Claude Agent SDK (TypeScript) v0.3.317 and v0.3.318

Summary

Two TypeScript Agent SDK releases matching Claude Code 2.1.317 (2026-11-03) and 2.1.318 (2026-11-04). 0.3.317 adds fail-closed hook matchers and one breaking type change; 0.3.318 reports when the stored claude.ai sign-in ends and when a config file is invalid.

Key points

• Install: npm install @anthropic-ai/claude-agent-sdk@0.3.318.
• 0.3.317, onFailure: "block" on hook matchers: a hook callback that throws or returns invalid output blocks the action instead of letting it through, and a warning appears in the stream when a hook fails. Same feature as on_failure="block" in the Python SDK 0.2.177.
• 0.3.317, breaking: the file_unchanged variant of FileReadOutput is gone; a repeated Read returns the file content again. Code that matched that variant needs updating.
• 0.3.317, other: a session_writes_lost system message after the result when a full disk stopped the transcript or ~/.claude.json being saved; lossy in readFile() results when invalid UTF-8 was replaced; task.description in TaskCreate results.
• 0.3.318: credential_expires_at on result messages; config_file_invalid as a startup_failure_reason; the interrupt response now covers a message held behind a model change; PushNotificationInput.status is optional.

Why it matters

Guardrail hooks in SDK apps can now fail closed, and long-running SDK services can alert before a stored sign-in expires.