Claude Code v2.1.129: Autonomous Loop Persistence Guidance and Background Agent State Classifier

Claude Code v2.1.129 (released as CC v2.1.129) introduces a new system prompt for autonomous loop persistence and removes the adversarial verification specialist subagent. The release also significantly expands the background agent state classifier prompt with detailed guidance on state boundaries, marker rules, and cron/re-poll handling.

New: Autonomous Loop Persistence Guidance

A new system prompt, CLAUDE_CODE_LOOP_PERSISTENT, provides timer-invocation guidance for autonomous work loops. Key instructions include:

• When to continue established work rather than starting fresh
• How to maintain current pull requests across invocations
• When to broaden scope before stopping (e.g., if a task is nearly complete but blocked, broaden to other tasks)
• Requiring clear authorization before performing irreversible actions (e.g., destructive file operations, irreversible API calls)

This prompt is designed to make autonomous agent loops more persistent and context-aware across timer-triggered invocations.

Removed: Verification Specialist Subagent

The adversarial verification subagent prompt has been removed entirely. This subagent previously required independent builds, tests, browser/API checks, and returning PASS/FAIL/PARTIAL verdicts without modifying the project. Its removal suggests the development team is shifting away from explicit adversarial verification in favor of the new loop persistence and state classification approaches.

Removed: Background Agent State Classification Examples

A standalone prompt containing background-agent state-classification examples has also been removed. These examples have likely been integrated into the expanded background agent state classifier prompt (see below).

Expanded: Background Agent State Classifier

The background agent state classifier prompt has been substantially expanded with:

• Detailed boundaries between done, working, blocked, and failed states
• Explicit marker rules for state transitions
• Embedded examples for each state
• Handling of cron-triggered and re-poll invocations
• Distinctions between optional-offer vs delivery-gate notifications
• Lock-screen-oriented detail, needs, and output.result guidance

Who It's For

Developers using Claude Code in autonomous/background agent loops who need fine-grained control over task persistence, state classification, and notification behavior.