diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index e7aca4e..512ea4b 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -30,8 +30,11 @@ jobs:
         GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
       run: echo "GPG key loaded"
 
-    - name: Build and publish
-      run: ./gradlew build :preflight-core:preflight-gradle-plugin:publishPlugins :preflight-core:preflight-runtime:publishMavenPublicationToOrbitalRepository :preflight-core:preflight-spec:publishMavenPublicationToOrbitalRepository
+    - name: Publish preflight-spec
+      run: cd preflight-spec && ./gradlew build publishMavenPublicationToOrbitalRepository
+
+    - name: Build and publish preflight-core
+      run: ./gradlew build :preflight-core:preflight-gradle-plugin:publishPlugins :preflight-core:preflight-runtime:publishMavenPublicationToOrbitalRepository
       env:
         GRADLE_PUBLISH_KEY: ${{ secrets.GRADLE_PUBLISH_KEY }}
         GRADLE_PUBLISH_SECRET: ${{ secrets.GRADLE_PUBLISH_SECRET }}
diff --git a/BUILDING.md b/BUILDING.md
index 231c656..740fd05 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -1,19 +1,25 @@
 # Building and Releasing
 
-## Building locally
+## Project Structure
 
-```bash
-cd preflight-core
-./gradlew build
-```
+The repository uses two separate Gradle builds connected via composite builds:
+
+- **`preflight-spec/`** — Standalone build for the markdown test spec parser/writer. Has no Orbital dependencies (only commonmark + jackson), so Orbital itself can depend on it without circular dependencies.
+- **`preflight-core/`** — Main build containing `preflight-runtime` and `preflight-gradle-plugin`. Depends on Orbital libraries. Consumes `preflight-spec` via composite build (`includeBuild`).
 
-This builds all modules (`preflight-spec`, `preflight-runtime`, `preflight-gradle-plugin`) and runs their tests.
+The root `settings.gradle.kts` wires both builds together along with the example projects.
 
-To also run the example project tests:
+## Building locally
 
 ```bash
-# From the repo root
+# Full build from repo root (builds everything including examples)
 ./gradlew build
+
+# Build preflight-spec standalone
+cd preflight-spec && ./gradlew build
+
+# Build preflight-core (resolves preflight-spec via composite build)
+cd preflight-core && ./gradlew build
 ```
 
 ## Installing to local Maven repo
@@ -51,16 +57,12 @@ The plugin itself injects the Orbital Maven repositories automatically, so no ot
 
 ## Bumping the version
 
-The version is set in one place: `preflight-core/build.gradle.kts`
+The version is set in **two places** (kept in sync manually):
 
-```kotlin
-allprojects {
-    group = "com.orbitalhq.preflight"
-    version = "0.1.0"  // <-- change this
-}
-```
+1. `preflight-core/build.gradle.kts` — `val PROJECT_VERSION = "0.1.0-SNAPSHOT"`
+2. `preflight-spec/build.gradle.kts` — `version = "0.1.0-SNAPSHOT"`
 
-All submodules inherit this version. The Gradle plugin also embeds it at build time via a generated `Versions.kt` constant.
+All preflight-core submodules inherit their version from `preflight-core/build.gradle.kts`. The Gradle plugin also embeds it at build time via a generated `Versions.kt` constant.
 
 ## Releasing
 
@@ -71,7 +73,7 @@ Releases are triggered by pushing a git tag. GitHub Actions handles building, si
 git checkout main
 git pull
 
-# 2. Bump the version in preflight-core/build.gradle.kts, commit
+# 2. Bump the version in both build.gradle.kts files, commit
 
 # 3. Tag the release
 git tag v0.1.0
@@ -84,9 +86,10 @@ git push origin v0.1.0
 The `release.yml` workflow then:
 1. Builds the project with JDK 21
 2. Signs artifacts with GPG
-3. Publishes the Gradle plugin to the **Gradle Plugin Portal**
-4. Publishes `preflight-runtime` and `preflight-spec` to the **Orbital Maven repository** (`s3://repo.orbitalhq.com/release`)
-5. Creates a GitHub Release with JARs and auto-generated notes
+3. Publishes `preflight-spec` to the **Orbital Maven repository**
+4. Publishes the Gradle plugin to the **Gradle Plugin Portal**
+5. Publishes `preflight-runtime` to the **Orbital Maven repository**
+6. Creates a GitHub Release with JARs and auto-generated notes
 
 ## Where artifacts are published
 
diff --git a/CLAUDE.md b/CLAUDE.md
index 83339bd..b884fba 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,11 +8,17 @@ Preflight is a Kotlin-based testing framework for Taxi/Orbital projects. It prov
 
 ### Core Components
 
+- **preflight-spec**: Standalone markdown test spec parser/writer (`preflight-spec/`)
+  - Has zero Orbital dependencies (only commonmark + jackson)
+  - Lives in its own top-level Gradle build so Orbital can depend on it without circular dependencies
+  - `TestSpecReader` / `TestSpecWriter`: Parse and generate markdown test specifications
+
 - **preflight-runtime**: Core testing DSL and execution engine (`preflight-core/preflight-runtime/`)
   - `OrbitalSpec`: Base test class extending Kotest's DescribeSpec with Taxi/Orbital-specific functionality
   - `PreflightExtension`: Kotest extension that handles Taxi compilation and Orbital service initialization
   - `StubHelper`: Utilities for stubbing external data sources in tests
   - Environment variable support and configuration management
+  - Depends on `preflight-spec` via Maven coordinates (resolved by composite build locally)
 
 - **preflight-gradle-plugin**: Gradle plugin for project integration (`preflight-core/preflight-gradle-plugin/`)
   - `PreflightPlugin`: Main plugin class that configures Kotlin JVM, dependencies, and test execution
@@ -20,8 +26,10 @@ Preflight is a Kotlin-based testing framework for Taxi/Orbital projects. It prov
 
 ### Project Structure
 
-The repository uses a composite build structure:
-- Root project includes core modules and example projects as composite builds
+The repository uses a two-build composite structure:
+- `preflight-spec/` — standalone Gradle build (no Orbital dependencies)
+- `preflight-core/` — main Gradle build containing runtime and plugin (depends on Orbital)
+- Root `settings.gradle.kts` wires both builds together with example projects via `includeBuild`
 - Example projects demonstrate usage patterns and serve as integration tests
 - Documentation site built with Next.js in `docs/` directory
 
@@ -119,4 +127,8 @@ preflight {
 
 ## Version Management
 
-Project version is managed centrally in `preflight-core/build.gradle.kts` (currently 0.0.4). The Gradle plugin uses code generation to embed version constants at build time via the `generateVersionConstants` task.
\ No newline at end of file
+Project version is set in two places (kept in sync manually):
+- `preflight-core/build.gradle.kts` — `val PROJECT_VERSION = "0.1.0-SNAPSHOT"` (inherited by runtime and plugin)
+- `preflight-spec/build.gradle.kts` — `version = "0.1.0-SNAPSHOT"`
+
+The Gradle plugin uses code generation to embed version constants at build time via the `generateVersionConstants` task.
\ No newline at end of file
diff --git a/example-projects/warehouse-orders/build.gradle.kts b/example-projects/warehouse-orders/build.gradle.kts
index 2e5e3d5..dd1d35c 100644
--- a/example-projects/warehouse-orders/build.gradle.kts
+++ b/example-projects/warehouse-orders/build.gradle.kts
@@ -7,24 +7,24 @@ plugins {
 
 // OR specify a custom Orbital version
 preflight {
-   orbitalVersion = "0.38.0-SNAPSHOT"
+   orbitalVersion = "0.38.0-M4"
 }
 
 repositories {
    mavenLocal()
    mavenCentral()
-   maven {
-      name = "orbital"
-      url = URI("https://repo.orbitalhq.com/release")
-      mavenContent {
-         releasesOnly()
-      }
-   }
-   maven {
-      name = "orbital-snapshot"
-      url = URI("https://repo.orbitalhq.com/snapshot")
-      mavenContent {
-         snapshotsOnly()
-      }
-   }
+//   maven {
+//      name = "orbital"
+//      url = URI("https://repo.orbitalhq.com/release")
+//      mavenContent {
+//         releasesOnly()
+//      }
+//   }
+//   maven {
+//      name = "orbital-snapshot"
+//      url = URI("https://repo.orbitalhq.com/snapshot")
+//      mavenContent {
+//         snapshotsOnly()
+//      }
+//   }
 }
diff --git a/example-projects/warehouse-orders/test-resources/specs/enrich-warehouse-order.spec.md b/example-projects/warehouse-orders/test-resources/specs/enrich-warehouse-order.spec.md
index 8b410a4..a3e9166 100644
--- a/example-projects/warehouse-orders/test-resources/specs/enrich-warehouse-order.spec.md
+++ b/example-projects/warehouse-orders/test-resources/specs/enrich-warehouse-order.spec.md
@@ -4,7 +4,7 @@ spec-version: 0.1
 
 # Enrich warehouse order
 
-This test covers streaming a warehouse order event and eniching it with a product name from an API
+This test covers streaming a warehouse order event and enriching it with a product name from an API
 
 ## Query
 
@@ -24,31 +24,75 @@ stream { SurePostDeliveryEvent } as {
 Message:
 ```json
 {
-  "productId" : "PROD-1001",
-  "qtyDelivered" : 45,
-  "orderId" : "520c80f8-661e-48c7-8b4e-c9c36bd93785",
+  "productId" : "PROD-1013",
+  "qtyDelivered" : 72,
+  "orderId" : "a29788b5-6b7a-4c30-8e9c-775c1341fef8",
   "supplierId" : "SUREPOST",
-  "timestamp" : "2026-02-26T05:54:25.719167197"
+  "timestamp" : "2026-02-27T08:21:37.136364734"
 }
 ```
 
+Message:
+```json
+{
+  "productId" : "PROD-1003",
+  "qtyDelivered" : 20,
+  "orderId" : "e69e51a4-85e6-4fe6-90a8-4faec726e316",
+  "supplierId" : "SUREPOST",
+  "timestamp" : "2026-02-27T08:21:39.136643659"
+}
+```
+
+Message:
+```json
+{
+  "productId" : "PROD-1003",
+  "qtyDelivered" : 26,
+  "orderId" : "5e3ea02a-9eaf-45c9-ab66-9150d5aeb981",
+  "supplierId" : "SUREPOST",
+  "timestamp" : "2026-02-27T08:21:41.136906122"
+}
+```
+
+### getProduct
+<!-- operation: ProductsApi@@getProduct -->
+
+Request:
+```json
+{
+  "productId" : "PROD-1013"
+}
+```
+
+Response:
+```json
+{"productId":"PROD-1013","sku":"SKU-WEB013","productName":"HD Webcam with Microphone","category":"Electronics","storageLocation":"WAREHOUSE-A-02"}
+```
+
 ### getProduct
 <!-- operation: ProductsApi@@getProduct -->
 
+Request:
+```json
+{
+  "productId" : "PROD-1003"
+}
+```
+
 Response:
 ```json
-{"productId":"PROD-1001","sku":"SKU-LAP001","productName":"Gaming Laptop Pro 15\"","category":"Electronics","storageLocation":"WAREHOUSE-A-02"}
+{"productId":"PROD-1003","sku":"SKU-KEY003","productName":"Mechanical Keyboard RGB","category":"Accessories","storageLocation":"WAREHOUSE-B-01"}
 ```
 
 ## Expected Result
 
 ```json
 {
-  "productName" : "Gaming Laptop Pro 15\"",
-  "productId" : "PROD-1001",
-  "qtyDelivered" : 45,
-  "orderId" : "520c80f8-661e-48c7-8b4e-c9c36bd93785",
+  "productName" : "HD Webcam with Microphone",
+  "productId" : "PROD-1013",
+  "qtyDelivered" : 72,
+  "orderId" : "a29788b5-6b7a-4c30-8e9c-775c1341fef8",
   "supplierId" : "SUREPOST",
-  "timestamp" : "26-Feb-2026 05:54:25"
+  "timestamp" : "27-Feb-2026 08:21:37"
 }
-```
+```
\ No newline at end of file
diff --git a/preflight-core/build.gradle.kts b/preflight-core/build.gradle.kts
index 81fd26f..d9a9610 100644
--- a/preflight-core/build.gradle.kts
+++ b/preflight-core/build.gradle.kts
@@ -9,6 +9,7 @@ plugins {
     `maven-publish`
 }
 
+val PROJECT_VERSION = "0.1.0-SNAPSHOT"
 
 
 tasks.register("publishAll") {
@@ -26,7 +27,7 @@ tasks.register("publishAllMavenLocal") {
 
 allprojects {
     group = "com.orbitalhq.preflight"
-    version = "0.1.0-M2"
+    version = PROJECT_VERSION
 
     repositories {
         mavenCentral()
diff --git a/preflight-core/preflight-gradle-plugin/build.gradle.kts b/preflight-core/preflight-gradle-plugin/build.gradle.kts
index f810748..9043627 100644
--- a/preflight-core/preflight-gradle-plugin/build.gradle.kts
+++ b/preflight-core/preflight-gradle-plugin/build.gradle.kts
@@ -52,6 +52,7 @@ tasks.shadowJar {
     archiveClassifier.set("")  // Make this the main JAR
     dependencies {
         include(project(":preflight-runtime"))
+        include(dependency("com.orbitalhq.preflight:preflight-spec"))
         include(dependency("org.taxilang:.*"))
         include(dependency("com.orbitalhq:.*"))
     }
diff --git a/preflight-core/preflight-runtime/build.gradle.kts b/preflight-core/preflight-runtime/build.gradle.kts
index d76289c..c161530 100644
--- a/preflight-core/preflight-runtime/build.gradle.kts
+++ b/preflight-core/preflight-runtime/build.gradle.kts
@@ -4,10 +4,10 @@ plugins {
 }
 
 val taxiVersion = "1.71.0-SNAPSHOT"
-val orbitalVersion = "0.38.0-SNAPSHOT" // Default version, can be overridden in consumer projects
+val orbitalVersion = "0.38.0-M4" // Default version, can be overridden in consumer projects
 
 dependencies {
-    implementation(project(":preflight-spec"))
+    implementation("com.orbitalhq.preflight:preflight-spec")
     testImplementation(platform("org.junit:junit-bom:5.10.0"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     implementation(platform("org.testcontainers:testcontainers-bom:1.19.3"))
diff --git a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/MarkdownSpec.kt b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/MarkdownSpec.kt
index b9e47fe..b04a62f 100644
--- a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/MarkdownSpec.kt
+++ b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/MarkdownSpec.kt
@@ -1,18 +1,19 @@
 package com.orbitalhq.preflight.dsl
 
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import com.orbitalhq.models.Provided
-import com.orbitalhq.models.TypedInstance
-import com.orbitalhq.models.json.right
+import com.fasterxml.jackson.module.kotlin.readValue
+import com.orbitalhq.models.json.Jackson
+import com.orbitalhq.preflight.spec.Stub
 import com.orbitalhq.preflight.spec.StubMode
 import com.orbitalhq.preflight.spec.TestSpec
 import com.orbitalhq.preflight.spec.TestSpecReader
-import com.orbitalhq.schemas.fqn
+import com.orbitalhq.query.RemoteCallExchangeMetadata
 import com.orbitalhq.stubbing.StubService
 import io.kotest.matchers.shouldBe
 import kotlinx.coroutines.flow.flowOf
 import java.nio.file.Files
-import java.nio.file.Path
 import java.nio.file.Paths
 import kotlin.io.path.extension
 import kotlin.io.path.isRegularFile
@@ -41,24 +42,65 @@ abstract class MarkdownSpec(
 
 private fun OrbitalSpec.registerSpec(
     spec: TestSpec,
-    objectMapper: com.fasterxml.jackson.databind.ObjectMapper
+    objectMapper: ObjectMapper
 ) {
     val stubCustomizer: (StubService) -> Unit = { stubService ->
-        for (stub in spec.dataSources) {
-            when (stub.mode) {
-                StubMode.REQUEST_RESPONSE -> {
-                    val response = stub.response
-                    if (response != null) {
-                        stubService.addResponse(stub.operationName, response)
+
+        val stubsByOperationName = spec.dataSources.groupBy { it.operationName }
+        stubsByOperationName
+            .forEach { (operationName, stubbedCalls) ->
+                if (stubbedCalls.isNotEmpty()) {
+                    val modes = stubbedCalls.map { it.mode }.distinct()
+                    if (modes.size > 1) {
+                        // There's no reason we can't support this in theory, but I don't think it's a real use-case,
+                        // and complicates the execution, as we need to further split these
+                        error("Operation $operationName has a mix of stub modes (${modes.joinToString()}) which is not currently supported")
                     }
-                }
-                StubMode.STREAM -> {
-                    stubService.addResponseFlow(stub.operationName) { _,_ ->
-                        val messages = messagesAsTypedInstanceResponses(stub, stubService.schema!!)
-                        flowOf(*messages.toTypedArray())
+                    val singleStubMode = modes.single()
+                    when (singleStubMode) {
+                        StubMode.STREAM -> {
+                            stubbedCalls.forEach { stub ->
+                                stubService.addResponseFlow(stub.operationName) { _,_ ->
+                                    val messages = stubResponseAsTypedInstanceResponses(stub, stubService.schema!!)
+                                    flowOf(*messages.toTypedArray())
+                                }
+                            }
+                        }
+
+                        StubMode.REQUEST_RESPONSE -> {
+                            val stubbedCallsByParameters: List<Pair<Map<String, Any?>, Stub>> = stubbedCalls.map { stubbedCall ->
+                                val parametersAsMap = if (stubbedCall.parameters != null) {
+                                    Jackson.defaultObjectMapper.readValue<Map<String,Any?>>(stubbedCall.parameters!!)
+                                } else emptyMap()
+                                parametersAsMap to stubbedCall
+                            }
+                            stubService.addResponse(operationName) { _,parameters ->
+                                // We need to match the request with the incoming parameters
+                                if (parameters.isEmpty()) {
+                                    // If there's no parameters provided, we just match the first call
+                                    if (stubbedCalls.size != 1) {
+                                        error("The test spec is ambiguous. There are ${stubbedCalls.size} calls configured for ${operationName}, but no parameters are declared on the operation, so cannot determine which to pick")
+                                    } else {
+                                        val stubbedCall = stubbedCalls.single()
+                                        stubResponseAsTypedInstanceResponses(stubbedCall, stubService.schema!!)
+                                    }
+                                } else {
+                                    // Otherwise, we need to map on parameters
+                                    val receivedParametersAsMap = RemoteCallExchangeMetadata.convertParametersToMap(parameters)
+                                    val matchingCalls = stubbedCallsByParameters.filter { it.first == receivedParametersAsMap }
+                                    when (matchingCalls.size) {
+                                        0 -> error("No stubbed operation calls for operation ${operationName} matched on the provided parameters, although ${stubbedCalls.size} stubs are configured for this operation. Provided parameters: ${receivedParametersAsMap}")
+                                        1 -> stubResponseAsTypedInstanceResponses(matchingCalls.single().second, stubService.schema!!)
+                                        else -> error("The test spec is ambiguous. There are ${matchingCalls.size} calls configured for ${operationName}, which match the parameters provided: ${receivedParametersAsMap}")
+                                    }
+
+                                }
+                            }
+                        }
                     }
                 }
-            }
+
+
         }
     }
 
@@ -69,11 +111,11 @@ private fun OrbitalSpec.registerSpec(
 
             if (isArray) {
                 val actual = spec.query.queryForCollectionOfMaps(stubCustomizer)
-                val actualJson = objectMapper.valueToTree<com.fasterxml.jackson.databind.JsonNode>(actual)
+                val actualJson = objectMapper.valueToTree<JsonNode>(actual)
                 actualJson shouldBe expectedJson
             } else {
                 val actual = spec.query.queryForMap(stubCustomizer)
-                val actualJson = objectMapper.valueToTree<com.fasterxml.jackson.databind.JsonNode>(actual)
+                val actualJson = objectMapper.valueToTree<JsonNode>(actual)
                 actualJson shouldBe expectedJson
             }
         }
diff --git a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/PreflightExtension.kt b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/PreflightExtension.kt
index dd028cd..88d908b 100644
--- a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/PreflightExtension.kt
+++ b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/PreflightExtension.kt
@@ -327,39 +327,40 @@ class PreflightExtension(
         val context = PreflightTestCaseContext(testCase)
         return withContext(context) {
             val testResult = execute(testCase)
-            val capturedScenario = capturedScenarios[testCase]
-            if (testResult.isFailure && capturedScenario != null) {
-                val failure = testResult as TestResult.Failure
-                val cause = failure.cause
-                if (cause is AssertionFailedError) {
-                    val originalError = failure.cause as AssertionFailedError
-                    val (_, playgroundLink) = PlaygroundScenarioFactory.buildPlaygroundScenario(
-                        capturedScenario,
-                        sourcePackage,
-                        schema,
-                        originalError,
-                        testCase
-                    )
-                    val errorMessageWithPlaygroundLink = """${originalError.message}
-                        |
-                        |This error is explorable in Taxi Playground at the following link: $playgroundLink
-                    """.trimMargin()
-                    val failureWithPlaygroundLink = failure.copy(
-                        cause = AssertionFailedError(
-                            message = errorMessageWithPlaygroundLink,
-                            cause = originalError.cause,
-                            expectedValue = originalError.expectedValue,
-                            actualValue = originalError.actualValue,
-                        )
-                    )
-                    failureWithPlaygroundLink
-                } else {
-                    testResult
-                }
-
-            } else {
-                testResult
-            }
+            testResult
+//            val capturedScenario = capturedScenarios[testCase]
+//            if (testResult.isFailure && capturedScenario != null) {
+//                val failure = testResult as TestResult.Failure
+//                val cause = failure.cause
+//                if (cause is AssertionFailedError) {
+//                    val originalError = failure.cause as AssertionFailedError
+////                    val (_, playgroundLink) = PlaygroundScenarioFactory.buildPlaygroundScenario(
+////                        capturedScenario,
+////                        sourcePackage,
+////                        schema,
+////                        originalError,
+////                        testCase
+////                    )
+////                    val errorMessageWithPlaygroundLink = """${originalError.message}
+////                        |
+////                        |This error is explorable in Taxi Playground at the following link: $playgroundLink
+////                    """.trimMargin()
+//                    val failureWithPlaygroundLink = failure.copy(
+//                        cause = AssertionFailedError(
+//                            message = originalError.message,
+//                            cause = originalError.cause,
+//                            expectedValue = originalError.expectedValue,
+//                            actualValue = originalError.actualValue,
+//                        )
+//                    )
+//                    failureWithPlaygroundLink
+//                } else {
+//                    testResult
+//                }
+//
+//            } else {
+//                testResult
+//            }
 
         }
     }
diff --git a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/StubHelper.kt b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/StubHelper.kt
index ed2edb5..c9d11c3 100644
--- a/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/StubHelper.kt
+++ b/preflight-core/preflight-runtime/src/main/kotlin/com/orbitalhq/preflight/dsl/StubHelper.kt
@@ -3,11 +3,13 @@ package com.orbitalhq.preflight.dsl
 import arrow.core.Either
 import com.orbitalhq.models.Provided
 import com.orbitalhq.models.TypedInstance
+import com.orbitalhq.models.TypedNull
 import com.orbitalhq.models.json.right
 import com.orbitalhq.preflight.spec.Stub
 import com.orbitalhq.query.StreamErrorMessage
 import com.orbitalhq.schemas.Schema
 import com.orbitalhq.schemas.fqn
+import lang.taxi.types.PrimitiveType
 import kotlin.collections.map
 import kotlin.collections.orEmpty
 
@@ -33,12 +35,34 @@ data class StubResponseBuilder(val operationName: String) {
 
 data class StubScenario(val operationName: String, val response: String)
 
-fun messagesAsTypedInstanceResponses(stub: Stub, schema: Schema): List<Either<StreamErrorMessage, TypedInstance>> {
-    val (_,operation) = schema.remoteOperation(stub.operationName.fqn())
-    val streamType = operation.returnType.typeParameters[0]
-    val messagesAsTypedInstances = stub.messages.orEmpty().map { json ->
-        TypedInstance.from(streamType, json, source = Provided, schema = schema)
-            .right()
+/**
+ * Converts the stub response (either a request response, or a stream) into
+ * the format expected by the stub service
+ */
+fun stubResponseAsTypedInstanceResponses(stub: Stub, schema: Schema): List<Either<StreamErrorMessage, TypedInstance>> {
+    val (_, operation) = schema.remoteOperation(stub.operationName.fqn())
+    // Unwrap Array or Stream types
+    val stubResponseAsTypedInstance = when {
+        stub.messages != null -> {
+            // Should be a stream
+            val responseType = operation.returnType.typeParameters[0]
+            stub.messages.orEmpty().map { json ->
+                TypedInstance.from(responseType, json, source = Provided, schema = schema)
+                    .right()
+            }
+        }
+        stub.response != null -> {
+            val responseType = operation.returnType
+            listOf(TypedInstance.from(responseType, stub.response, source = Provided, schema = schema).right())
+        }
+        else -> {
+            // No response provided -- could be a void method - so return null
+            // Not actually sure what to return here, since void methods don't typically exist,
+            // but doesn't feel like a reasonable reason to bail
+            listOf(TypedNull.create(schema.type(PrimitiveType.ANY)).right())
+        }
     }
-    return messagesAsTypedInstances
+    return stubResponseAsTypedInstance
+
+    return stubResponseAsTypedInstance
 }
\ No newline at end of file
diff --git a/preflight-core/settings.gradle.kts b/preflight-core/settings.gradle.kts
index b8e3711..470aefe 100644
--- a/preflight-core/settings.gradle.kts
+++ b/preflight-core/settings.gradle.kts
@@ -1,5 +1,6 @@
 rootProject.name = "preflight-core"
 
 include("preflight-runtime")
-include("preflight-spec")
 include("preflight-gradle-plugin")
+
+includeBuild("../preflight-spec")
diff --git a/preflight-core/preflight-spec/README.md b/preflight-spec/README.md
similarity index 100%
rename from preflight-core/preflight-spec/README.md
rename to preflight-spec/README.md
diff --git a/preflight-core/preflight-spec/build.gradle.kts b/preflight-spec/build.gradle.kts
similarity index 69%
rename from preflight-core/preflight-spec/build.gradle.kts
rename to preflight-spec/build.gradle.kts
index f4feac4..b89b9e5 100644
--- a/preflight-core/preflight-spec/build.gradle.kts
+++ b/preflight-spec/build.gradle.kts
@@ -1,9 +1,22 @@
 plugins {
-    kotlin("jvm")
+    kotlin("jvm") version "2.1.10"
     `maven-publish`
 }
 
+group = "com.orbitalhq.preflight"
+version = "0.1.0-SNAPSHOT"
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+}
+
+kotlin {
+    jvmToolchain(21)
+}
+
 dependencies {
+    implementation(kotlin("stdlib"))
     implementation("org.commonmark:commonmark:0.24.0")
     implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.17.2")
 
@@ -21,6 +34,14 @@ publishing {
     publications {
         create<MavenPublication>("maven") {
             from(components["java"])
+            pom {
+                licenses {
+                    license {
+                        name.set("The Apache License, Version 2.0")
+                        url.set("https://www.apache.org/licenses/LICENSE-2.0.txt")
+                    }
+                }
+            }
         }
     }
     repositories {
diff --git a/preflight-spec/gradle/wrapper/gradle-wrapper.jar b/preflight-spec/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..9bbc975
Binary files /dev/null and b/preflight-spec/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/preflight-spec/gradle/wrapper/gradle-wrapper.properties b/preflight-spec/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..37f78a6
--- /dev/null
+++ b/preflight-spec/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/preflight-spec/gradlew b/preflight-spec/gradlew
new file mode 100755
index 0000000..faf9300
--- /dev/null
+++ b/preflight-spec/gradlew
@@ -0,0 +1,251 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/preflight-spec/gradlew.bat b/preflight-spec/gradlew.bat
new file mode 100644
index 0000000..9d21a21
--- /dev/null
+++ b/preflight-spec/gradlew.bat
@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/preflight-spec/settings.gradle.kts b/preflight-spec/settings.gradle.kts
new file mode 100644
index 0000000..5a40745
--- /dev/null
+++ b/preflight-spec/settings.gradle.kts
@@ -0,0 +1 @@
+rootProject.name = "preflight-spec"
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/SpecParseException.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/SpecParseException.kt
similarity index 100%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/SpecParseException.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/SpecParseException.kt
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt
similarity index 95%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt
index 3e4f1f0..8a06303 100644
--- a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt
+++ b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpec.kt
@@ -20,6 +20,7 @@ data class Stub(
     val label: String,
     val operationName: String,
     val mode: StubMode,
+    val parameters: String?,
     val response: String?,
     val messages: List<String>?
 )
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt
similarity index 97%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt
index 1740b88..bcddba5 100644
--- a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt
+++ b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecReader.kt
@@ -44,6 +44,7 @@ object TestSpecReader {
         // Stub parsing state
         var currentStubLabel: String? = null
         var currentStubDirectives = mutableListOf<String>()
+        var currentStubParameters: String? = null
         var currentStubResponse: String? = null
         var currentStubMessages = mutableListOf<String>()
         var lastParagraphLabel: String? = null
@@ -88,12 +89,14 @@ object TestSpecReader {
                     operationName = operationName,
                     mode = mode,
                     response = if (mode == StubMode.REQUEST_RESPONSE) currentStubResponse else null,
-                    messages = if (mode == StubMode.STREAM) currentStubMessages.toList() else null
+                    messages = if (mode == StubMode.STREAM) currentStubMessages.toList() else null,
+                    parameters = currentStubParameters
                 )
             )
 
             currentStubLabel = null
             currentStubDirectives = mutableListOf()
+            currentStubParameters = null
             currentStubResponse = null
             currentStubMessages = mutableListOf()
             lastParagraphLabel = null
@@ -157,6 +160,7 @@ object TestSpecReader {
                             if (currentStubLabel != null) {
                                 val content = node.literal.trimEnd()
                                 when (lastParagraphLabel) {
+                                    "Request" -> currentStubParameters = content
                                     "Response" -> currentStubResponse = content
                                     "Message" -> currentStubMessages.add(content)
                                 }
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt
similarity index 92%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt
index 3eca62f..dce9c2b 100644
--- a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt
+++ b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/TestSpecWriter.kt
@@ -44,6 +44,14 @@ object TestSpecWriter {
             }
             appendLine()
 
+            if (stub.parameters != null) {
+                appendLine("Request:")
+                appendLine("```json")
+                appendLine(stub.parameters)
+                appendLine("```")
+                appendLine()
+            }
+
             when (stub.mode) {
                 StubMode.REQUEST_RESPONSE -> {
                     if (stub.response != null) {
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/DirectiveParser.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/DirectiveParser.kt
similarity index 100%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/DirectiveParser.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/DirectiveParser.kt
diff --git a/preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/FrontMatterParser.kt b/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/FrontMatterParser.kt
similarity index 100%
rename from preflight-core/preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/FrontMatterParser.kt
rename to preflight-spec/src/main/kotlin/com/orbitalhq/preflight/spec/internal/FrontMatterParser.kt
diff --git a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/DirectiveParserTest.kt b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/DirectiveParserTest.kt
similarity index 100%
rename from preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/DirectiveParserTest.kt
rename to preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/DirectiveParserTest.kt
diff --git a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt
similarity index 73%
rename from preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt
rename to preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt
index f57bdc5..63acc77 100644
--- a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt
+++ b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/RoundTripTest.kt
@@ -14,7 +14,7 @@ class RoundTripTest : DescribeSpec({
                 description = null,
                 query = "find { Customer }",
                 dataSources = listOf(
-                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null)
+                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null)
                 ),
                 expectedResult = """{ "id": "1" }""",
                 flow = null
@@ -30,8 +30,8 @@ class RoundTripTest : DescribeSpec({
                 description = "Tests with multiple data sources.",
                 query = "find { Customer } with { orders: Order[] }",
                 dataSources = listOf(
-                    Stub("Fetch Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "12345", "name": "Alice" }""", null),
-                    Stub("Fetch Orders", "getOrders", StubMode.REQUEST_RESPONSE, """[{ "orderId": "ORD-1" }]""", null)
+                    Stub("Fetch Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "12345", "name": "Alice" }""", messages = null),
+                    Stub("Fetch Orders", "getOrders", StubMode.REQUEST_RESPONSE, parameters = null, response = """[{ "orderId": "ORD-1" }]""", messages = null)
                 ),
                 expectedResult = """{ "customer": "Alice", "orders": [{ "orderId": "ORD-1" }] }""",
                 flow = null
@@ -48,8 +48,8 @@ class RoundTripTest : DescribeSpec({
                 query = "stream { Prices }",
                 dataSources = listOf(
                     Stub(
-                        "Price Updates", "priceStream", StubMode.STREAM, null,
-                        listOf("""{ "price": 100 }""", """{ "price": 200 }""", """{ "price": 300 }""")
+                        "Price Updates", "priceStream", StubMode.STREAM, parameters = null, response = null,
+                        messages = listOf("""{ "price": 100 }""", """{ "price": 200 }""", """{ "price": 300 }""")
                     )
                 ),
                 expectedResult = """[{ "price": 100 }, { "price": 200 }, { "price": 300 }]""",
@@ -66,7 +66,7 @@ class RoundTripTest : DescribeSpec({
                 description = "A comprehensive test case.",
                 query = "find { Customer }",
                 dataSources = listOf(
-                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null)
+                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null)
                 ),
                 expectedResult = """{ "id": "1" }""",
                 flow = "sequenceDiagram\n    Q->>S: getCustomer\n    S-->>Q: Customer"
@@ -82,7 +82,7 @@ class RoundTripTest : DescribeSpec({
                 description = null,
                 query = "find { Customer }",
                 dataSources = listOf(
-                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null)
+                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null)
                 ),
                 expectedResult = """{ "type": "Customer", "value": { "id": "1" } }""",
                 resultFormat = ResultFormat.TYPED_INSTANCE,
@@ -99,7 +99,7 @@ class RoundTripTest : DescribeSpec({
                 description = null,
                 query = "find { Customer }",
                 dataSources = listOf(
-                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null)
+                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null)
                 ),
                 expectedResult = """{ "id": "1" }""",
                 resultFormat = ResultFormat.JSON,
@@ -116,9 +116,9 @@ class RoundTripTest : DescribeSpec({
                 description = null,
                 query = "find { Dashboard }",
                 dataSources = listOf(
-                    Stub("Static Data", "getConfig", StubMode.REQUEST_RESPONSE, """{ "theme": "dark" }""", null),
-                    Stub("Live Prices", "priceStream", StubMode.STREAM, null, listOf("""{ "price": 42 }""")),
-                    Stub("User Profile", "getUser", StubMode.REQUEST_RESPONSE, """{ "name": "Bob" }""", null)
+                    Stub("Static Data", "getConfig", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "theme": "dark" }""", messages = null),
+                    Stub("Live Prices", "priceStream", StubMode.STREAM, parameters = null, response = null, messages = listOf("""{ "price": 42 }""")),
+                    Stub("User Profile", "getUser", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "name": "Bob" }""", messages = null)
                 ),
                 expectedResult = """{ "theme": "dark", "price": 42, "name": "Bob" }""",
                 flow = null
@@ -126,5 +126,24 @@ class RoundTripTest : DescribeSpec({
             val roundTripped = TestSpecReader.read(TestSpecWriter.write(original))
             roundTripped shouldBe original
         }
+
+        it("round-trips a spec with stub parameters") {
+            val original = TestSpec(
+                specVersion = "0.1",
+                name = "Parameterised Test",
+                description = null,
+                query = "find { Product }",
+                dataSources = listOf(
+                    Stub("Get Product", "getProduct", StubMode.REQUEST_RESPONSE,
+                        parameters = """{ "productId": "PROD-1001" }""",
+                        response = """{ "productId": "PROD-1001", "name": "Laptop" }""",
+                        messages = null)
+                ),
+                expectedResult = """{ "productId": "PROD-1001", "name": "Laptop" }""",
+                flow = null
+            )
+            val roundTripped = TestSpecReader.read(TestSpecWriter.write(original))
+            roundTripped shouldBe original
+        }
     }
 })
diff --git a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt
similarity index 91%
rename from preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt
rename to preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt
index f1612e3..127cb78 100644
--- a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt
+++ b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecReaderTest.kt
@@ -394,6 +394,82 @@ class TestSpecReaderTest : DescribeSpec({
             spec.query shouldBe "find { Foo }"
         }
 
+        it("parses Request block as parameters") {
+            val markdown = """
+                |---
+                |spec-version: 0.1
+                |---
+                |
+                |# Test
+                |
+                |## Query
+                |
+                |```taxiql
+                |find { Foo }
+                |```
+                |
+                |## Data Sources
+                |
+                |### Get Product
+                |<!-- operation: getProduct -->
+                |
+                |Request:
+                |```json
+                |{ "productId": "PROD-1001" }
+                |```
+                |
+                |Response:
+                |```json
+                |{ "productId": "PROD-1001", "name": "Laptop" }
+                |```
+                |
+                |## Expected Result
+                |
+                |```json
+                |{ "productId": "PROD-1001", "name": "Laptop" }
+                |```
+            """.trimMargin()
+
+            val spec = TestSpecReader.read(markdown)
+            spec.dataSources[0].parameters shouldBe """{ "productId": "PROD-1001" }"""
+            spec.dataSources[0].response shouldBe """{ "productId": "PROD-1001", "name": "Laptop" }"""
+        }
+
+        it("parses stub without Request block as null parameters") {
+            val markdown = """
+                |---
+                |spec-version: 0.1
+                |---
+                |
+                |# Test
+                |
+                |## Query
+                |
+                |```taxiql
+                |find { Foo }
+                |```
+                |
+                |## Data Sources
+                |
+                |### Stub
+                |<!-- operation: getFoo -->
+                |
+                |Response:
+                |```json
+                |{}
+                |```
+                |
+                |## Expected Result
+                |
+                |```json
+                |{}
+                |```
+            """.trimMargin()
+
+            val spec = TestSpecReader.read(markdown)
+            spec.dataSources[0].parameters.shouldBeNull()
+        }
+
         it("parses Expected Results with no qualifier as JSON format") {
             val markdown = """
                 |---
diff --git a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt
similarity index 78%
rename from preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt
rename to preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt
index dafe786..0642998 100644
--- a/preflight-core/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt
+++ b/preflight-spec/src/test/kotlin/com/orbitalhq/preflight/spec/TestSpecWriterTest.kt
@@ -28,8 +28,8 @@ class TestSpecWriterTest : DescribeSpec({
         it("writes spec with multiple stubs") {
             val spec = minimalSpec().copy(
                 dataSources = listOf(
-                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null),
-                    Stub("Get Orders", "getOrders", StubMode.REQUEST_RESPONSE, """[{ "orderId": "A" }]""", null)
+                    Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null),
+                    Stub("Get Orders", "getOrders", StubMode.REQUEST_RESPONSE, parameters = null, response = """[{ "orderId": "A" }]""", messages = null)
                 )
             )
             val output = TestSpecWriter.write(spec)
@@ -42,7 +42,7 @@ class TestSpecWriterTest : DescribeSpec({
         it("writes stream-mode stub with mode directive present") {
             val spec = minimalSpec().copy(
                 dataSources = listOf(
-                    Stub("Price Stream", "priceStream", StubMode.STREAM, null, listOf("""{ "price": 100 }"""))
+                    Stub("Price Stream", "priceStream", StubMode.STREAM, parameters = null, response = null, messages = listOf("""{ "price": 100 }"""))
                 )
             )
             val output = TestSpecWriter.write(spec)
@@ -106,12 +106,35 @@ class TestSpecWriterTest : DescribeSpec({
             output shouldContain "```json typedInstance"
         }
 
+        it("writes Request block before Response when parameters are present") {
+            val spec = minimalSpec().copy(
+                dataSources = listOf(
+                    Stub("Get Product", "getProduct", StubMode.REQUEST_RESPONSE,
+                        parameters = """{ "productId": "PROD-1001" }""",
+                        response = """{ "productId": "PROD-1001", "name": "Laptop" }""",
+                        messages = null)
+                )
+            )
+            val output = TestSpecWriter.write(spec)
+            output shouldContain "Request:"
+            output shouldContain "Response:"
+            val requestIdx = output.indexOf("Request:")
+            val responseIdx = output.indexOf("Response:")
+            assert(requestIdx < responseIdx) { "Request should appear before Response" }
+        }
+
+        it("omits Request block when parameters are null") {
+            val spec = minimalSpec()
+            val output = TestSpecWriter.write(spec)
+            output shouldNotContain "Request:"
+        }
+
         it("writes stream stub with multiple messages in order") {
             val spec = minimalSpec().copy(
                 dataSources = listOf(
                     Stub(
-                        "Prices", "priceStream", StubMode.STREAM, null,
-                        listOf("""{ "price": 100 }""", """{ "price": 200 }""", """{ "price": 300 }""")
+                        "Prices", "priceStream", StubMode.STREAM, parameters = null, response = null,
+                        messages = listOf("""{ "price": 100 }""", """{ "price": 200 }""", """{ "price": 300 }""")
                     )
                 )
             )
@@ -130,7 +153,7 @@ class TestSpecWriterTest : DescribeSpec({
         it("writes stream stub with single message") {
             val spec = minimalSpec().copy(
                 dataSources = listOf(
-                    Stub("Stream", "myStream", StubMode.STREAM, null, listOf("""{ "value": 1 }"""))
+                    Stub("Stream", "myStream", StubMode.STREAM, parameters = null, response = null, messages = listOf("""{ "value": 1 }"""))
                 )
             )
             val output = TestSpecWriter.write(spec)
@@ -146,7 +169,7 @@ private fun minimalSpec() = TestSpec(
     description = null,
     query = "find { Customer }",
     dataSources = listOf(
-        Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, """{ "id": "1" }""", null)
+        Stub("Get Customer", "getCustomer", StubMode.REQUEST_RESPONSE, parameters = null, response = """{ "id": "1" }""", messages = null)
     ),
     expectedResult = """{ "id": "1" }""",
     flow = null
diff --git a/settings.gradle.kts b/settings.gradle.kts
index caa12ba..4fe330a 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -1,6 +1,7 @@
 rootProject.name = "preflight"
 
-// Include the plugin build as a composite
+// Include preflight-spec first so it's available when preflight-core resolves
+includeBuild("preflight-spec")
 includeBuild("preflight-core")
 
 // Include example projects as composites too