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/ShapesAggregate.scala b/domain/src/main/scala/com/seamless/contexts/shapes/ShapesAggregate.scala
index 041a00f1ad..ed44f501f7 100644
--- a/domain/src/main/scala/com/seamless/contexts/shapes/ShapesAggregate.scala
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/ShapesAggregate.scala
@@ -4,6 +4,7 @@ import com.seamless.contexts.base.BaseCommandContext
 import com.seamless.contexts.rfc.Events.{EventContext, fromCommandContext}
 import com.seamless.contexts.shapes.Commands._
 import com.seamless.contexts.shapes.Events._
+import com.seamless.contexts.shapes.ShapesHelper.OptionalKind
 import com.seamless.ddd.{Effects, EventSourcedAggregate}
 
 import scala.collection.immutable.ListMap
@@ -254,7 +255,7 @@ object ShapesAggregate extends EventSourcedAggregate[ShapesState, ShapesCommand,
     val oneOfShape = CoreShape(oneOfShapeId, DynamicParameterList(Seq.empty), "OneOf")
 
     val optionalShapeId = "$optional"
-    val optionalParameter = ShapeParameterEntity("$optionalInner", ShapeParameterValue(optionalShapeId, ProviderInShape(optionalShapeId, NoProvider(), "$optionalInner"), "T"), isRemoved = false)
+    val optionalParameter = ShapeParameterEntity(OptionalKind.innerParam, ShapeParameterValue(optionalShapeId, ProviderInShape(optionalShapeId, NoProvider(), OptionalKind.innerParam), "T"), isRemoved = false)
     val optionalShape = CoreShape(optionalShapeId, StaticParameterList(Seq(optionalParameter.shapeParameterId)), "Optional")
 
     val nullableShapeId = "$nullable"
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/ShapesHelper.scala b/domain/src/main/scala/com/seamless/contexts/shapes/ShapesHelper.scala
index c3dc84390a..5df6b854f5 100644
--- a/domain/src/main/scala/com/seamless/contexts/shapes/ShapesHelper.scala
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/ShapesHelper.scala
@@ -40,17 +40,17 @@ object ShapesHelper {
 
   sealed class CoreShapeKind(val baseShapeId: ShapeId, val name: String)
   case object ObjectKind extends CoreShapeKind("$object", "Object")
-  case object ListKind extends CoreShapeKind("$list", "List")
+  case object ListKind extends CoreShapeKind("$list", "List") {def innerParam: String = "$listItem"}
   case object MapKind extends CoreShapeKind("$map", "Map")
   case object OneOfKind extends CoreShapeKind("$oneOf", "One of")
   case object AnyKind extends CoreShapeKind("$any", "Any")
   case object StringKind extends CoreShapeKind("$string", "String")
   case object NumberKind extends CoreShapeKind("$number", "Number")
   case object BooleanKind extends CoreShapeKind("$boolean", "Boolean")
-  case object IdentifierKind extends CoreShapeKind("$identifier", "Identifier")
-  case object ReferenceKind extends CoreShapeKind("$reference", "Reference")
-  case object NullableKind extends CoreShapeKind("$nullable", "Nullable")
-  case object OptionalKind extends CoreShapeKind("$optional", "Optional")
+  case object IdentifierKind extends CoreShapeKind("$identifier", "Identifier") {def innerParam: String = "$identifierInner"}
+  case object ReferenceKind extends CoreShapeKind("$reference", "Reference") {def innerParam: String = "$referenceInner"}
+  case object NullableKind extends CoreShapeKind("$nullable", "Nullable") {def innerParam: String = "$nullableInner"}
+  case object OptionalKind extends CoreShapeKind("$optional", "Optional") {def innerParam: String = "$optionalInner"}
   case object UnknownKind extends CoreShapeKind("$unknown", "Unknown")
 
   val allCoreShapes = Set(ObjectKind, ListKind, MapKind, OneOfKind, AnyKind, StringKind, NumberKind, BooleanKind, IdentifierKind, ReferenceKind, NullableKind, OptionalKind, UnknownKind)
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/projections/ExampleProjection.scala b/domain/src/main/scala/com/seamless/contexts/shapes/projections/ExampleProjection.scala
index c8000705e6..aba1ddcbc2 100644
--- a/domain/src/main/scala/com/seamless/contexts/shapes/projections/ExampleProjection.scala
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/projections/ExampleProjection.scala
@@ -21,7 +21,7 @@ object ExampleProjection {
 
   private def flatPrimitive(kind: CoreShapeKind, value: String): FlatShape = {
     val nameComponent = ColoredComponent(value, "primitive", None, primitiveId = Some(kind.baseShapeId))
-    FlatShape(kind.baseShapeId, Seq(nameComponent), Seq(), kind.baseShapeId, canName = false)
+    FlatShape(kind.baseShapeId, Seq(nameComponent), Seq(), kind.baseShapeId, canName = false, Map.empty)
   }
 
   private def jsonToFlatRender(json: Json)(implicit path: Seq[String]): FlatShape = {
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/projections/FlatShapeProjection.scala b/domain/src/main/scala/com/seamless/contexts/shapes/projections/FlatShapeProjection.scala
index 7f093c7169..1c8645da21 100644
--- a/domain/src/main/scala/com/seamless/contexts/shapes/projections/FlatShapeProjection.scala
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/projections/FlatShapeProjection.scala
@@ -18,13 +18,13 @@ object FlatShapeProjection {
   @JSExportAll
   case class FlatField(fieldName: String, shape: FlatShape, fieldId: FieldId)
   @JSExportAll
-  case class FlatShape(baseShapeId: ShapeId, typeName: Seq[ColoredComponent], fields: Seq[FlatField], id: ShapeId, canName: Boolean) {
+  case class FlatShape(baseShapeId: ShapeId, typeName: Seq[ColoredComponent], fields: Seq[FlatField], id: ShapeId, canName: Boolean, links: Map[String, ShapeId]) {
     def joinedTypeName = typeName.map(_.name).mkString(" ")
   }
   @JSExportAll
   case class FlatShapeResult(root: FlatShape, parameterMap: Map[String, FlatShape], pathsForAffectedIds: Vector[Seq[String]])
 
-  private val returnAny = (AnyKind.baseShapeId, FlatShape(AnyKind.baseShapeId, Seq(ColoredComponent("Any", "primitive", primitiveId = Some(AnyKind.baseShapeId))), Seq.empty, "$any", false))
+  private val returnAny = (AnyKind.baseShapeId, FlatShape(AnyKind.baseShapeId, Seq(ColoredComponent("Any", "primitive", primitiveId = Some(AnyKind.baseShapeId))), Seq.empty, "$any", false, Map.empty))
 
   def forShapeId(shapeId: ShapeId, fieldIdOption: Option[String] = None, affectedIds: Seq[String] = Seq())(implicit shapesState: ShapesState, expandedName: Boolean = true) = {
     implicit val parametersByShapeId: mutable.Map[String, FlatShape] = scala.collection.mutable.HashMap[String, FlatShape]()
@@ -52,15 +52,15 @@ object FlatShapeProjection {
       .map(i => (i.shapeId, getFlatShape(i.shapeId, trail and InParameter(i.shapeId))(shapesState, None, false, parametersByShapeId, trailLogger)))
       .getOrElse(returnAny)
 
-    def returnWith( typeName: Seq[ColoredComponent], fields: Seq[FlatField] = Seq(), canName: Boolean = false ) = {
-      FlatShape(shape.baseShapeId, typeName, fields, shapeId, canName)
+    def returnWith( typeName: Seq[ColoredComponent], fields: Seq[FlatField] = Seq(), canName: Boolean = false, links: Map[String, ShapeId] ) = {
+      FlatShape(shape.coreShapeId, typeName, fields, shapeId, canName, links)
     }
 
     shape.coreShapeId match {
       case ListKind.baseShapeId => {
         val (innerShapeId, flatShape) = resolveInner("$listItem")
         addLinkToParameter(innerShapeId, flatShape)
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map("$listItem" -> innerShapeId))
       }
       case MapKind.baseShapeId => {
         val (keyInnerShapeId, keyFlatShape) = resolveInner("$mapKey")
@@ -69,7 +69,7 @@ object FlatShapeProjection {
         val (valueInnerShapeId, valueFlatShape) = resolveInner("$mapValue")
         addLinkToParameter(valueInnerShapeId, valueFlatShape)
 
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map("$mapKey" -> keyInnerShapeId, "$mapValue" -> valueInnerShapeId))
       }
       case OneOfKind.baseShapeId => {
         val inners = shapesState.shapes(shapeId).descriptor.parameters match {
@@ -81,28 +81,30 @@ object FlatShapeProjection {
           }
         }
 
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        val innerLinks = inners.map(resolveInner).map(_._1).zipWithIndex.map { case (innerId, index) => index.toString -> innerId }.toMap
+
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = innerLinks)
       }
       case NullableKind.baseShapeId => {
         val (innerShapeId, flatShape) = resolveInner("$nullableInner")
         addLinkToParameter(innerShapeId, flatShape)
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map("$nullableInner" -> innerShapeId))
       }
       case OptionalKind.baseShapeId => {
-        val (innerShapeId, flatShape) = resolveInner("$optionalInner")
+        val (innerShapeId, flatShape) = resolveInner(OptionalKind.innerParam)
         addLinkToParameter(innerShapeId, flatShape)
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map(OptionalKind.innerParam -> innerShapeId))
       }
       case ReferenceKind.baseShapeId => {
         val (innerShapeId, flatShape) = resolveInner("$referenceInner")
         addLinkToParameter(innerShapeId, flatShape)
 
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map("$referenceInner" -> innerShapeId))
       }
       case IdentifierKind.baseShapeId => {
         val (innerShapeId, flatShape) = resolveInner("$identifierInner")
         addLinkToParameter(innerShapeId, flatShape)
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map("$identifierInner" -> innerShapeId))
       }
       case ObjectKind.baseShapeId => {
         val baseObject = ShapeDiffer.resolveBaseObject(shapeId)(shapesState)
@@ -125,12 +127,12 @@ object FlatShapeProjection {
 //        })
 
 
-        FlatShape(baseObject.descriptor.baseShapeId, NameForShapeId.getShapeName(baseObject.shapeId), fields, baseObject.shapeId, canName)
+        FlatShape(baseObject.descriptor.baseShapeId, NameForShapeId.getShapeName(baseObject.shapeId), fields, baseObject.shapeId, canName, Map.empty)
       }
 
       //fallback to primitives
       case baseShapeId if ShapesHelper.allCoreShapes.exists(_.baseShapeId == baseShapeId) =>
-        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName))
+        returnWith(NameForShapeId.getShapeName(shapeId, expand = expandedName), links = Map.empty)
       //fallback for unhandled -- should never be reached
       case _ => returnAny._2
     }
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/projections/JsonSchemaProjection.scala b/domain/src/main/scala/com/seamless/contexts/shapes/projections/JsonSchemaProjection.scala
new file mode 100644
index 0000000000..17313e75fd
--- /dev/null
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/projections/JsonSchemaProjection.scala
@@ -0,0 +1,134 @@
+package com.seamless.contexts.shapes.projections
+
+import com.seamless.contexts.shapes.ShapesHelper.{BooleanKind, ListKind, MapKind, NullableKind, NumberKind, ObjectKind, OptionalKind, ReferenceKind, StringKind}
+import com.seamless.contexts.shapes.{ShapesHelper, ShapesState}
+import com.seamless.contexts.shapes.projections.FlatShapeProjection.{FlatShape, FlatShapeResult}
+import io.circe.Json
+import JsonSchemaHelpers._
+
+class JsonSchemaProjection(shapeId: String)(implicit shapesState: ShapesState) {
+
+  def asJsonSchema(expand: Boolean): Json = {
+    val flatShape = FlatShapeProjection.forShapeId(shapeId)(shapesState)
+    flatShapeToJsonSchema(flatShape.root, expand: Boolean)(flatShape)
+  }
+
+
+  private def flatShapeToJsonSchema(shape: FlatShape, expand: Boolean)(implicit projection: FlatShapeResult): Json = {
+    val schema = new JsonSchema
+    val isNamed = shapesState.shapes.get(shape.id).exists(_.descriptor.name != "")
+
+    if (isNamed && !expand) {
+      val name = shapesState.shapes(shape.id).descriptor.name
+      schema.addRef(("#/components/schemas/"+ name.toCamelCase).asJson)
+      return schema.asJson
+    }
+
+    if (isNamed && expand) {
+      val name = shapesState.shapes(shape.id).descriptor.name
+      schema.addTitle(name)
+    }
+
+    shape.baseShapeId match {
+      case ObjectKind.baseShapeId => {
+        schema.assignType("object".asJson)
+
+        val required = new scala.collection.mutable.ListBuffer[String]()
+        val fields = shape.fields.map { case field =>
+          val fieldName = field.fieldName
+          val fieldShape = flatShapeToJsonSchema(field.shape, expand = false)
+          if (field.shape.baseShapeId != OptionalKind.baseShapeId) {
+            required append fieldName
+          }
+          fieldName -> fieldShape
+        }
+        schema.addRequired(required.toList)
+        schema.addProperties(fields)
+      }
+
+      case ListKind.baseShapeId => {
+        schema.assignType("array".asJson)
+        val inner = shape.links(ListKind.innerParam)
+        schema.addItems(new JsonSchemaProjection(inner).asJsonSchema(expand = false))
+      }
+
+      case StringKind.baseShapeId => schema.assignType("string".asJson)
+      case NumberKind.baseShapeId => schema.assignType("number".asJson)
+      case BooleanKind.baseShapeId => schema.assignType("boolean".asJson)
+
+      case OptionalKind.baseShapeId => {
+        val inner = shape.links(OptionalKind.innerParam)
+        return new JsonSchemaProjection(inner).asJsonSchema(expand = false)
+      }
+
+      case MapKind.baseShapeId | ReferenceKind.baseShapeId | NullableKind.baseShapeId | OptionalKind.baseShapeId => {
+        println("Core shape not implemented "+  shape.baseShapeId)
+      }
+
+      case _ => {
+        println("OAS not implemented for type "+ shape.baseShapeId)
+      }
+    }
+
+    schema.asJson
+  }
+
+}
+
+object JsonSchemaHelpers {
+
+  implicit class IdiomaticJsonString(string: String) {
+    def asJson = Json.fromString(string)
+  }
+
+  implicit class StringHelpersImpl(s: String) {
+    def toCamelCase: String  = {
+      val split = s.split(" ")
+      val tail = split.tail.map { x => x.head.toUpper + x.tail }
+      split.head + tail.mkString
+    }
+  }
+
+  class JsonSchema {
+
+    private var _internal = Json.obj().asObject.get
+
+    def assignType(json: Json) = {
+      _internal = _internal.add("type", json)
+    }
+
+    def addTitle(name: String) = {
+      _internal = _internal.add("title", Json.fromString(name))
+    }
+
+    def addProperties(fields: Seq[(String, Json)]) = {
+      _internal = _internal.add("properties", Json.obj(fields: _*))
+    }
+    def addRequired(required: List[String]) = {
+      _internal = _internal.add("required", Json.arr(required.map(_.asJson):_*))
+    }
+
+    def addItems(json: Json) = {
+      _internal = _internal.add("items", json)
+    }
+
+    def addRef(json: Json) = {
+      _internal = _internal.add("$ref", json)
+    }
+
+    def allOf(innerSchemas: Seq[Json]) = {
+      _internal = Json.obj(
+        "allOf" -> Json.arr(innerSchemas: _*)
+      ).asObject.get
+    }
+
+    def description(string: String) = {
+      _internal = _internal.add("description", Json.fromString(string))
+    }
+
+    def replaceWith(json: Json) = _internal = json.asObject.get
+
+    def asJson = Json.fromJsonObject(_internal)
+  }
+
+}
diff --git a/domain/src/main/scala/com/seamless/contexts/shapes/projections/NameForShapeId.scala b/domain/src/main/scala/com/seamless/contexts/shapes/projections/NameForShapeId.scala
index 691d86152d..5883fc2019 100644
--- a/domain/src/main/scala/com/seamless/contexts/shapes/projections/NameForShapeId.scala
+++ b/domain/src/main/scala/com/seamless/contexts/shapes/projections/NameForShapeId.scala
@@ -84,7 +84,7 @@ object NameForShapeId {
         nullableInner ++ Seq(ColoredComponent("(nullable)", "modifier", primitiveId= Some(NullableKind.baseShapeId)))
       }
       case OptionalKind.baseShapeId => {
-        val (innerId, optionalInner) = resolveInner("$optionalInner")
+        val (innerId, optionalInner) = resolveInner(OptionalKind.innerParam)
         optionalInner ++ Seq(ColoredComponent("(optional)", "modifier", primitiveId= Some(OptionalKind.baseShapeId)))
       }
       case ReferenceKind.baseShapeId => {
diff --git a/domain/src/main/scala/com/seamless/diff/ShapeDiffer.scala b/domain/src/main/scala/com/seamless/diff/ShapeDiffer.scala
index 4ade74247a..c8e1aa9022 100644
--- a/domain/src/main/scala/com/seamless/diff/ShapeDiffer.scala
+++ b/domain/src/main/scala/com/seamless/diff/ShapeDiffer.scala
@@ -182,7 +182,7 @@ object ShapeDiffer {
         }
       }
       case OptionalKind => {
-        val referencedShape = resolveParameterShape(expectedShape.shapeId, "$optionalInner")
+        val referencedShape = resolveParameterShape(expectedShape.shapeId, OptionalKind.innerParam)
         if (referencedShape.isDefined) {
           ShapeDiffer.diff(referencedShape.get, actualShapeOption)
         } else {
diff --git a/domain/src/main/scala/com/seamless/diff/interpreters/OptionalInterpreter.scala b/domain/src/main/scala/com/seamless/diff/interpreters/OptionalInterpreter.scala
index 7dde80e966..d7a9c68017 100644
--- a/domain/src/main/scala/com/seamless/diff/interpreters/OptionalInterpreter.scala
+++ b/domain/src/main/scala/com/seamless/diff/interpreters/OptionalInterpreter.scala
@@ -63,7 +63,7 @@ class OptionalInterpreter(shapesState: ShapesState) extends Interpreter[RequestD
             case fs: FieldShapeFromShape => ShapeProvider(fs.shapeId)
             case fs: FieldShapeFromParameter => ParameterProvider(fs.shapeParameterId)
           },
-          "$optionalInner"
+          OptionalKind.innerParam
         )
       ),
       SetFieldShape(FieldShapeFromShape(field.fieldId, wrapperShapeId)),
@@ -83,7 +83,7 @@ class OptionalInterpreter(shapesState: ShapesState) extends Interpreter[RequestD
     val commands = Seq(
       AddShape(wrapperShapeId, OptionalKind.baseShapeId, ""),
       SetParameterShape(
-        ProviderInShape(wrapperShapeId, ShapeProvider(shapeDiff.expected.shapeId), "$optionalInner")
+        ProviderInShape(wrapperShapeId, ShapeProvider(shapeDiff.expected.shapeId), OptionalKind.innerParam)
       ),
       SetRequestBodyShape(requestDiffResult.requestId, ShapedBodyDescriptor(requestDiffResult.contentType, wrapperShapeId, isRemoved = false))
     )
@@ -102,7 +102,7 @@ class OptionalInterpreter(shapesState: ShapesState) extends Interpreter[RequestD
     val commands = Seq(
       AddShape(wrapperShapeId, OptionalKind.baseShapeId, ""),
       SetParameterShape(
-        ProviderInShape(wrapperShapeId, ShapeProvider(shapeDiff.expected.shapeId), "$optionalInner")
+        ProviderInShape(wrapperShapeId, ShapeProvider(shapeDiff.expected.shapeId), OptionalKind.innerParam)
       ),
       SetResponseBodyShape(requestDiffResult.responseId, ShapedBodyDescriptor(requestDiffResult.contentType, wrapperShapeId, isRemoved = false))
     )
diff --git a/domain/src/test/resources/diff-scenarios/todo-dry.events.json b/domain/src/test/resources/diff-scenarios/todo-dry.events.json
new file mode 100644
index 0000000000..d3502ef864
--- /dev/null
+++ b/domain/src/test/resources/diff-scenarios/todo-dry.events.json
@@ -0,0 +1,53 @@
+[
+  {"GitStateSet":{"branchName":"master","commitId":"843a3d0cf8d3db28303970fc9d031edef5e4c2d8","eventContext":{"clientCommandBatchId":"758951cf-6e5f-42c9-8975-5aafc9af3609","clientId":"acunniffe@gmail.com","clientSessionId":"3a9d1781-7e2a-430c-a2ad-e89b731b2987","createdAt":"2019-12-06T19:59:12.261Z"}}}
+,{"PathComponentAdded":{"eventContext":{"clientCommandBatchId":"6a48e6e3-e428-4d58-8aba-1bb1b27c9d7c","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:16.599Z"},"name":"todos","parentPathId":"root","pathId":"path_ubDE6MiMpT"}}
+,{"RequestAdded":{"eventContext":{"clientCommandBatchId":"82ab54ea-c3c8-4152-8033-2a343672b0a7","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:19.522Z"},"httpMethod":"GET","pathId":"path_ubDE6MiMpT","requestId":"request_CRRIXlDlNB"}}
+,{"ContributionAdded":{"eventContext":{"clientCommandBatchId":"82ab54ea-c3c8-4152-8033-2a343672b0a7","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:19.523Z"},"id":"request_CRRIXlDlNB","key":"purpose","value":"Get Todos"}}
+,{"ResponseAdded":{"eventContext":{"clientCommandBatchId":"fab68356-dbd7-4f4b-b86b-b9d18ef3e1c3","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:20.374Z"},"httpStatusCode":200,"requestId":"request_CRRIXlDlNB","responseId":"response_axt4cOEjVX"}}
+,{"ShapeAdded":{"baseShapeId":"$list","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.370Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_0"}}
+,{"ShapeAdded":{"baseShapeId":"$object","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.370Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.370Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_3"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.370Z"},"fieldId":"JDN4GJ_2","name":"dueDate","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"JDN4GJ_2","shapeId":"JDN4GJ_3"}},"shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.370Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_5"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"fieldId":"JDN4GJ_4","name":"id","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"JDN4GJ_4","shapeId":"JDN4GJ_5"}},"shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"$boolean","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_7"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"fieldId":"JDN4GJ_6","name":"isDone","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"JDN4GJ_6","shapeId":"JDN4GJ_7"}},"shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_9"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"fieldId":"JDN4GJ_8","name":"task","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"JDN4GJ_8","shapeId":"JDN4GJ_9"}},"shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"JDN4GJ_1","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"JDN4GJ_10"}}
+,{"ShapeParameterShapeSet":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.371Z"},"shapeDescriptor":{"ProviderInShape":{"consumingParameterId":"$listItem","providerDescriptor":{"ShapeProvider":{"shapeId":"JDN4GJ_10"}},"shapeId":"JDN4GJ_0"}}}}
+,{"ShapeAdded":{"baseShapeId":"JDN4GJ_0","eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.372Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_q0gY8gAvcX"}}
+,{"ResponseBodySet":{"bodyDescriptor":{"httpContentType":"application/json; charset=utf-8","isRemoved":false,"shapeId":"shape_q0gY8gAvcX"},"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.372Z"},"responseId":"response_axt4cOEjVX"}}
+,{"ShapeRenamed":{"eventContext":{"clientCommandBatchId":"5c1c454a-d520-4a1e-8df9-b239eb0c5dfd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:25.372Z"},"name":"ToDo","shapeId":"JDN4GJ_1"}}
+,{"ShapeAdded":{"baseShapeId":"$optional","eventContext":{"clientCommandBatchId":"b873edf8-05c2-485d-8538-bfe24c66d6f8","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:27.014Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_jan42wMGUH"}}
+,{"ShapeParameterShapeSet":{"eventContext":{"clientCommandBatchId":"b873edf8-05c2-485d-8538-bfe24c66d6f8","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:27.014Z"},"shapeDescriptor":{"ProviderInShape":{"consumingParameterId":"$optionalInner","providerDescriptor":{"ShapeProvider":{"shapeId":"JDN4GJ_3"}},"shapeId":"shape_jan42wMGUH"}}}}
+,{"FieldShapeSet":{"eventContext":{"clientCommandBatchId":"b873edf8-05c2-485d-8538-bfe24c66d6f8","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:27.014Z"},"shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"JDN4GJ_2","shapeId":"shape_jan42wMGUH"}}}}
+,{"ShapeRenamed":{"eventContext":{"clientCommandBatchId":"b873edf8-05c2-485d-8538-bfe24c66d6f8","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:27.014Z"},"name":"ToDo","shapeId":"JDN4GJ_1"}}
+,{"RequestAdded":{"eventContext":{"clientCommandBatchId":"9736a89c-2098-4714-8b0d-d8e79e91bc98","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:34.275Z"},"httpMethod":"POST","pathId":"path_ubDE6MiMpT","requestId":"request_6yVKPpNNau"}}
+,{"ContributionAdded":{"eventContext":{"clientCommandBatchId":"9736a89c-2098-4714-8b0d-d8e79e91bc98","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:34.275Z"},"id":"request_6yVKPpNNau","key":"purpose","value":"Post Todos"}}
+,{"ShapeAdded":{"baseShapeId":"$object","eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.048Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"oqPnII_0"}}
+,{"ShapeAdded":{"baseShapeId":"$boolean","eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"oqPnII_2"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"fieldId":"oqPnII_1","name":"isDone","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"oqPnII_1","shapeId":"oqPnII_2"}},"shapeId":"oqPnII_0"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"oqPnII_4"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"fieldId":"oqPnII_3","name":"task","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"oqPnII_3","shapeId":"oqPnII_4"}},"shapeId":"oqPnII_0"}}
+,{"ShapeAdded":{"baseShapeId":"oqPnII_0","eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_rSL5bkmj1f"}}
+,{"RequestBodySet":{"bodyDescriptor":{"httpContentType":"application/json","isRemoved":false,"shapeId":"shape_rSL5bkmj1f"},"eventContext":{"clientCommandBatchId":"e87170aa-600d-41e1-8f18-ddc1390784e4","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.049Z"},"requestId":"request_6yVKPpNNau"}}
+,{"ResponseAdded":{"eventContext":{"clientCommandBatchId":"8a590e69-52d1-4a3e-8acd-ec17fd144f23","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.235Z"},"httpStatusCode":200,"requestId":"request_6yVKPpNNau","responseId":"response_mH9VALt4C6"}}
+,{"ShapeAdded":{"baseShapeId":"JDN4GJ_1","eventContext":{"clientCommandBatchId":"0607584e-fcfc-42f4-9f91-eaabeeb161cc","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.404Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_40NUsNxVqW"}}
+,{"ResponseBodySet":{"bodyDescriptor":{"httpContentType":"application/json; charset=utf-8","isRemoved":false,"shapeId":"shape_40NUsNxVqW"},"eventContext":{"clientCommandBatchId":"0607584e-fcfc-42f4-9f91-eaabeeb161cc","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:35.405Z"},"responseId":"response_mH9VALt4C6"}}
+,{"PathParameterAdded":{"eventContext":null,"name":"todoId","parentPathId":"path_ubDE6MiMpT","pathId":"path_0muA2gwEhN"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":null,"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_O0VNCw0mwc"}}
+,{"PathParameterShapeSet":{"eventContext":null,"pathId":"path_0muA2gwEhN","shapeDescriptor":{"isRemoved":false,"shapeId":"shape_O0VNCw0mwc"}}}
+,{"RequestAdded":{"eventContext":{"clientCommandBatchId":"ecec8724-20a6-4cbe-80b0-be9a58fd75cd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.309Z"},"httpMethod":"PATCH","pathId":"path_0muA2gwEhN","requestId":"request_uKHqw2t5H7"}}
+,{"ContributionAdded":{"eventContext":{"clientCommandBatchId":"ecec8724-20a6-4cbe-80b0-be9a58fd75cd","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.310Z"},"id":"request_uKHqw2t5H7","key":"purpose","value":"Update todo by ID"}}
+,{"ShapeAdded":{"baseShapeId":"$object","eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.547Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"a9WGek_0"}}
+,{"ShapeAdded":{"baseShapeId":"$boolean","eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.547Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"a9WGek_2"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.547Z"},"fieldId":"a9WGek_1","name":"isDone","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"a9WGek_1","shapeId":"a9WGek_2"}},"shapeId":"a9WGek_0"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.547Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"a9WGek_4"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.547Z"},"fieldId":"a9WGek_3","name":"task","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"a9WGek_3","shapeId":"a9WGek_4"}},"shapeId":"a9WGek_0"}}
+,{"ShapeAdded":{"baseShapeId":"a9WGek_0","eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.548Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_omkKhi0yhQ"}}
+,{"RequestBodySet":{"bodyDescriptor":{"httpContentType":"application/json","isRemoved":false,"shapeId":"shape_omkKhi0yhQ"},"eventContext":{"clientCommandBatchId":"30908746-b440-4658-b18c-cd4c81740bd5","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:44.548Z"},"requestId":"request_uKHqw2t5H7"}}
+,{"ResponseAdded":{"eventContext":{"clientCommandBatchId":"2246291e-093d-45bb-a39c-590ad0019dc7","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:45.276Z"},"httpStatusCode":200,"requestId":"request_uKHqw2t5H7","responseId":"response_nd9psWnF0h"}}
+,{"ShapeAdded":{"baseShapeId":"JDN4GJ_1","eventContext":{"clientCommandBatchId":"f54aad2d-72a8-4e4d-9608-2c08ecb252ad","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:45.703Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_PGDymHodJu"}}
+,{"ResponseBodySet":{"bodyDescriptor":{"httpContentType":"application/json; charset=utf-8","isRemoved":false,"shapeId":"shape_PGDymHodJu"},"eventContext":{"clientCommandBatchId":"f54aad2d-72a8-4e4d-9608-2c08ecb252ad","clientId":"acunniffe@gmail.com","clientSessionId":"0897e549-8c0b-4f96-8bc6-148b01b730d0","createdAt":"2019-12-06T19:59:45.703Z"},"responseId":"response_nd9psWnF0h"}}
+]
diff --git a/domain/src/test/resources/diff-scenarios/todo.events.json b/domain/src/test/resources/diff-scenarios/todo.events.json
new file mode 100644
index 0000000000..6231df11cf
--- /dev/null
+++ b/domain/src/test/resources/diff-scenarios/todo.events.json
@@ -0,0 +1,70 @@
+[
+  {"APINamed":{"eventContext":null,"name":"ToDo"}}
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+,{"ShapeAdded":{"baseShapeId":"$object","eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.142Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"TtrW0r_0"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.142Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"TtrW0r_2"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.142Z"},"fieldId":"TtrW0r_1","name":"id","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"TtrW0r_1","shapeId":"TtrW0r_2"}},"shapeId":"TtrW0r_0"}}
+,{"ShapeAdded":{"baseShapeId":"$boolean","eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.142Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"TtrW0r_4"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.142Z"},"fieldId":"TtrW0r_3","name":"isDone","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"TtrW0r_3","shapeId":"TtrW0r_4"}},"shapeId":"TtrW0r_0"}}
+,{"ShapeAdded":{"baseShapeId":"$string","eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.143Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"TtrW0r_6"}}
+,{"FieldAdded":{"eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.143Z"},"fieldId":"TtrW0r_5","name":"task","shapeDescriptor":{"FieldShapeFromShape":{"fieldId":"TtrW0r_5","shapeId":"TtrW0r_6"}},"shapeId":"TtrW0r_0"}}
+,{"ShapeAdded":{"baseShapeId":"TtrW0r_0","eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.143Z"},"name":"","parameters":{"DynamicParameterList":{"shapeParameterIds":[]}},"shapeId":"shape_nipWvy4n2j"}}
+,{"ResponseBodySet":{"bodyDescriptor":{"httpContentType":"application/json; charset=utf-8","isRemoved":false,"shapeId":"shape_nipWvy4n2j"},"eventContext":{"clientCommandBatchId":"2eb865ad-b1c6-471a-8a1b-48b020124b3f","clientId":"acunniffe@gmail.com","clientSessionId":"661036ff-78db-407e-a94f-581f748f456b","createdAt":"2019-12-06T18:57:07.143Z"},"responseId":"response_Y6c4kqh5ru"}}
+]
diff --git a/domain/src/test/scala/com/seamless/contexts/rfc/OASProjectionSpec.scala b/domain/src/test/scala/com/seamless/contexts/rfc/OASProjectionSpec.scala
new file mode 100644
index 0000000000..72e919716b
--- /dev/null
+++ b/domain/src/test/scala/com/seamless/contexts/rfc/OASProjectionSpec.scala
@@ -0,0 +1,42 @@
+package com.seamless.contexts.rfc
+
+import com.seamless.contexts.rfc.projections.OASProjection
+import com.seamless.contexts.shapes.projections.{JsonSchemaProjection}
+import com.seamless.diff.JsonFileFixture
+import org.scalatest.FunSpec
+
+class OASProjectionSpec extends FunSpec with JsonFileFixture {
+  val commandContext: RfcCommandContext = RfcCommandContext("a", "b", "c")
+
+  def fixture(slug: String): (InMemoryQueries, RfcService, RfcState) = {
+
+    val eventStore = RfcServiceJSFacade.makeEventStore()
+    eventStore.append("id", eventsFrom(slug))
+    val rfcService: RfcService = new RfcService(eventStore)
+
+    (new InMemoryQueries(eventStore, rfcService, "id"), rfcService, rfcService.currentState("id"))
+  }
+
+  it("works for basic todo app") {
+    val (queries, rfcService, rfcState) = fixture("todo")
+    val oas = new OASProjection(queries, rfcService, "id")
+    assert(oas.generate.noSpaces == "{\"openapi\":\"3.0.1\",\"info\":{\"title\":\"ToDo\",\"version\":\"68\"},\"paths\":{\"/todos\":{\"get\":{\"operationId\":\"request_H4N9eE2ueT\",\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"type\":\"array\",\"items\":{\"type\":\"object\",\"required\":[\"id\",\"isDone\",\"task\"],\"properties\":{\"dueDate\":{\"type\":\"string\"},\"id\":{\"type\":\"string\"},\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}},\"description\":\"\"}}},\"post\":{\"operationId\":\"request_jSdvEiRo9a\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"type\":\"object\",\"required\":[\"isDone\",\"task\"],\"properties\":{\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}},\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"type\":\"object\",\"required\":[\"id\",\"isDone\",\"task\"],\"properties\":{\"id\":{\"type\":\"string\"},\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}},\"description\":\"\"}}},\"parameters\":[]},\"/todos/{todoId}\":{\"patch\":{\"operationId\":\"request_Pa77UBarCD\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"type\":\"object\",\"required\":[\"isDone\",\"task\"],\"properties\":{\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}},\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"type\":\"object\",\"required\":[\"dueDate\",\"id\",\"isDone\",\"task\"],\"properties\":{\"dueDate\":{\"type\":\"string\"},\"id\":{\"type\":\"string\"},\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}},\"description\":\"\"}}},\"parameters\":[{\"in\":\"path\",\"name\":\"todoId\",\"required\":true,\"schema\":{\"type\":\"string\"}}]}},\"components\":{\"schemas\":{}}}")
+  }
+
+  it("works for basic dry todo app") {
+    val (queries, rfcService, rfcState) = fixture("todo-dry")
+    val oas = new OASProjection(queries, rfcService, "id")
+    assert(oas.generate.noSpaces == "{\"openapi\":\"3.0.1\",\"info\":{\"title\":\"Unnamed API\",\"version\":\"51\"},\"paths\":{\"/todos\":{\"get\":{\"operationId\":\"request_CRRIXlDlNB\",\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"type\":\"array\",\"items\":{\"$ref\":\"#/components/schemas/ToDo\"}}}},\"description\":\"\"}}},\"post\":{\"operationId\":\"request_6yVKPpNNau\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"type\":\"object\",\"required\":[\"isDone\",\"task\"],\"properties\":{\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}},\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"$ref\":\"#/components/schemas/ToDo\"}}},\"description\":\"\"}}},\"parameters\":[]},\"/todos/{todoId}\":{\"patch\":{\"operationId\":\"request_uKHqw2t5H7\",\"requestBody\":{\"content\":{\"application/json\":{\"schema\":{\"type\":\"object\",\"required\":[\"isDone\",\"task\"],\"properties\":{\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}},\"responses\":{\"200\":{\"content\":{\"application/json; charset=utf-8\":{\"schema\":{\"$ref\":\"#/components/schemas/ToDo\"}}},\"description\":\"\"}}},\"parameters\":[{\"in\":\"path\",\"name\":\"todoId\",\"required\":true,\"schema\":{\"type\":\"string\"}}]}},\"components\":{\"schemas\":{\"ToDo\":{\"type\":\"object\",\"required\":[\"id\",\"isDone\",\"task\"],\"properties\":{\"dueDate\":{\"type\":\"string\"},\"id\":{\"type\":\"string\"},\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}}}}")
+  }
+
+  describe("Json Schema") {
+
+    it("works for todo shape") {
+      val (queries, rfcService, rfcState) = fixture("todo")
+      val todoSchema = new JsonSchemaProjection("jghsd0_1")(rfcState.shapesState).asJsonSchema(expand = false)
+      assert(todoSchema.noSpaces == "{\"type\":\"object\",\"required\":[\"id\",\"isDone\",\"task\"],\"properties\":{\"dueDate\":{\"type\":\"string\"},\"id\":{\"type\":\"string\"},\"isDone\":{\"type\":\"boolean\"},\"task\":{\"type\":\"string\"}}}")
+    }
+
+  }
+}
+
diff --git a/domain/src/test/scala/com/seamless/diff/JsonFileFixture.scala b/domain/src/test/scala/com/seamless/diff/JsonFileFixture.scala
index 77ed07cd18..c6831ef056 100644
--- a/domain/src/test/scala/com/seamless/diff/JsonFileFixture.scala
+++ b/domain/src/test/scala/com/seamless/diff/JsonFileFixture.scala
@@ -4,8 +4,8 @@ import io.circe.Json
 import io.circe.jawn.parseFile
 import java.io.File
 
-import com.seamless.contexts.rfc.Commands
-import com.seamless.serialization.CommandSerialization
+import com.seamless.contexts.rfc.{Commands, Events}
+import com.seamless.serialization.{CommandSerialization, EventSerialization}
 
 import scala.util.Try
 
@@ -19,4 +19,9 @@ trait JsonFileFixture {
     val json = parseFile(new File(filePath)).right.get
     CommandSerialization.fromJson(json).get
   }
-}
\ No newline at end of file
+  def eventsFrom(slug: String): Vector[Events.RfcEvent] = {
+    val filePath = "src/test/resources/diff-scenarios/" + slug + ".events.json"
+    val json = parseFile(new File(filePath)).right.get
+    EventSerialization.fromJson(json).get
+  }
+}
diff --git a/domain/src/test/scala/com/seamless/diff/ShapeDifferSpec.scala b/domain/src/test/scala/com/seamless/diff/ShapeDifferSpec.scala
index 156ab06e6d..77a47d5454 100644
--- a/domain/src/test/scala/com/seamless/diff/ShapeDifferSpec.scala
+++ b/domain/src/test/scala/com/seamless/diff/ShapeDifferSpec.scala
@@ -1,6 +1,7 @@
 package com.seamless.diff
 
 import com.seamless.contexts.shapes.Commands.{DynamicParameterList, NoParameterList, ProviderInShape, ShapeProvider}
+import com.seamless.contexts.shapes.ShapesHelper.OptionalKind
 import com.seamless.contexts.shapes.{ShapeEntity, ShapeValue, ShapesAggregate, ShapesState}
 import com.seamless.diff.ShapeDiffer.MultipleInterpretations
 import io.circe.Json
@@ -92,7 +93,7 @@ class ShapeDifferSpec extends FunSpec {
       val expected = ShapeEntity("$x", shape, isRemoved = false)
       implicit val shapesState: ShapesState = ShapesAggregate.initialState
         .withShape(expected.shapeId, shape.baseShapeId, shape.parameters, shape.name)
-        .withShapeParameterShape(ProviderInShape(expected.shapeId, ShapeProvider("$string"), "$optionalInner"))
+        .withShapeParameterShape(ProviderInShape(expected.shapeId, ShapeProvider("$string"), OptionalKind.innerParam))
 
       describe("when given a string") {
         it("should return an empty diff") {