Merge remote-tracking branch 'origin/master' into codex/project-instruction-files

# Conflicts:
#	AGENTS.md
#	docs/config-catalog.md
#	docs/cordis-catalog/events.md
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/core.md
#	docs/event-producer-consumer.md
#	docs/persistence-catalog.md
#	docs/rfc/implemented/architecture/2026-07-05-reconstructable-requests.md
#	docs/rfc/implemented/feature/2026-06-15-code-mode.md
#	docs/rfc/implemented/feature/2026-06-30-hook-bridges.md
#	docs/rfc/implemented/feature/2026-06-30-interception-seams.md
#	docs/rfc/implemented/feature/2026-07-08-repeat-tool-guard.md
#	docs/rfc/proposed/simplification/2026-07-04-prune-dead-core-spine-surface.md
#	examples/AGENTS.md
#	examples/acp-agent/cordis.yml
#	examples/acp-agent/tests/acp.snapshot.ts
#	examples/echo-agent/cordis.yml
#	examples/sandbox-acp-agent/cordis.yml
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/agent-core/README.md
#	packages/core/agent-core/src/index.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/loop.ts
#	packages/core/agent-loop/tests/interception.spec.ts
#	packages/core/agent/src/types.ts
#	packages/core/tools/README.md
#	packages/core/tools/src/code-mode.ts
#	packages/core/tools/src/index.ts
#	packages/fs/fs-local/src/index.ts
#	packages/fs/fs/README.md
#	packages/fs/fs/src/index.ts
#	packages/guard/repeat-tool-guard/README.md
#	packages/guard/repeat-tool-guard/src/index.ts
#	packages/hooks/hooks-claude/src/index.ts
#	packages/hooks/hooks-codex/src/index.ts
#	packages/ui/acp-agent/src/index.ts

packages/ui/jsonrpc/tests/plugin-apply.spec.ts

@@ -0,0 +1,293 @@
+import { createServer } from 'node:http'
+import type { IncomingMessage, Server, ServerResponse } from 'node:http'
+import { mkdtemp, rm } from 'node:fs/promises'
+import { join } from 'node:path'
+import { tmpdir } from 'node:os'
+import { PassThrough, Writable } from 'node:stream'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { Context } from 'cordis'
+import * as agentCore from '@deepseek-ai/dsh-agent-core'
+import SessionPersistenceJsonl from '@deepseek-ai/dsh-session-persistence-jsonl'
+import * as jsonrpc from '../src/index.ts'
+
+/**
+ * Mount the real namespace plugin with in-memory stdio and exit seams. Covers
+ * the full transport/server path, response-before-exit shutdown exactly once,
+ * and bare-fiber disposal without process exit.
+ */
+
+/** One ordered frame, write completion, or exit observation. */
+type WireEvent =
+  | { kind: 'frame'; frame: Record<string, unknown> }
+  | { kind: 'write-complete'; ids: (string | number)[] }
+  | { kind: 'exit'; code: number }
+
+interface ApplyHarness {
+  ctx: Context
+  /** The plugin fiber used by the bare-dispose case. */
+  fiber: Awaited<ReturnType<Context['plugin']>>
+  /** Frames, write completions, and exits in observation order. */
+  events: WireEvent[]
+  outputErrors: Error[]
+  send(frame: Record<string, unknown>): void
+  sendRaw(text: string): void
+  frames(): Record<string, unknown>[]
+  exits(): number[]
+  waitForFrame(predicate: (frame: Record<string, unknown>) => boolean, description: string): Promise<Record<string, unknown>>
+  dispose(): Promise<void>
+}
+
+/** Poll asynchronous output for up to five seconds. */
+async function waitFor<T>(get: () => T | undefined, description: string): Promise<T> {
+  const deadline = Date.now() + 5000
+  for (;;) {
+    const value = get()
+    if (value !== undefined) return value
+    if (Date.now() > deadline) throw new Error(`timed out waiting for ${description}`)
+    await new Promise(resolve => setTimeout(resolve, 5))
+  }
+}
+
+/** Drain asynchronous work before a negative assertion. */
+async function settle(): Promise<void> {
+  await new Promise(resolve => setTimeout(resolve, 25))
+}
+
+/** Mount the real plugin on a minimal harness with in-memory stdio and exit. */
+async function mountPlugin(
+  storageDir: string,
+  options: { writeDelayMs?: number; failFlush?: boolean } = {},
+): Promise<ApplyHarness> {
+  const ctx = new Context()
+  await ctx.plugin(agentCore, { workspaceContext: false })
+  await ctx.plugin(SessionPersistenceJsonl, { root: storageDir })
+  await new Promise(resolve => setTimeout(resolve, 50))
+
+  const input = new PassThrough()
+  const events: WireEvent[] = []
+  const outputErrors: Error[] = []
+  let pendingOutput = ''
+  // Record frame admission separately from write completion so delayed output
+  // tests the flush barrier.
+  const output = new Writable({
+    write(chunk: Buffer, _encoding, callback) {
+      const ids: (string | number)[] = []
+      pendingOutput += chunk.toString('utf8')
+      for (;;) {
+        const newline = pendingOutput.indexOf('\n')
+        if (newline < 0) break
+        const line = pendingOutput.slice(0, newline).trim()
+        pendingOutput = pendingOutput.slice(newline + 1)
+        if (line) {
+          const frame = JSON.parse(line) as Record<string, unknown>
+          events.push({ kind: 'frame', frame })
+          if (typeof frame.id === 'string' || typeof frame.id === 'number') ids.push(frame.id)
+        }
+      }
+      const complete = (): void => {
+        if (options.failFlush === true && chunk.length === 0) {
+          callback(new Error('flush callback failed'))
+          return
+        }
+        events.push({ kind: 'write-complete', ids })
+        callback()
+      }
+      if ((options.writeDelayMs ?? 0) > 0) setTimeout(complete, options.writeDelayMs)
+      else complete()
+    },
+  })
+  output.on('error', (error: Error) => { outputErrors.push(error) })
+  const exit = (code: number): void => { events.push({ kind: 'exit', code }) }
+
+  const fiber = await ctx.plugin(jsonrpc, { input, output, exit })
+
+  const frames = (): Record<string, unknown>[] =>
+    events.flatMap(event => event.kind === 'frame' ? [event.frame] : [])
+  return {
+    ctx,
+    fiber,
+    events,
+    outputErrors,
+    send: (frame) => { input.write(`${JSON.stringify(frame)}\n`) },
+    sendRaw: (text) => { input.write(text) },
+    frames,
+    exits: () => events.flatMap(event => event.kind === 'exit' ? [event.code] : []),
+    waitForFrame: (predicate, description) => waitFor(() => frames().find(predicate), description),
+    dispose: async () => { await ctx.fiber.dispose() },
+  }
+}
+
+const servers: Server[] = []
+
+afterEach(async () => {
+  await Promise.all(servers.splice(0).map(server => new Promise(resolve => server.close(resolve))))
+  vi.unstubAllEnvs()
+})
+
+/** Keyless SSE endpoint for completing a prompt turn. */
+async function mockCompletionServer(): Promise<{ url: string; requests: unknown[] }> {
+  const requests: unknown[] = []
+  const server = createServer((request: IncomingMessage, response: ServerResponse) => {
+    let body = ''
+    request.on('data', (chunk: Buffer) => { body += chunk.toString('utf8') })
+    request.on('end', () => {
+      requests.push(JSON.parse(body))
+      response.writeHead(200, { 'content-type': 'text/event-stream' })
+      response.write('data: {"choices":[{"delta":{"role":"assistant","content":null,"reasoning_content":""}}]}\n\n')
+      response.write('data: {"choices":[{"delta":{"content":"done"}}]}\n\n')
+      response.write('data: {"choices":[{"delta":{"content":""},"finish_reason":"stop"}],"usage":{"prompt_tokens":3,"completion_tokens":1}}\n\n')
+      response.write('data: [DONE]\n\n')
+      response.end()
+    })
+  })
+  servers.push(server)
+  await new Promise<void>(resolve => server.listen(0, '127.0.0.1', resolve))
+  const address = server.address()
+  if (address === null || typeof address === 'string') throw new Error('no port')
+  return { url: `http://127.0.0.1:${address.port}`, requests }
+}
+
+describe('dsh-jsonrpc plugin apply', () => {
+  it('serves initialize over the injected stdio pair', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-apply-init-'))
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    const harness = await mountPlugin(storageDir)
+    try {
+      harness.send({ jsonrpc: '2.0', id: 'init-1', method: 'initialize', params: { cwd: storageDir, model: 'apply-model' } })
+
+      const response = await harness.waitForFrame(frame => frame.id === 'init-1', 'initialize response')
+      expect(response).toEqual({
+        jsonrpc: '2.0',
+        id: 'init-1',
+        result: { serverInfo: { name: 'deepseek-harness-sdk-runtime', version: '0.0.1' } },
+      })
+      expect(harness.exits()).toEqual([])
+    } finally {
+      await harness.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('drives a session/prompt turn end-to-end and forwards session notifications as output frames', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-apply-prompt-'))
+    const llmServer = await mockCompletionServer()
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    vi.stubEnv('DEEPSEEK_BASE_URL', llmServer.url)
+    const harness = await mountPlugin(storageDir)
+    try {
+      harness.send({ jsonrpc: '2.0', id: 1, method: 'initialize', params: { cwd: storageDir, model: 'dsagent-model' } })
+      await harness.waitForFrame(frame => frame.id === 1, 'initialize response')
+
+      harness.send({
+        jsonrpc: '2.0',
+        id: 2,
+        method: 'session/prompt',
+        params: { sessionId: 'main', contentBlocks: [{ type: 'text', text: 'fix it' }] },
+      })
+      const response = await harness.waitForFrame(frame => frame.id === 2, 'prompt response')
+      expect(response.result).toEqual({ accepted: true })
+
+      expect(llmServer.requests).toHaveLength(1)
+      const body = llmServer.requests[0] as { model: string; messages: { role: string }[] }
+      expect(body.model).toBe('dsagent-model')
+      expect(body.messages.at(-1)?.role).toBe('user')
+
+      // Notifications use the same transport and arrive as id-less frames.
+      const notifications = harness.frames().filter(frame => frame.id === undefined)
+      expect(notifications.some(frame => frame.method === 'session.event')).toBe(true)
+      expect(notifications.find(frame => frame.method === 'session.finished')).toMatchObject({
+        jsonrpc: '2.0',
+        params: { sessionId: 'main', status: 'ok' },
+      })
+    } finally {
+      await harness.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('answers shutdown before exiting 0 exactly once, even against a racing second shutdown', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-apply-shutdown-'))
+    const harness = await mountPlugin(storageDir, { writeDelayMs: 10 })
+    try {
+      // One chunk makes the two deferred exit callbacks race.
+      const first = { jsonrpc: '2.0', id: 'sd-1', method: 'shutdown' }
+      const second = { jsonrpc: '2.0', id: 'sd-2', method: 'shutdown' }
+      harness.sendRaw(`${JSON.stringify(first)}\n${JSON.stringify(second)}\n`)
+
+      await waitFor(() => harness.exits().length > 0 ? true : undefined, 'exit recorder call')
+      expect(harness.exits()).toEqual([0])
+
+      // Both response writes and the flush barrier complete before exit.
+      const exitIndex = harness.events.findIndex(event => event.kind === 'exit')
+      const firstResponse = harness.events.findIndex(event => event.kind === 'frame' && event.frame.id === 'sd-1')
+      const secondResponse = harness.events.findIndex(event => event.kind === 'frame' && event.frame.id === 'sd-2')
+      const firstComplete = harness.events.findIndex(event => event.kind === 'write-complete' && event.ids.includes('sd-1'))
+      const secondComplete = harness.events.findIndex(event => event.kind === 'write-complete' && event.ids.includes('sd-2'))
+      const flushComplete = harness.events.findIndex(event => event.kind === 'write-complete' && event.ids.length === 0)
+      expect(firstResponse).toBeGreaterThanOrEqual(0)
+      expect(secondResponse).toBeGreaterThanOrEqual(0)
+      expect(firstComplete).toBeGreaterThan(firstResponse)
+      expect(secondComplete).toBeGreaterThan(secondResponse)
+      expect(flushComplete).toBeGreaterThan(firstComplete)
+      expect(flushComplete).toBeGreaterThan(secondComplete)
+      expect(exitIndex).toBeGreaterThan(flushComplete)
+
+      await settle()
+      expect(harness.exits()).toEqual([0])
+
+      const before = harness.frames().length
+      harness.send({ jsonrpc: '2.0', id: 'after-exit', method: 'initialize', params: { cwd: storageDir, model: 'x' } })
+      await settle()
+      expect(harness.frames().length).toBe(before)
+    } finally {
+      await harness.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('still disposes and exits once when the flush callback fails', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-apply-flush-failure-'))
+    const harness = await mountPlugin(storageDir, { failFlush: true })
+    try {
+      harness.send({ jsonrpc: '2.0', id: 'sd-fail', method: 'shutdown' })
+
+      await waitFor(() => harness.exits().length > 0 ? true : undefined, 'exit after flush failure')
+      await settle()
+      expect(harness.exits()).toEqual([0])
+      expect(harness.outputErrors.map(error => error.message)).toEqual(['flush callback failed'])
+
+      const before = harness.frames().length
+      harness.send({ jsonrpc: '2.0', id: 'after-flush-failure', method: 'initialize', params: { cwd: storageDir, model: 'x' } })
+      await settle()
+      expect(harness.frames().length).toBe(before)
+    } finally {
+      await harness.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('stops serving on a bare fiber dispose (HMR-style unload) without calling exit', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-apply-dispose-'))
+    const harness = await mountPlugin(storageDir)
+    try {
+      // Prove the handler-rejection path is live before disposal.
+      harness.send({ jsonrpc: '2.0', id: 'probe-1', method: 'nope/unknown' })
+      const error = await harness.waitForFrame(frame => frame.id === 'probe-1', 'error response for unknown method')
+      expect(error.error).toMatchObject({
+        code: -32603,
+        message: 'unknown DeepSeek Harness SDK runtime method: nope/unknown',
+      })
+
+      await harness.fiber.dispose()
+
+      const before = harness.frames().length
+      harness.send({ jsonrpc: '2.0', id: 'probe-2', method: 'initialize', params: { cwd: storageDir, model: 'x' } })
+      await settle()
+      expect(harness.frames().length).toBe(before)
+      expect(harness.exits()).toEqual([])
+    } finally {
+      await harness.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+})

packages/ui/jsonrpc/tests/plugin-shape.spec.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest'
+import Loader from '@cordisjs/plugin-loader'
+import * as jsonrpc from '../src/index.ts'
+
+/**
+ * Run the real namespace export through `Loader.unwrapExports`; a stray
+ * default would discard `name`, `inject`, `Config`, and `apply`.
+ */
+describe('dsh-jsonrpc plugin export shape', () => {
+  it('has the namespace-plugin export shape (no stray default) so the Loader keeps name/inject/Config/apply', () => {
+    expect('default' in jsonrpc).toBe(false)
+    expect(typeof jsonrpc.apply).toBe('function')
+
+    const loader = Object.create(Loader.prototype) as Loader
+    const unwrapped = loader.unwrapExports(jsonrpc) as Record<string, unknown>
+    expect(unwrapped).toBe(jsonrpc)
+    expect(unwrapped.name).toBe('jsonrpc')
+    expect(unwrapped.inject).toEqual(['agents'])
+    expect(unwrapped.Config).toBeDefined()
+    expect(typeof unwrapped.apply).toBe('function')
+  })
+})

packages/ui/jsonrpc/tests/server.spec.ts

@@ -0,0 +1,572 @@
+import { createServer } from 'node:http'
+import type { IncomingMessage, Server, ServerResponse } from 'node:http'
+import { mkdtemp, rm } from 'node:fs/promises'
+import { join } from 'node:path'
+import { tmpdir } from 'node:os'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { Context } from 'cordis'
+import { AgentId, type Agent, type AgentHandle } from '@deepseek-ai/dsh-agent'
+import { SessionId } from '@deepseek-ai/dsh-session'
+import * as agentCore from '@deepseek-ai/dsh-agent-core'
+import SessionPersistenceJsonl from '@deepseek-ai/dsh-session-persistence-jsonl'
+import * as LlmDeepSeek from '@deepseek-ai/dsh-llm-deepseek'
+import SubagentService, { type SubagentRunEndInfo } from '@deepseek-ai/dsh-subagent'
+import { HarnessSdkServer, type JsonRpcTransportPeer } from '../src/index.ts'
+
+class FakeTransport implements JsonRpcTransportPeer {
+  notifications: { method: string; params?: Record<string, unknown> }[] = []
+
+  async request(method: string, params: Record<string, unknown>): Promise<unknown> {
+    throw new Error(`the SDK server should not call host JSON-RPC method ${method} with ${JSON.stringify(params)}`)
+  }
+
+  notify(method: string, params?: Record<string, unknown>): void {
+    this.notifications.push(params === undefined ? { method } : { method, params })
+  }
+}
+
+const servers: Server[] = []
+
+afterEach(async () => {
+  await Promise.all(servers.splice(0).map(server => new Promise(resolve => server.close(resolve))))
+  vi.unstubAllEnvs()
+})
+
+async function mockCompletionServer(): Promise<{ url: string; requests: unknown[]; headers: IncomingMessage['headers'][] }> {
+  const requests: unknown[] = []
+  const headers: IncomingMessage['headers'][] = []
+  const server = createServer((request: IncomingMessage, response: ServerResponse) => {
+    let body = ''
+    request.on('data', (chunk: Buffer) => { body += chunk.toString('utf8') })
+    request.on('end', () => {
+      requests.push(JSON.parse(body))
+      headers.push(request.headers)
+      response.writeHead(200, { 'content-type': 'text/event-stream' })
+      response.write('data: {"choices":[{"delta":{"role":"assistant","content":null,"reasoning_content":""}}]}\n\n')
+      response.write('data: {"choices":[{"delta":{"content":"done"}}]}\n\n')
+      response.write('data: {"choices":[{"delta":{"content":""},"finish_reason":"stop"}],"usage":{"prompt_tokens":3,"completion_tokens":1}}\n\n')
+      response.write('data: [DONE]\n\n')
+      response.end()
+    })
+  })
+  servers.push(server)
+  await new Promise<void>(resolve => server.listen(0, '127.0.0.1', resolve))
+  const address = server.address()
+  if (address === null || typeof address === 'string') throw new Error('no port')
+  return { url: `http://127.0.0.1:${address.port}`, requests, headers }
+}
+
+async function makeHarness(storageDir: string) {
+  const ctx = new Context()
+  await ctx.plugin(agentCore, { workspaceContext: false })
+  await ctx.plugin(SubagentService)
+  await ctx.plugin(SessionPersistenceJsonl, { root: storageDir })
+  await new Promise(resolve => setTimeout(resolve, 50))
+  return ctx
+}
+
+/** Drive the owning service so test lifecycle events carry the real parent scope. */
+async function settleSubagent(ctx: Context, parent: Agent, info: SubagentRunEndInfo): Promise<void> {
+  const disposeProvider = ctx.subagents.registerProvider({
+    name: info.provider,
+    capabilities: { outputSchema: false, depthLimit: false, toolFilter: false, persona: false },
+    inheritsParentContext: false,
+    async start() {
+      return {
+        id: info.id,
+        result: info.lastAssistantMessage === undefined
+          ? Promise.reject(new Error('synthetic infrastructure failure'))
+          : Promise.resolve({ output: info.lastAssistantMessage, stopReason: info.stopReason }),
+        dispose: () => Promise.resolve(),
+      }
+    },
+  })
+  try {
+    const run = await ctx.subagents.start(info.provider, {
+      parent,
+      prompt: [],
+      signal: new AbortController().signal,
+    })
+    await run.result.then(() => undefined, () => undefined)
+    await run.dispose()
+  } finally {
+    disposeProvider()
+  }
+}
+
+describe('HarnessSdkServer', () => {
+  it('creates a harness agent and calls the configured OpenAI-compatible endpoint', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-'))
+    const llmServer = await mockCompletionServer()
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    vi.stubEnv('DEEPSEEK_BASE_URL', llmServer.url)
+    const ctx = await makeHarness(storageDir)
+    try {
+      const transport = new FakeTransport()
+      const server = new HarnessSdkServer(ctx, transport)
+
+      const init = await server.handleRequest('initialize', {
+        cwd: storageDir,
+        model: 'dsagent-model',
+      }) as { serverInfo: { name: string } }
+      expect(init.serverInfo.name).toBe('deepseek-harness-sdk-runtime')
+
+      await server.handleRequest('session/prompt', {
+        sessionId: 'main',
+        contentBlocks: [{ type: 'text', text: 'fix it' }],
+      })
+
+      expect(llmServer.requests).toHaveLength(1)
+      const body = llmServer.requests[0] as { model: string; messages: { role: string }[] }
+      expect(body.model).toBe('dsagent-model')
+      expect(body.messages[0]?.role).toBe('system')
+      expect(body.messages.at(-1)?.role).toBe('user')
+      expect(llmServer.headers[0]?.authorization).toBe('Bearer test-key')
+      expect(transport.notifications.some(n => n.method === 'session.event')).toBe(true)
+      expect(transport.notifications.at(-1)).toMatchObject({
+        method: 'session.finished',
+        params: { sessionId: 'main', status: 'ok' },
+      })
+
+      await server.handleRequest('session/prompt', {
+        sessionId: 'main',
+        contentBlocks: [{ type: 'text', text: 'again' }],
+      })
+      expect(llmServer.requests).toHaveLength(2)
+
+      const orphanHandle = await ctx.agents.create({
+        agentId: AgentId('orphan-agent'),
+        sessionId: SessionId('orphan-session'),
+        meta: { cwd: storageDir },
+        agentOptions: { model: 'dsagent-model' },
+      })
+      orphanHandle.agent.send([{ type: 'text', text: 'outside the sdk session map' }])
+      await orphanHandle.agent.whenIdle()
+      await orphanHandle.dispose()
+      expect(llmServer.requests).toHaveLength(3)
+
+      await server.handleRequest('shutdown', undefined)
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('rejects overlapping prompts for one session without serializing other sessions', async () => {
+    let releaseMain: (() => void) | undefined
+    const firstMainIdle = new Promise<void>((resolve) => { releaseMain = resolve })
+    const mainWhenIdle = vi.fn<() => Promise<void>>()
+      .mockReturnValueOnce(firstMainIdle)
+      .mockResolvedValue(undefined)
+    const mainSend = vi.fn()
+    const mainAgent = {
+      send: mainSend,
+      whenIdle: mainWhenIdle,
+    } as unknown as Agent
+    const otherSend = vi.fn()
+    const otherAgent = {
+      send: otherSend,
+      whenIdle: vi.fn(() => Promise.resolve()),
+    } as unknown as Agent
+    const mainHandle = { agent: mainAgent, dispose: vi.fn(() => Promise.resolve()) }
+    const otherHandle = { agent: otherAgent, dispose: vi.fn(() => Promise.resolve()) }
+    const create = vi.fn(async (options: { agentId: AgentId }) =>
+      String(options.agentId) === 'main' ? mainHandle : otherHandle)
+    const ctx = {
+      on: vi.fn(() => () => undefined),
+      agents: { create, get: () => undefined },
+      get: () => undefined,
+    } as unknown as Context
+    const server = new HarnessSdkServer(ctx, new FakeTransport())
+    const prompt = (sessionId: string, text: string) => server.prompt({
+      sessionId,
+      contentBlocks: [{ type: 'text', text }],
+    })
+
+    const first = prompt('main', 'first')
+    await vi.waitFor(() => { expect(mainSend).toHaveBeenCalledOnce() })
+
+    await expect(prompt('main', 'overlap')).rejects.toThrow('session already has an active prompt: main')
+    await expect(prompt('other', 'independent')).resolves.toEqual({ accepted: true })
+    releaseMain?.()
+    await expect(first).resolves.toEqual({ accepted: true })
+    await expect(prompt('main', 'sequential')).resolves.toEqual({ accepted: true })
+
+    mainWhenIdle.mockRejectedValueOnce(new Error('turn wait failed'))
+    await expect(prompt('main', 'failing')).rejects.toThrow('turn wait failed')
+    await expect(prompt('main', 'after failure')).resolves.toEqual({ accepted: true })
+
+    expect(mainSend).toHaveBeenCalledTimes(4)
+    expect(otherSend).toHaveBeenCalledOnce()
+    await server.shutdown()
+    expect(mainHandle.dispose).toHaveBeenCalledOnce()
+    expect(otherHandle.dispose).toHaveBeenCalledOnce()
+  })
+
+  it('notifies the host when a child session is created with parent lineage', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-subagent-'))
+    const ctx = await makeHarness(storageDir)
+    try {
+      const transport = new FakeTransport()
+      const server = new HarnessSdkServer(ctx, transport)
+
+      ctx.sessions.create(SessionId('root-session'), {
+        meta: { cwd: storageDir },
+      })
+      ctx.sessions.create(SessionId('child-session'), {
+        meta: { cwd: storageDir, parentSession: SessionId('main') },
+      })
+
+      expect(transport.notifications).toContainEqual({
+        method: 'subagent.started',
+        params: {
+          parentSessionId: 'main',
+          childSessionId: 'child-session',
+        },
+      })
+
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('creates an SDK session without an optional system prompt', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-no-system-'))
+    const llmServer = await mockCompletionServer()
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    vi.stubEnv('DEEPSEEK_BASE_URL', llmServer.url)
+    const ctx = await makeHarness(storageDir)
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport())
+
+      await server.initialize({ cwd: storageDir, model: 'plain-model' })
+      await server.prompt({
+        sessionId: 'plain',
+        contentBlocks: [{ type: 'text', text: 'hello' }],
+      })
+
+      expect(llmServer.requests).toHaveLength(1)
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('notifies the host when a subagent run settles', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-subagent-end-'))
+    const ctx = await makeHarness(storageDir)
+    try {
+      const transport = new FakeTransport()
+      const server = new HarnessSdkServer(ctx, transport)
+
+      const parentHandle = await ctx.agents.create({
+        agentId: AgentId('parent-agent'),
+        sessionId: SessionId('main'),
+        meta: { cwd: storageDir },
+        agentOptions: { model: 'deepseek' },
+      })
+      const handle = await ctx.agents.create({
+        agentId: AgentId('child-agent'),
+        sessionId: SessionId('child-session'),
+        meta: { cwd: storageDir, parentSession: SessionId('main') },
+        agentOptions: { model: 'deepseek' },
+      })
+      await settleSubagent(ctx, parentHandle.agent, {
+        provider: 'spawn',
+        id: AgentId('child-agent'),
+        stopReason: 'completed',
+        lastAssistantMessage: [{ type: 'text', text: 'child done' }],
+      })
+
+      expect(transport.notifications).toContainEqual({
+        method: 'subagent.finished',
+        params: {
+          provider: 'spawn',
+          agentId: 'child-agent',
+          parentSessionId: 'main',
+          childSessionId: 'child-session',
+          status: 'ok',
+          stopReason: 'completed',
+          lastAssistantMessage: [{ type: 'text', text: 'child done' }],
+        },
+      })
+
+      await handle.dispose()
+      await parentHandle.dispose()
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('falls back to live agent lineage for uncached subagent end events', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-subagent-fallback-'))
+    const ctx = await makeHarness(storageDir)
+    let parentHandle: AgentHandle | undefined
+    let handle: AgentHandle | undefined
+    let failedHandle: AgentHandle | undefined
+    try {
+      parentHandle = await ctx.agents.create({
+        agentId: AgentId('fallback-parent-agent'),
+        sessionId: SessionId('fallback-parent'),
+        meta: { cwd: storageDir },
+        agentOptions: { model: 'deepseek' },
+      })
+      handle = await ctx.agents.create({
+        agentId: AgentId('fallback-child-agent'),
+        sessionId: SessionId('fallback-child-session'),
+        meta: { cwd: storageDir, parentSession: SessionId('fallback-parent') },
+        agentOptions: { model: 'deepseek' },
+      })
+      failedHandle = await ctx.agents.create({
+        agentId: AgentId('failed-child-agent'),
+        sessionId: SessionId('failed-child-session'),
+        meta: { cwd: storageDir },
+        agentOptions: { model: 'deepseek' },
+      })
+      const transport = new FakeTransport()
+      const server = new HarnessSdkServer(ctx, transport)
+
+      await settleSubagent(ctx, parentHandle.agent, {
+        provider: 'fork',
+        id: AgentId('fallback-child-agent'),
+        stopReason: 'max-tokens',
+        lastAssistantMessage: [],
+      })
+      await settleSubagent(ctx, parentHandle.agent, {
+        provider: 'fork',
+        id: AgentId('failed-child-agent'),
+        stopReason: 'error',
+      })
+      await settleSubagent(ctx, parentHandle.agent, {
+        provider: 'fork',
+        id: AgentId('missing-child-agent'),
+        stopReason: 'error',
+      })
+
+      expect(transport.notifications).toContainEqual({
+        method: 'subagent.finished',
+        params: {
+          provider: 'fork',
+          agentId: 'fallback-child-agent',
+          parentSessionId: 'fallback-parent',
+          childSessionId: 'fallback-child-session',
+          status: 'error',
+          stopReason: 'max-tokens',
+          lastAssistantMessage: [],
+        },
+      })
+      expect(transport.notifications).toContainEqual({
+        method: 'subagent.finished',
+        params: {
+          provider: 'fork',
+          agentId: 'failed-child-agent',
+          childSessionId: 'failed-child-session',
+          status: 'error',
+          stopReason: 'error',
+        },
+      })
+      expect(transport.notifications.some(n =>
+        n.method === 'subagent.finished'
+        && n.params?.agentId === 'missing-child-agent',
+      )).toBe(false)
+
+      await server.shutdown()
+    } finally {
+      await handle?.dispose()
+      await failedHandle?.dispose()
+      await parentHandle?.dispose()
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('does not re-register an LLM adapter that already exists', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-existing-llm-'))
+    const ctx = await makeHarness(storageDir)
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    await ctx.plugin(LlmDeepSeek, { models: ['preinstalled-model'] })
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport())
+      const inspect = server as unknown as { hasAdapterFor(model: string): boolean }
+
+      expect(inspect.hasAdapterFor('preinstalled-model')).toBe(true)
+      expect(inspect.hasAdapterFor('missing-model')).toBe(false)
+      await server.initialize({ cwd: storageDir, model: 'preinstalled-model' })
+
+      expect(ctx.get('llm')?.models().filter(model => model === 'preinstalled-model')).toEqual(['preinstalled-model'])
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('registers a missing model when an LLM service already exists', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-new-llm-'))
+    const ctx = await makeHarness(storageDir)
+    vi.stubEnv('DEEPSEEK_API_KEY', 'test-key')
+    await ctx.plugin(LlmDeepSeek, { models: ['other-model'] })
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport())
+
+      await server.initialize({ cwd: storageDir, model: 'new-model' })
+
+      expect(ctx.get('llm')?.models()).toEqual(expect.arrayContaining(['other-model', 'new-model']))
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('classifies defensive finish states', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-finish-states-'))
+    const ctx = await makeHarness(storageDir)
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport()) as unknown as {
+        finishedStatus(reason: unknown): 'ok' | 'error'
+        shutdown(): Promise<Record<string, never>>
+      }
+
+      expect(server.finishedStatus(undefined)).toBe('error')
+      expect(server.finishedStatus({ kind: 'max-tokens' })).toBe('error')
+      expect(server.finishedStatus({ kind: 'error' })).toBe('error')
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('reports no adapter when the LLM service is absent', async () => {
+    const ctx = new Context()
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport()) as unknown as {
+        hasAdapterFor(model: string): boolean
+        shutdown(): Promise<Record<string, never>>
+      }
+
+      expect(server.hasAdapterFor('missing-model')).toBe(false)
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+    }
+  })
+
+  it('rejects unknown JSON-RPC runtime methods', async () => {
+    const storageDir = await mkdtemp(join(tmpdir(), 'dsh-jsonrpc-unknown-'))
+    const ctx = await makeHarness(storageDir)
+    try {
+      const server = new HarnessSdkServer(ctx, new FakeTransport())
+
+      await expect(server.handleRequest('does/not/exist', {}))
+        .rejects
+        .toThrow('unknown DeepSeek Harness SDK runtime method: does/not/exist')
+
+      await server.shutdown()
+    } finally {
+      await ctx.fiber.dispose()
+      await rm(storageDir, { recursive: true, force: true })
+    }
+  })
+
+  it('coalesces concurrent session creation and retries a failed creation', async () => {
+    let resolveShared: ((handle: AgentHandle) => void) | undefined
+    const sharedCreation = new Promise<AgentHandle>((resolve) => { resolveShared = resolve })
+    const sharedHandle = { agent: {} as Agent, dispose: vi.fn(() => Promise.resolve()) }
+    const retryHandle = { agent: {} as Agent, dispose: vi.fn(() => Promise.resolve()) }
+    const create = vi.fn<(options: unknown) => Promise<AgentHandle>>()
+      .mockReturnValueOnce(sharedCreation)
+      .mockRejectedValueOnce(new Error('creation failed'))
+      .mockResolvedValueOnce(retryHandle)
+    const ctx = {
+      on: vi.fn(() => () => undefined),
+      agents: { create, get: () => undefined },
+      get: () => undefined,
+    } as unknown as Context
+    const server = new HarnessSdkServer(ctx, new FakeTransport()) as unknown as {
+      getOrCreateSession(sessionId: string): Promise<{ handle: AgentHandle }>
+      shutdown(): Promise<Record<string, never>>
+    }
+
+    const first = server.getOrCreateSession('shared')
+    const second = server.getOrCreateSession('shared')
+    expect(create).toHaveBeenCalledTimes(1)
+    resolveShared?.(sharedHandle)
+    const [firstRecord, secondRecord] = await Promise.all([first, second])
+    expect(firstRecord).toBe(secondRecord)
+
+    await expect(server.getOrCreateSession('retry')).rejects.toThrow('creation failed')
+    await expect(server.getOrCreateSession('retry')).resolves.toMatchObject({ handle: retryHandle })
+    expect(create).toHaveBeenCalledTimes(3)
+
+    await server.shutdown()
+    expect(sharedHandle.dispose).toHaveBeenCalledOnce()
+    expect(retryHandle.dispose).toHaveBeenCalledOnce()
+    await expect(server.getOrCreateSession('after-shutdown')).rejects.toThrow('SDK server is shutting down')
+  })
+
+  it('resolves a relative cwd before creating the session', async () => {
+    const create = vi.fn<(options: unknown) => Promise<AgentHandle>>()
+      .mockResolvedValue({ agent: {} as Agent, dispose: () => Promise.resolve() })
+    const ctx = {
+      on: vi.fn(() => () => undefined),
+      agents: { create, get: () => undefined },
+      get: () => ({ models: () => ['model'] }),
+    } as unknown as Context
+    const server = new HarnessSdkServer(ctx, new FakeTransport()) as unknown as {
+      initialize(params: { cwd: string; model: string }): Promise<unknown>
+      getOrCreateSession(sessionId: string): Promise<unknown>
+      shutdown(): Promise<Record<string, never>>
+    }
+
+    await server.initialize({ cwd: '.', model: 'model' })
+    await server.getOrCreateSession('relative')
+
+    expect(create).toHaveBeenCalledWith(expect.objectContaining({ meta: { cwd: process.cwd() } }))
+    await server.shutdown()
+  })
+
+  it('settles every teardown and aggregates multiple failures', async () => {
+    const firstDispose = vi.fn(() => { throw new Error('first teardown failed') })
+    const secondDispose = vi.fn(() => Promise.reject(new Error('second teardown failed')))
+    const ctx = {
+      on: vi.fn(() => () => undefined),
+      agents: { create: vi.fn(), get: () => undefined },
+      get: () => undefined,
+    } as unknown as Context
+    const server = new HarnessSdkServer(ctx, new FakeTransport()) as unknown as {
+      sessions: Map<string, { handle: AgentHandle; lastTurnEnd: undefined; activePrompt: boolean }>
+      shutdown(): Promise<Record<string, never>>
+    }
+    server.sessions.set('first', { handle: { agent: {} as Agent, dispose: firstDispose }, lastTurnEnd: undefined, activePrompt: false })
+    server.sessions.set('second', { handle: { agent: {} as Agent, dispose: secondDispose }, lastTurnEnd: undefined, activePrompt: false })
+
+    await expect(server.shutdown()).rejects.toThrow('SDK server teardown failed')
+    expect(firstDispose).toHaveBeenCalledOnce()
+    expect(secondDispose).toHaveBeenCalledOnce()
+  })
+
+  it('continues teardown after a subscription disposer fails', async () => {
+    let subscription = 0
+    const listenerFailure = new Error('listener teardown failed')
+    const on = vi.fn(() => {
+      subscription += 1
+      return subscription === 1 ? () => { throw listenerFailure } : () => undefined
+    })
+    const ctx = {
+      on,
+      agents: { create: vi.fn(), get: () => undefined },
+      get: () => undefined,
+    } as unknown as Context
+    const server = new HarnessSdkServer(ctx, new FakeTransport())
+
+    await expect(server.shutdown()).rejects.toBe(listenerFailure)
+    expect(on).toHaveBeenCalledTimes(4)
+  })
+})

packages/ui/jsonrpc/tests/transport.spec.ts

@@ -0,0 +1,260 @@
+import { once } from 'node:events'
+import { PassThrough, Writable } from 'node:stream'
+import { describe, expect, it } from 'vitest'
+import { JsonRpcLineTransport } from '../src/index.ts'
+
+function transportPair() {
+  const aToB = new PassThrough()
+  const bToA = new PassThrough()
+  const a = new JsonRpcLineTransport(bToA, aToB)
+  const b = new JsonRpcLineTransport(aToB, bToA)
+  return { a, b, aToB, bToA }
+}
+
+describe('JsonRpcLineTransport', () => {
+  it('supports bidirectional requests and notifications over newline-delimited JSON-RPC', async () => {
+    const { a, b } = transportPair()
+    const notifications: Record<string, unknown>[] = []
+
+    a.onRequest(async (method, params) => {
+      expect(method).toBe('echo')
+      return { echoed: params }
+    })
+    b.onNotification((method, params) => {
+      notifications.push({ method, params })
+    })
+    a.start()
+    b.start()
+
+    const response = await b.request('echo', { value: 42 })
+    expect(response).toEqual({ echoed: { value: 42 } })
+
+    a.notify('session.finished', { sessionId: 'main', status: 'ok' })
+    a.notify('heartbeat')
+    await new Promise(resolve => setTimeout(resolve, 10))
+    expect(notifications).toEqual([
+      { method: 'session.finished', params: { sessionId: 'main', status: 'ok' } },
+      { method: 'heartbeat', params: {} },
+    ])
+
+    a.close()
+    b.close()
+  })
+
+  it('reports JSON-RPC request errors from the remote peer', async () => {
+    const { a, b } = transportPair()
+    a.onRequest(async () => {
+      throw new Error('handler boom')
+    })
+    a.start()
+    b.start()
+
+    await expect(b.request('explode', {})).rejects.toThrow('handler boom')
+
+    a.close()
+    b.close()
+  })
+
+  it('stringifies non-Error request handler failures', async () => {
+    const { a, b } = transportPair()
+    a.onRequest(async () => {
+      throw 'string boom'
+    })
+    a.start()
+    b.start()
+
+    await expect(b.request('explode-string', {})).rejects.toThrow('string boom')
+
+    a.close()
+    b.close()
+  })
+
+  it('reports method-not-found when no request handler is installed', async () => {
+    const { a, b } = transportPair()
+    a.start()
+    b.start()
+
+    await expect(b.request('missing', {})).rejects.toThrow('method not found: missing')
+
+    a.close()
+    b.close()
+  })
+
+  it('normalizes non-object request params and ignores notifications without a handler', async () => {
+    const { aToB, bToA, b } = transportPair()
+    const seen: Record<string, unknown>[] = []
+    b.onRequest(async (method, params) => {
+      seen.push({ method, params })
+      return { ok: true }
+    })
+    b.start()
+
+    aToB.write('{"jsonrpc":"2.0","method":"ignored"}\n')
+    aToB.write('{"jsonrpc":"2.0","id":7,"method":"array-params","params":[]}\n')
+    const chunk = (await once(bToA, 'data'))[0] as Buffer | string
+
+    expect(seen).toEqual([{ method: 'array-params', params: {} }])
+    expect(JSON.parse(String(chunk))).toEqual({ jsonrpc: '2.0', id: 7, result: { ok: true } })
+    b.close()
+  })
+
+  it('ignores malformed frames and accepts notifications without params', async () => {
+    const { aToB, b } = transportPair()
+    const notifications: Record<string, unknown>[] = []
+    b.onNotification((method, params) => {
+      notifications.push({ method, params })
+    })
+    b.start()
+    b.start()
+
+    aToB.write('not json\n')
+    aToB.write('\n')
+    aToB.write('null\n')
+    aToB.write('{"jsonrpc":"2.0","params":{}}\n')
+    aToB.write('{"jsonrpc":"2.0","method":"tick"}\n')
+    aToB.emit('data', '{"jsonrpc":"2.0","method":"string-chunk"}\n')
+    await new Promise(resolve => setTimeout(resolve, 10))
+
+    expect(notifications).toEqual([
+      { method: 'tick', params: {} },
+      { method: 'string-chunk', params: {} },
+    ])
+    b.close()
+  })
+
+  it('preserves multibyte UTF-8 characters split across Buffer chunks', async () => {
+    const input = new PassThrough()
+    const output = new PassThrough()
+    const transport = new JsonRpcLineTransport(input, output)
+    const notifications: Record<string, unknown>[] = []
+    transport.onNotification((method, params) => { notifications.push({ method, params }) })
+    transport.start()
+
+    const frame = Buffer.from(`${JSON.stringify({ jsonrpc: '2.0', method: 'message', params: { text: '你好' } })}\n`)
+    const character = Buffer.from('你')
+    const characterStart = frame.indexOf(character)
+    expect(characterStart).toBeGreaterThanOrEqual(0)
+    input.write(frame.subarray(0, characterStart + 1))
+    input.write(frame.subarray(characterStart + 1))
+    await new Promise(resolve => setTimeout(resolve, 10))
+
+    expect(notifications).toEqual([{ method: 'message', params: { text: '你好' } }])
+    transport.close()
+  })
+
+  it('flush waits for all earlier output writes', async () => {
+    const events: string[] = []
+    const output = new Writable({
+      write(chunk: Buffer, _encoding, callback) {
+        const label = chunk.length === 0 ? 'barrier' : 'frame'
+        events.push(`start:${label}`)
+        setTimeout(() => {
+          events.push(`finish:${label}`)
+          callback()
+        }, 5)
+      },
+    })
+    const transport = new JsonRpcLineTransport(new PassThrough(), output)
+
+    transport.notify('tick')
+    await transport.flush()
+
+    expect(events).toEqual([
+      'start:frame',
+      'finish:frame',
+      'start:barrier',
+      'finish:barrier',
+    ])
+    transport.close()
+  })
+
+  it('reports an output callback failure from flush', async () => {
+    const output = {
+      write(_chunk: string, callback?: (error?: Error) => void) {
+        callback?.(new Error('flush failed'))
+        return true
+      },
+    }
+    const transport = new JsonRpcLineTransport(new PassThrough(), output as never)
+
+    await expect(transport.flush()).rejects.toThrow('flush failed')
+  })
+
+  it('rejects pending requests when the input closes', async () => {
+    const { aToB, b } = transportPair()
+    b.start()
+
+    const pending = b.request('never-replies', {})
+    aToB.end()
+
+    await expect(pending).rejects.toThrow('JSON-RPC input closed')
+    b.close()
+  })
+
+  it('rejects pending requests when the input errors', async () => {
+    const { aToB, b } = transportPair()
+    b.start()
+
+    const pending = b.request('never-replies', {})
+    aToB.emit('error', new Error('input broke'))
+
+    await expect(pending).rejects.toThrow('input broke')
+    b.close()
+  })
+
+  it('rejects pending requests when the transport closes', async () => {
+    const { b } = transportPair()
+
+    const pending = b.request('never-replies', {})
+    b.close()
+
+    await expect(pending).rejects.toThrow('JSON-RPC transport closed')
+  })
+
+  it('rejects a request when writing the frame throws', async () => {
+    const input = new PassThrough()
+    const output = {
+      write() {
+        throw new Error('write exploded')
+      },
+    }
+    const transport = new JsonRpcLineTransport(input, output as never)
+
+    await expect(transport.request('write-fails', {})).rejects.toThrow('write exploded')
+  })
+
+  it('stringifies non-Error write failures', async () => {
+    const input = new PassThrough()
+    const output = {
+      write() {
+        throw 'write string'
+      },
+    }
+    const transport = new JsonRpcLineTransport(input, output as never)
+
+    await expect(transport.request('write-fails', {})).rejects.toThrow('write string')
+  })
+
+  it('uses a fallback message for malformed JSON-RPC error responses', async () => {
+    const { aToB, bToA, b } = transportPair()
+    b.start()
+
+    const pending = b.request('remote-error', {})
+    const requestChunk = (await once(bToA, 'data'))[0] as Buffer | string
+    const request = JSON.parse(String(requestChunk)) as { id: string }
+    aToB.write(`${JSON.stringify({ jsonrpc: '2.0', id: request.id, error: {} })}\n`)
+
+    await expect(pending).rejects.toThrow('JSON-RPC error')
+    b.close()
+  })
+
+  it('ignores responses that do not match a pending request', async () => {
+    const { aToB, b } = transportPair()
+    b.start()
+
+    aToB.write('{"jsonrpc":"2.0","id":"unknown","result":{"ignored":true}}\n')
+    await new Promise(resolve => setTimeout(resolve, 10))
+
+    b.close()
+  })
+})