CI rehearsal only (do not merge)

.github/workflows/harness.yml

@@ -391,6 +391,14 @@ jobs:
         env:
           MPP_CONFORMANCE_LANGUAGES: kotlin
         run: pnpm exec vitest run test/conformance.test.ts
+      - name: Build and test the Kotlin protocol runner
+        working-directory: harness/kotlin-protocol-runner
+        run: gradle installDist test --no-daemon
+      - name: Run Kotlin mpp-protocol conformance vectors
+        working-directory: harness
+        env:
+          MPP_CONFORMANCE_LANGUAGES: kotlin
+        run: pnpm exec vitest run test/protocol-conformance.test.ts
       - name: Run Kotlin client harness smoke
         working-directory: harness
         run: pnpm exec vitest run test/e2e.test.ts --testNamePattern "kotlin client pays typescript server" --testTimeout 180000

.github/workflows/swift.yml

@@ -41,6 +41,13 @@ jobs:
         env:
           MPP_CONFORMANCE_LANGUAGES: swift
         run: pnpm exec vitest run test/conformance.test.ts
+      - name: Build Swift protocol runner
+        run: swift build -c release --product mpp-protocol-runner
+      - name: Run Swift mpp-protocol conformance vectors
+        working-directory: harness
+        env:
+          MPP_CONFORMANCE_LANGUAGES: swift
+        run: pnpm exec vitest run test/protocol-conformance.test.ts
       - name: Run Swift client harness smoke against TypeScript server
         working-directory: harness
         env:

Package.swift

@@ -35,10 +35,20 @@ let package = Package(
             dependencies: ["SolanaPayKit"],
             path: "swift/Sources/mpp-conformance"
         ),
+        .executableTarget(
+            name: "mpp-protocol-runner",
+            dependencies: ["SolanaPayKit"],
+            path: "swift/Sources/mpp-protocol-runner"
+        ),
         .testTarget(
             name: "SolanaPayKitTests",
             dependencies: ["SolanaPayKit"],
             path: "swift/Tests/SolanaPayKitTests"
         ),
+        .testTarget(
+            name: "MppProtocolRunnerTests",
+            dependencies: ["mpp-protocol-runner"],
+            path: "swift/Tests/MppProtocolRunnerTests"
+        ),
     ]
 )

harness/kotlin-protocol-runner/.gitignore

@@ -0,0 +1,2 @@
+.gradle/
+build/

harness/kotlin-protocol-runner/build.gradle.kts

@@ -0,0 +1,23 @@
+plugins {
+    kotlin("jvm") version "2.3.21"
+    application
+}
+
+dependencies {
+    // Path-included build, see settings.gradle.kts.
+    implementation("com.solana.paykit:solana-pay-kit-kotlin")
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.9.0")
+    testImplementation(kotlin("test"))
+}
+
+kotlin {
+    jvmToolchain(17)
+}
+
+application {
+    mainClass.set("com.solana.paykit.protocolrunner.MainKt")
+}
+
+tasks.test {
+    useJUnitPlatform()
+}

harness/kotlin-protocol-runner/settings.gradle.kts

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        mavenCentral()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        mavenCentral()
+    }
+}
+
+rootProject.name = "mpp-kotlin-protocol-runner"
+includeBuild("../../kotlin")

harness/kotlin-protocol-runner/src/main/kotlin/com/solana/paykit/protocolrunner/Main.kt

@@ -0,0 +1,91 @@
+// Kotlin mpp-protocol conformance runner.
+// Reads one adapter-ABI request on stdin and writes one response line on stdout,
+// per the contract in harness/src/protocol/runners/spawn.ts.
+package com.solana.paykit.protocolrunner
+
+import com.solana.paykit.protocols.mpp.core.MppHeaders
+import com.solana.paykit.protocols.mpp.core.PaymentChallenge
+import com.solana.paykit.protocols.mpp.core.PaymentCredential
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonNull
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+import kotlinx.serialization.json.put
+import java.util.Base64
+import kotlin.system.exitProcess
+
+private val families = mapOf(
+    "challenge.parse" to "parse_error",
+    "credential.parse" to "parse_error",
+    "receipt.parse" to "parse_error",
+    "challenge.format" to "format_error",
+    "credential.format" to "format_error",
+    "receipt.format" to "format_error",
+    "base64url.encode" to "encoding_error",
+    "base64url.decode" to "encoding_error",
+    "challenge.id" to "generation_error",
+)
+
+private val sdkGaps = families.keys - setOf("challenge.parse", "credential.format")
+
+fun main() {
+    val response = reply(System.`in`.readBytes().decodeToString())
+    println(response)
+    if (response["error_type"] == JsonPrimitive("runner_error")) exitProcess(1)
+}
+
+internal fun respond(line: String): String = reply(line).toString()
+
+private fun reply(line: String): JsonObject {
+    val (op, input) = try {
+        val request = Json.parseToJsonElement(line).jsonObject
+        request["op"]?.jsonPrimitive?.content.orEmpty() to (request["input"] ?: JsonNull)
+    } catch (error: IllegalArgumentException) {
+        return fail(error.message, "runner_error")
+    }
+    val family = families[op] ?: return fail("unknown operation: $op", "unsupported_operation")
+    if (op in sdkGaps) return fail("$op unsupported by the Kotlin SDK", family)
+    return try {
+        val result = if (op == "challenge.parse") parseChallenge(input) else formatCredential(input)
+        buildJsonObject {
+            put("success", true)
+            put("result", result)
+        }
+    } catch (error: Exception) {
+        fail(error.message, family)
+    }
+}
+
+private fun fail(error: String?, errorType: String) = buildJsonObject {
+    put("success", false)
+    put("error", error)
+    put("error_type", errorType)
+}
+
+private fun parseChallenge(input: JsonElement): JsonObject {
+    val challenge = MppHeaders.parseWWWAuthenticate(input.jsonObject.getValue("header").jsonPrimitive.content)
+    val fields = Json.encodeToJsonElement(PaymentChallenge.serializer(), challenge).jsonObject
+    return JsonObject(
+        fields.filter { (name, value) -> name !in setOf("expires", "digest") || value != JsonPrimitive("") }.mapValues { (name, value) ->
+            if (name == "request" || name == "opaque") decodeJson(value.jsonPrimitive.content) else value
+        },
+    )
+}
+
+private fun decodeJson(base64Url: String): JsonElement =
+    Json.parseToJsonElement(Base64.getUrlDecoder().decode(base64Url).decodeToString())
+
+private fun formatCredential(input: JsonElement): JsonObject {
+    val credential = input.jsonObject
+    val challenge = credential.getValue("challenge").jsonObject
+    val request = (challenge["request"] ?: JsonObject(emptyMap())).toString().encodeToByteArray()
+    val echo = challenge + ("request" to JsonPrimitive(Base64.getUrlEncoder().withoutPadding().encodeToString(request)))
+    val wire = JsonObject(credential + ("challenge" to JsonObject(echo)))
+    return buildJsonObject {
+        put("header", MppHeaders.formatAuthorization(Json.decodeFromJsonElement(PaymentCredential.serializer(), wire)))
+    }
+}

harness/kotlin-protocol-runner/src/test/kotlin/com/solana/paykit/protocolrunner/MainTest.kt

@@ -0,0 +1,101 @@
+package com.solana.paykit.protocolrunner
+
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+import kotlinx.serialization.json.put
+import kotlinx.serialization.json.putJsonObject
+import java.util.Base64
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class MainTest {
+    private fun answer(line: String): JsonObject {
+        val output = respond(line)
+        assertFalse('\n' in output)
+        return Json.parseToJsonElement(output).jsonObject
+    }
+
+    private fun JsonObject.field(name: String) = getValue(name).jsonPrimitive.content
+
+    @Test
+    fun parsesBasicChallengeWithRequestObject() {
+        val request = """{"amount":"1000000","currency":"0x20c0000000000000000000000000000000000001","recipient":"0x1234567890abcdef1234567890abcdef12345678"}"""
+        val encoded = Base64.getUrlEncoder().withoutPadding().encodeToString(request.encodeToByteArray())
+        val line = buildJsonObject {
+            put("op", "challenge.parse")
+            putJsonObject("input") {
+                put("header", """Payment id="ch_abc123", realm="api.example.com", method="tempo", intent="charge", request="$encoded"""")
+            }
+        }.toString()
+
+        val response = answer(line)
+
+        assertEquals("true", response.field("success"))
+        assertEquals(
+            Json.parseToJsonElement("""{"id":"ch_abc123","realm":"api.example.com","method":"tempo","intent":"charge","request":$request}"""),
+            response["result"],
+        )
+    }
+
+    @Test
+    fun dropsEmptyOptionalField() {
+        val header = """Payment id="ch", realm="r", method="tempo", intent="charge", request="e30", expires="""""
+        val line = buildJsonObject {
+            put("op", "challenge.parse")
+            putJsonObject("input") { put("header", header) }
+        }.toString()
+
+        assertEquals(
+            Json.parseToJsonElement("""{"id":"ch","realm":"r","method":"tempo","intent":"charge","request":{}}"""),
+            answer(line)["result"],
+        )
+    }
+
+    @Test
+    fun emptyRequestIsAParseError() {
+        val header = """Payment id="ch", realm="r", method="tempo", intent="charge", request="""""
+        val line = buildJsonObject {
+            put("op", "challenge.parse")
+            putJsonObject("input") { put("header", header) }
+        }.toString()
+
+        val response = answer(line)
+
+        assertEquals("false", response.field("success"))
+        assertEquals("parse_error", response.field("error_type"))
+    }
+
+    @Test
+    fun refusesNonJson() {
+        assertEquals("runner_error", answer("not json").field("error_type"))
+    }
+
+    @Test
+    fun unknownOpIsUnsupportedOperation() {
+        assertEquals("unsupported_operation", answer("""{"op":"nope.op","input":{}}""").field("error_type"))
+    }
+
+    @Test
+    fun sdkGapAnswersItsFamilyErrorType() {
+        val response = answer("""{"op":"receipt.parse","input":{"header":"x"}}""")
+
+        assertEquals("false", response.field("success"))
+        assertEquals("parse_error", response.field("error_type"))
+        assertTrue("unsupported" in response.field("error"))
+    }
+
+    @Test
+    fun credentialPayloadHashIsAFormatError() {
+        val credential = """{"challenge":{"id":"ch","realm":"r","method":"tempo","intent":"charge","request":{}},"payload":{"type":"hash","hash":"0x12"}}"""
+
+        val response = answer("""{"op":"credential.format","input":$credential}""")
+
+        assertEquals("format_error", response.field("error_type"))
+        assertTrue("unknown key 'hash'" in response.field("error"))
+    }
+}

harness/protocol-runners/kotlin.json

@@ -0,0 +1,5 @@
+{
+  "language": "kotlin",
+  "command": ["sh", "-c", "exec build/install/mpp-kotlin-protocol-runner/bin/mpp-kotlin-protocol-runner"],
+  "cwd": "harness/kotlin-protocol-runner"
+}

harness/protocol-runners/swift.json

@@ -0,0 +1,5 @@
+{
+  "language": "swift",
+  "command": ["swift", "run", "-c", "release", "mpp-protocol-runner"],
+  "cwd": "swift"
+}

harness/src/protocol/runners/spawn.ts

@@ -82,7 +82,15 @@ export function spawnedProtocolAdapter(runner: DiscoveredProtocolRunner): Protoc
         child.on("error", (err) => {
           resolve({ success: false, error: `spawn failed: ${err.message}`, error_type: "runner_error" });
         });
-        child.on("close", () => {
+        child.on("close", (code) => {
+          if (code !== 0) {
+            resolve({
+              success: false,
+              error: `runner exited ${code}; stderr: ${stderr.slice(-512)}`,
+              error_type: "runner_error",
+            });
+            return;
+          }
           const line = stdout.trim().split("\n").filter(Boolean).pop();
           if (!line) {
             resolve({