fix: prevent null output and string render crashes in MessagesBoundary

UserToolSuccessMessage now requires parsedOutput.success before trusting
data, and guards toolResult against non-object values before calling
renderToolResultMessage. String renderedMessage is wrapped in <Text> so
multi-line tool reports (e.g. GoalTool usage report) don't crash Ink.

Defense in depth added to VaultHttpFetchTool/UI (matches the existing
pattern in LocalMemoryRecallTool and GoalTool) and to the
mapToolResultToToolResultBlockParam of both vault/memory tools.

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

bun.lock

@@ -352,6 +352,7 @@
       },
       "devDependencies": {
         "@anthropic-ai/sdk": "^0.81.0",
+        "bun-types": "latest",
       },
     },
   },
@@ -1644,7 +1645,7 @@
 
     "buffer-equal-constant-time": ["buffer-equal-constant-time@1.0.1", "https://registry.npmmirror.com/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz", {}, "sha512-zRpUiDwd/xk6ADqPMATG8vc9VPrkck7T07OIx0gnjmJAnHnTVXNQG3vfvWNuiZIkwu9KrKdA1iJKfsfTVxE6NA=="],
 
-    "bun-types": ["bun-types@1.3.12", "https://registry.npmmirror.com/bun-types/-/bun-types-1.3.12.tgz", { "dependencies": { "@types/node": "*" } }, "sha512-HqOLj5PoFajAQciOMRiIZGNoKxDJSr6qigAttOX40vJuSp6DN/CxWp9s3C1Xwm4oH7ybueITwiaOcWXoYVoRkA=="],
+    "bun-types": ["bun-types@1.3.14", "", { "dependencies": { "@types/node": "*" } }, "sha512-4N0ig0fEomHt5R0KCFWjovxow98rIoRwKolrYdCcknNwMekCXRnWEUvgu5soYV8QXtVsrUD8B95MBOZGPvr6KQ=="],
 
     "bundle-name": ["bundle-name@4.1.0", "https://registry.npmmirror.com/bundle-name/-/bundle-name-4.1.0.tgz", { "dependencies": { "run-applescript": "^7.0.0" } }, "sha512-tjwM5exMg6BGRI+kNmTntNsvdZS1X8BFYS6tnJ2hdH0kVxM6/eVZ2xy+FqStSWvYmtfFMDLIxurorHwDKfDz5Q=="],
 
@@ -3338,6 +3339,8 @@
 
     "@tailwindcss/oxide-wasm32-wasi/tslib": ["tslib@2.8.1", "https://registry.npmmirror.com/tslib/-/tslib-2.8.1.tgz", { "bundled": true }, "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w=="],
 
+    "@types/bun/bun-types": ["bun-types@1.3.12", "https://registry.npmmirror.com/bun-types/-/bun-types-1.3.12.tgz", { "dependencies": { "@types/node": "*" } }, "sha512-HqOLj5PoFajAQciOMRiIZGNoKxDJSr6qigAttOX40vJuSp6DN/CxWp9s3C1Xwm4oH7ybueITwiaOcWXoYVoRkA=="],
+
     "@typespec/ts-http-runtime/https-proxy-agent": ["https-proxy-agent@7.0.6", "https://registry.npmmirror.com/https-proxy-agent/-/https-proxy-agent-7.0.6.tgz", { "dependencies": { "agent-base": "^7.1.2", "debug": "4" } }, "sha512-vK9P5/iUfdl95AI+JVyUuIcVtd4ofvtrOr3HNtM2yxC9bnMbEdp3x01OhQNnjb8IJYi38VlTE3mBXwcfvywuSw=="],
 
     "aggregate-error/indent-string": ["indent-string@4.0.0", "https://registry.npmmirror.com/indent-string/-/indent-string-4.0.0.tgz", {}, "sha512-EdDDZu4A2OyIK7Lr/2zG+w5jmbuk1DVBnEwREQvBzspBJkCEbRa8GxU1lghYcaGJCnRWibjDXlq779X1/y5xwg=="],

package.json

@@ -1,6 +1,6 @@
 {
   "name": "claude-code-best",
-  "version": "2.8.1",
+  "version": "2.8.2",
   "description": "Reverse-engineered Anthropic Claude Code CLI — interactive AI coding assistant in the terminal",
   "type": "module",
   "author": "claude-code-best <claude-code-best@proton.me>",

packages/builtin-tools/src/tools/GoalTool/GoalTool.ts

@@ -137,7 +137,10 @@ export const GoalTool = buildTool({
     return `Updating goal: ${input.status}${input.reason ? ` — ${input.reason}` : ''}`
   },
   renderToolResultMessage(output: Output) {
-    if (output.error) return `Goal error: ${output.error}`
+    if (!output) {
+      return null
+    }
+    if (output?.error) return `Goal error: ${output.error}`
     if (output.report) return output.report
     if (output.goal) {
       return `Goal "${output.goal.objective}" — ${output.goal.status}`

packages/builtin-tools/src/tools/LocalMemoryRecallTool/LocalMemoryRecallTool.ts

@@ -547,7 +547,7 @@ export const LocalMemoryRecallTool = buildTool({
       type: 'tool_result',
       tool_use_id: toolUseID,
       content: jsonStringify(output),
-      is_error: output.error !== undefined,
+      is_error: output?.error !== undefined,
     }
   },
 } satisfies ToolDef<InputSchema, Output>)

packages/builtin-tools/src/tools/VaultHttpFetchTool/UI.tsx

@@ -33,6 +33,9 @@ export function renderToolResultMessage(
   _progressMessagesForMessage: ProgressMessage<ToolProgressData>[],
   { verbose }: { verbose: boolean },
 ): React.ReactNode {
+  // Defense in depth: framework validates via outputSchema, but resumed
+  // transcripts can still produce null here via deserialization edge cases.
+  if (!output) return null;
   if (output.error) {
     return (
       <MessageResponse height={1}>

packages/builtin-tools/src/tools/VaultHttpFetchTool/VaultHttpFetchTool.ts

@@ -409,7 +409,7 @@ export const VaultHttpFetchTool = buildTool({
       type: 'tool_result',
       tool_use_id: toolUseID,
       content: jsonStringify(output),
-      is_error: output.error !== undefined,
+      is_error: output?.error !== undefined,
     }
   },
 } satisfies ToolDef<InputSchema, Output>)

packages/workflow-engine/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 claude-code-best
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/workflow-engine/README.md

@@ -0,0 +1,71 @@
+# @claude-code-best/workflow-engine
+
+Deterministic JS script orchestration engine for multi-agent workflows. The core layer has zero runtime dependencies and talks to the outside world exclusively through **port adapters** — you bring your own agent backend, journal store, and progress sink.
+
+## Why
+
+When you orchestrate multiple LLM agents, you want the orchestration itself to be **deterministic, replayable, and testable**. This engine runs a plain JS script (compiled by Bun's transpiler) with primitives like `agent()`, `phase()`, `parallel()` and `pipeline()`. The non-deterministic parts (the LLM, the file system, the clock) are isolated behind ports, so the same script produces the same journal on every replay.
+
+## Installation
+
+```bash
+bun add @claude-code-best/workflow-engine
+# or
+npm install @claude-code-best/workflow-engine
+```
+
+Runtime peer requirements: `ajv` and `zod` are pulled in automatically as dependencies.
+
+## Minimal example
+
+```ts
+import {
+  createFileJournalStore,
+  createHostHandle,
+  runWorkflow,
+  type WorkflowPorts,
+} from '@claude-code-best/workflow-engine'
+
+const script = `
+export const meta = { name: 'hello', description: 'minimal demo' }
+phase('Greet')
+const reply = await agent({ prompt: 'Say hi in one short sentence.' })
+emit('result', { reply })
+`
+
+const ports: WorkflowPorts = {
+  // Provide your own agent runner + journal + progress emitter.
+  // See examples/smoke.ts for a complete Anthropic SDK wiring.
+} as WorkflowPorts
+
+const handle = createHostHandle()
+await runWorkflow({
+  script,
+  ports,
+  workflowDir: '.wfe/runs/hello',
+  hostHandle: handle,
+})
+```
+
+For a fully wired end-to-end example with the Anthropic SDK, see [`examples/smoke.ts`](./examples/smoke.ts).
+
+## Core primitives
+
+- `agent(params)` — call the configured AgentRunner; supports structured-output via JSON Schema.
+- `phase(name)` — declare a logical phase (display + progress grouping).
+- `parallel([...])` — barrier-style fan-out with bounded concurrency.
+- `pipeline(stream, fn)` — streaming pipeline with per-item hooks.
+- `emit(type, payload)` — emit a progress event to the host.
+- `log.*` / hooks / budgets — see the TypeScript definitions for the full surface.
+
+## Building from source
+
+```bash
+bun install            # from the repo root
+bun run build          # outputs dist/index.js + dist/**/*.d.ts
+bun test               # 178 tests
+```
+
+## License
+
+MIT © claude-code-best

packages/workflow-engine/package.json

@@ -1,19 +1,69 @@
 {
   "name": "@claude-code-best/workflow-engine",
   "version": "0.1.0",
-  "private": true,
+  "description": "Deterministic JS script orchestration engine for multi-agent workflows. Zero core-layer runtime dependencies; talks to the world via port adapters.",
   "type": "module",
-  "main": "./src/index.ts",
+  "license": "MIT",
-  "types": "./src/index.ts",
+  "author": "claude-code-best <claude-code-best@proton.me>",
+  "homepage": "https://github.com/claude-code-best/claude-code/tree/main/packages/workflow-engine#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/claude-code-best/claude-code.git",
+    "directory": "packages/workflow-engine"
+  },
+  "bugs": {
+    "url": "https://github.com/claude-code-best/claude-code/issues"
+  },
+  "keywords": [
+    "workflow",
+    "orchestration",
+    "multi-agent",
+    "claude",
+    "automation",
+    "scripting",
+    "deterministic"
+  ],
+  "main": "./dist/index.js",
+  "module": "./dist/index.js",
+  "types": "./dist/index.d.ts",
   "exports": {
-    ".": "./src/index.ts",
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js",
+      "default": "./dist/index.js"
+    },
     "./package.json": "./package.json"
   },
+  "files": [
+    "dist",
+    "src",
+    "!src/**/__tests__",
+    "!src/**/*.test.ts",
+    "scripts/build.ts",
+    "tsconfig.json",
+    "tsconfig.build.json",
+    "README.md",
+    "LICENSE"
+  ],
+  "sideEffects": false,
+  "engines": {
+    "node": ">=20"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
   "dependencies": {
     "ajv": "^8.18.0",
     "zod": "^4.3.6"
   },
   "devDependencies": {
-    "@anthropic-ai/sdk": "^0.81.0"
+    "@anthropic-ai/sdk": "^0.81.0",
+    "bun-types": "latest"
+  },
+  "scripts": {
+    "build": "bun run scripts/build.ts",
+    "typecheck": "tsc --noEmit",
+    "test": "bun test",
+    "prepublishOnly": "bun run test && bun run build"
   }
 }

packages/workflow-engine/scripts/build.ts

@@ -0,0 +1,21 @@
+import { mkdir, rm } from 'node:fs/promises'
+
+const ROOT = new URL('../', import.meta.url)
+const DIST = new URL('../dist/', import.meta.url)
+
+await rm(DIST, { recursive: true, force: true })
+await mkdir(DIST, { recursive: true })
+
+// Emit dist/**/*.js + dist/**/*.d.ts (+ maps) via tsc.
+const proc = Bun.spawn(['bunx', 'tsc', '-p', 'tsconfig.build.json'], {
+  cwd: ROOT.pathname,
+  stdout: 'inherit',
+  stderr: 'inherit',
+})
+const exitCode = await proc.exited
+if (exitCode !== 0) {
+  console.error('tsc emit failed')
+  process.exit(exitCode)
+}
+
+console.log('✓ build complete')

packages/workflow-engine/src/index.ts

@@ -16,10 +16,16 @@ export * from './engine/context.js'
 export * from './engine/hooks.js'
 export * from './engine/runWorkflow.js'
 export * from './progress/events.js'
-export {
+import {
   createWorkflowTool,
   type WorkflowToolDescriptor,
 } from './tool/WorkflowTool.js'
-export { workflowInputSchema, type WorkflowInput } from './tool/schema.js'
+import { workflowInputSchema, type WorkflowInput } from './tool/schema.js'
-export { persistInlineScript } from './tool/persistInline.js'
+import { persistInlineScript } from './tool/persistInline.js'
-export { WORKFLOW_TOOL_NAME } from './tool/constants.js'
+export {
+  createWorkflowTool,
+  type WorkflowToolDescriptor,
+  workflowInputSchema,
+  type WorkflowInput,
+  persistInlineScript,
+}

packages/workflow-engine/tsconfig.build.json

@@ -0,0 +1,21 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "noEmit": false,
+    "declaration": true,
+    "declarationMap": false,
+    "sourceMap": false,
+    "outDir": "dist",
+    "rootDir": "src",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "target": "ESNext"
+  },
+  "include": ["src/**/*"],
+  "exclude": [
+    "node_modules",
+    "src/**/__tests__/**",
+    "examples/**",
+    "scripts/**"
+  ]
+}

src/components/messages/UserToolResultMessage/UserToolSuccessMessage.tsx

@@ -67,7 +67,14 @@ export function UserToolSuccessMessage({
   if (parsedOutput && !parsedOutput.success) {
     return null;
   }
-  const toolResult = parsedOutput?.data ?? message.toolUseResult;
+  // Only trust schema-validated output. Fall back to raw toolUseResult only
+  // when it's a non-null object — schemas without outputSchema, or successful
+  // parses that yield null/undefined data, must not reach renderToolResultMessage
+  // (tool UIs access output.error / output.action on first line and crash).
+  const toolResult = parsedOutput?.success ? parsedOutput.data : message.toolUseResult;
+  if (!toolResult || typeof toolResult !== 'object') {
+    return null;
+  }
 
   // Collapse diff display for old messages (verbose/ctrl+o overrides)
   const effectiveStyle = shouldCollapseDiffs && !verbose ? 'condensed' : style;
@@ -88,6 +95,11 @@ export function UserToolSuccessMessage({
     return null;
   }
 
+  // Ink requires text strings to be inside <Text>. Tools that return plain
+  // multi-line strings (e.g. GoalTool's usage report) crash without the wrap.
+  // React elements from UI.tsx files pass through unchanged.
+  const wrappedMessage = typeof renderedMessage === 'string' ? <Text>{renderedMessage}</Text> : renderedMessage;
+
   // Tools that return '' from userFacingName opt out of tool chrome and
   // render like plain assistant text. Skip the tool-result width constraint
   // so MarkdownTable's SAFETY_MARGIN=4 (tuned for the assistant-text 2-col
@@ -97,7 +109,7 @@ export function UserToolSuccessMessage({
   return (
     <Box flexDirection="column">
       <Box flexDirection="column" width={rendersAsAssistantText ? undefined : width}>
-        {renderedMessage}
+        {wrappedMessage}
         {feature('BASH_CLASSIFIER')
           ? classifierRule && (
               <MessageResponse height={1}>

src/services/acp/bridge/paths.ts

@@ -1,5 +1,12 @@
 // Pure path-normalisation helper used by toolInfo / toolResults / forwarding.
-import { isAbsolute, resolve } from 'node:path'
+//
+// POSIX semantics are used so that emitted paths are platform-independent:
+// ACP v1 spec (tool-calls.mdx:304-306) requires ToolCallLocation.path /
+// Diff.path to be absolute, and the wire format is POSIX-style regardless of
+// the host OS. Using the platform-specific `node:path` here would prepend the
+// Windows drive letter (e.g. "D:\...") to POSIX-style inputs like
+// "/Users/test/project" — silently corrupting paths emitted to ACP clients.
+import { isAbsolute, resolve } from 'node:path/posix'
 
 /**
  * Normalises an emitted file path against the session cwd so that

src/services/acp/utils.ts

@@ -172,7 +172,9 @@ export function sanitizeTitle(text: string): string {
 
 // ── Path display helpers ──────────────────────────────────────────
 
-import * as path from 'node:path'
+// POSIX semantics so paths are normalised consistently regardless of host OS.
+// ACP paths are always POSIX-style (see bridge/paths.ts for the same rationale).
+import * as path from 'node:path/posix'
 
 /**
  * Convert an absolute file path to a project-relative path for display.
@@ -186,7 +188,7 @@ export function toDisplayPath(filePath: string, cwd?: string): string {
     resolvedFile.startsWith(resolvedCwd + path.sep) ||
     resolvedFile === resolvedCwd
   ) {
-    return path.relative(resolvedCwd, resolvedFile).replaceAll('\\', '/')
+    return path.relative(resolvedCwd, resolvedFile)
   }
   return filePath
 }

src/setup.ts

@@ -94,10 +94,20 @@ export async function setup(
     // (SessionStart in particular) can spawn and snapshot process.env.
     if (feature('UDS_INBOX')) {
       const m = await import('./utils/udsMessaging.js')
-      await m.startUdsMessaging(
+      try {
-        messagingSocketPath ?? m.getDefaultUdsSocketPath(),
+        await m.startUdsMessaging(
-        { isExplicit: messagingSocketPath !== undefined },
+          messagingSocketPath ?? m.getDefaultUdsSocketPath(),
-      )
+          { isExplicit: messagingSocketPath !== undefined },
+        )
+      } catch (error) {
+        logError(error)
+        console.error(
+          chalk.red(
+            `Error: Failed to start messaging socket (UDS_INBOX): ${errorMessage(error)}`,
+          ),
+        )
+        process.exit(1)
+      }
     }
   }
 

src/utils/__tests__/udsMessaging.test.ts

@@ -21,6 +21,8 @@ import {
   MAX_UDS_INBOX_BYTES,
   MAX_UDS_FRAME_BYTES,
   MAX_UDS_CLIENTS,
+  MAX_UNIX_SOCKET_PATH_LENGTH,
+  assertValidUnixSocketPath,
   formatUdsAddress,
   parseUdsTarget,
   sendUdsMessage,
@@ -34,11 +36,23 @@ let previousConfigDir: string | undefined
 let tempConfigDir = ''
 
 function socketPath(label: string): string {
-  const suffix = `${process.pid}-${Date.now()}-${Math.random().toString(16).slice(2)}-${label}`
+  const suffix = `${process.pid}-${Math.random().toString(16).slice(2)}-${label}`
   if (process.platform === 'win32') {
     return `\\\\.\\pipe\\claude-code-test-${suffix}`
   }
-  return join(tmpdir(), 'claude-code-test', `${suffix}.sock`)
+  const base =
+    process.platform === 'darwin'
+      ? '/tmp/claude-uds-test'
+      : join(tmpdir(), 'cc-uds-test')
+  return join(base, `${suffix}.sock`)
+}
+
+function shortTestDir(prefix: string): string {
+  const id = `${process.pid}-${Math.random().toString(16).slice(2)}`
+  if (process.platform === 'darwin') {
+    return join('/tmp', `${prefix}-${id}`)
+  }
+  return join(tmpdir(), `${prefix}-${id}`)
 }
 
 function sleep(ms: number): Promise<void> {
@@ -499,6 +513,27 @@ describe('UDS inbox retention', () => {
     expect(getDefaultUdsSocketPath()).not.toBe(firstPath)
   })
 
+  test('default socket path stays within AF_UNIX length limit', () => {
+    const path = getDefaultUdsSocketPath()
+    if (process.platform === 'win32') return
+    expect(Buffer.byteLength(path, 'utf8')).toBeLessThanOrEqual(
+      MAX_UNIX_SOCKET_PATH_LENGTH,
+    )
+    expect(() => assertValidUnixSocketPath(path)).not.toThrow()
+  })
+
+  test('rejects socket paths longer than AF_UNIX limit', () => {
+    if (process.platform === 'win32') return
+    const longPath = `/tmp/${'x'.repeat(MAX_UNIX_SOCKET_PATH_LENGTH)}.sock`
+    expect(() => assertValidUnixSocketPath(longPath)).toThrow(/max 104/)
+  })
+
+  test('default socket path can bind on Node.js', async () => {
+    const path = getDefaultUdsSocketPath()
+    await startUdsMessaging(path, { isExplicit: true })
+    await stopUdsMessaging()
+  })
+
   test('rejects oversized receiver responses before retaining them', async () => {
     const path = socketPath('oversized-response')
     if (process.platform !== 'win32') {
@@ -688,10 +723,7 @@ describe('UDS inbox retention', () => {
     })
 
     test('fails closed when an explicit socket parent is not private', async () => {
-      const parent = join(
+      const parent = shortTestDir('uds-sp')
-        tmpdir(),
-        `uds-socket-parent-${process.pid}-${Date.now()}-${Math.random().toString(16).slice(2)}`,
-      )
       await mkdir(parent, { recursive: true, mode: 0o755 })
       await chmod(parent, 0o755)
 
@@ -707,10 +739,7 @@ describe('UDS inbox retention', () => {
     })
 
     test('fails closed when an explicit socket parent is a file', async () => {
-      const parentFile = join(
+      const parentFile = shortTestDir('uds-spf')
-        tmpdir(),
-        `uds-socket-parent-file-${process.pid}-${Date.now()}-${Math.random().toString(16).slice(2)}`,
-      )
       await writeFile(parentFile, 'not a directory', 'utf-8')
 
       try {

src/utils/messages.ts

@@ -753,6 +753,7 @@ export function normalizeMessages(messages: Message[]): NormalizedMessage[] {
   // and remains true for all subsequent messages in the normalization process.
   let isNewChain = false
   return messages.flatMap(message => {
+    if (!message) return []
     switch (message.type) {
       case 'assistant': {
         const aMsg = message as AssistantMessage
@@ -776,7 +777,7 @@ export function normalizeMessages(messages: Message[]): NormalizedMessage[] {
             isVirtual: message.isVirtual,
             requestId: message.requestId,
             uuid,
-            error: message.error,
+            error: message?.error,
             isApiErrorMessage: message.isApiErrorMessage,
             advisorModel: message.advisorModel,
           } as NormalizedAssistantMessage
@@ -2376,6 +2377,7 @@ export function normalizeMessagesForAPI(
       },
     )
     .forEach(message => {
+      if (!message) return []
       switch (message.type) {
         case 'system': {
           // local_command system messages need to be included as user messages

src/utils/messages/mappers.ts

@@ -29,6 +29,7 @@ export function toInternalMessages(
   messages: readonly DeepImmutable<SDKMessage>[],
 ): Message[] {
   return messages.flatMap(message => {
+    if (!message) return []
     switch (message.type) {
       case 'assistant':
         return [
@@ -127,6 +128,7 @@ export function fromSDKCompactMetadata(
 
 export function toSDKMessages(messages: Message[]): SDKMessage[] {
   return messages.flatMap((message): SDKMessage[] => {
+    if (!message) return []
     switch (message.type) {
       case 'assistant':
         return [
@@ -138,7 +140,7 @@ export function toSDKMessages(messages: Message[]): SDKMessage[] {
             session_id: getSessionId(),
             parent_tool_use_id: null,
             uuid: message.uuid,
-            error: message.error,
+            error: message?.error,
           },
         ]
       case 'user':

src/utils/udsMessaging.ts

@@ -85,13 +85,26 @@ export const MAX_UDS_CLIENTS = 128
 export const UDS_AUTH_TIMEOUT_MS = 2_000
 export const UDS_IDLE_TIMEOUT_MS = 30_000
 
+/** macOS/BSD AF_UNIX `sun_path` limit (bytes, excluding NUL). */
+export const MAX_UNIX_SOCKET_PATH_LENGTH = 104
+
 // ---------------------------------------------------------------------------
 // Public API — socket path helpers
 // ---------------------------------------------------------------------------
 
+export function assertValidUnixSocketPath(path: string): void {
+  if (process.platform === 'win32') return
+  const byteLength = Buffer.byteLength(path, 'utf8')
+  if (byteLength > MAX_UNIX_SOCKET_PATH_LENGTH) {
+    throw new Error(
+      `[udsMessaging] socket path is ${byteLength} bytes (max ${MAX_UNIX_SOCKET_PATH_LENGTH}): ${path}`,
+    )
+  }
+}
+
 /**
- * Default socket path based on PID, placed in a tmpdir subdirectory so it
+ * Default socket path based on PID. Uses a flat file under a short temp
- * survives across config-home changes and avoids polluting ~/.claude.
+ * directory so the path stays within the AF_UNIX limit on macOS.
  *
  * On Windows, Node.js requires named pipe paths in the `\\.\pipe\` namespace;
  * file-system paths like `C:\...\Temp\x.sock` cause EACCES. Bun handles both
@@ -99,17 +112,19 @@ export const UDS_IDLE_TIMEOUT_MS = 30_000
  */
 export function getDefaultUdsSocketPath(): string {
   if (defaultSocketPath) return defaultSocketPath
-  const nonce = randomBytes(16).toString('hex')
+  const nonce = randomBytes(8).toString('hex')
   if (process.platform === 'win32') {
     defaultSocketPath = `\\\\.\\pipe\\claude-code-${process.pid}-${nonce}`
     return defaultSocketPath
   }
+
   defaultSocketPath = join(
     tmpdir(),
-    'claude-code-socks',
+    'cc-socks',
     `${process.pid}-${nonce}`,
     'messaging.sock',
   )
+  assertValidUnixSocketPath(defaultSocketPath)
   return defaultSocketPath
 }
 
@@ -416,6 +431,8 @@ export async function startUdsMessaging(
     return
   }
 
+  assertValidUnixSocketPath(path)
+
   // Ensure parent directory exists (skip on Windows — pipe paths aren't files)
   if (process.platform !== 'win32') {
     await ensureSocketParent(path)