Claude Code v2.0.54

What: New policy setting that restricts hook execution to only those defined in managed enterprise settings, blocking user, project, local, and plugin hooks.

How to use: Configure in your managed policy settings:

{
  "policySettings": {
    "allowManagedHooksOnly": true,
    "hooks": {
      "PreToolUse": [...]
    }
  }
}

Details:

• When enabled, only hooks from policySettings.hooks will execute
• Plugin hooks are explicitly skipped with log message "Skipping plugin hooks - allowManagedHooksOnly is enabled"
• Complements existing disableAllHooks setting by providing a middle ground
• Evidence: eQ1() at line 337237, VA0() at line 337232, policy schema at line 503153

What: Probabilistic sampling mechanism that reduces telemetry overhead by logging only a configurable fraction of events.

Details:

• Sampling rates configured via Statsig dynamic config tengu_event_sampling_config
• Per-event sample rates between 0 and 1 (0% to 100%)
• When sampled, events include sample_rate metadata for statistical reconstruction
• Events with sample_rate: 0 are completely dropped
• Evidence: lg1() at line 231903, ZD6() at line 231900, modified ZA() at line 507257

What: Parallel download attempts from new CDN infrastructure (downloads.claude.ai) alongside the primary Google Cloud Storage source, for performance testing without user impact.

Details:

• Runs silently in background during binary downloads
• Collects latency, success/failure, and error type metrics
• Reports via tengu_native_cdn_dark_read_failure telemetry event
• Creates temporary claude-cdn-dark-read-* directories, automatically cleaned up
• Evidence: kp5() at line 428907, Ah2 CDN URL at line 428959

What: New warning when MCP endpoint files cannot be found, with automatic fallback to state files.

How it appears:

Warning: MCP endpoint file not found at <path> (session: <id>). Falling back to state file.

Details:

• Warning displays once per session (uses lV9 flag to prevent spam)
• Error messages now include session IDs and file paths for easier debugging
• Evidence: DH() at line 519760, warning message at line 519769

What: OSC 9;4 taskbar progress sequences now only emit for terminals that properly support them.

Details:

• Enabled for: ConEmu (via ConEmuANSI/ConEmuPID/ConEmuTask env vars) and Ghostty (TERM=xterm-ghostty)
• Disabled for: Windows Terminal (WT_SESSION) and non-TTY environments
• Prevents garbled output in unsupported terminals
• Evidence: New GQ6() function at line 220728, conditional rendering at line 220776

What: Session memory now uses project-based paths instead of global paths, with centralized helper functions.

Details:

• New path: <project-dir>/<session-id>/session-memory/ instead of <global-config>/session-memory/
• Three new helpers: zI1() (base path), _B1() (summary.md path), zP3() (path check)
• New summary.md file with structured template (Task specification, Files and Functions, Workflow, etc.)
• Better isolation between projects and sessions
• Evidence: zI1() at line 506034, _B1() at line 506037, jG2() summary reader at line 340819

What: Plan injection/stripping moved from inline code to dedicated helper functions for cleaner architecture.

Details:

• O_2() at line 403698: Adds plan content to ExitPlanMode tool input
• R_2() at line 403754: Strips plan field from tool outputs in conversation history
• Improves code maintainability and separation of concerns
• Evidence: See lines referenced above, formerly inline at v2.0.53:404788-404791

What: Successful binary downloads now report latency metrics.

Details:

• New tengu_binary_download_success event with latency_ms and is_cdn fields
• Helps track download performance across different sources
• Evidence: Bh2() at line 428934, telemetry call at line 428563

What: Internal testing tool for generating large outputs has been removed from the codebase.

Details:

• Tool was only available when ENABLE_OVERFLOW_TEST_TOOL environment variable was set
• Used for testing tool result persistence with configurable output sizes (1-10000 KB)
• Some orphaned schema definitions remain as dead code (BdZ, GdZ at line 475943)
• Evidence: Full removal from v2.0.53 lines 475722-475818

• Various import statements reorganized and consolidated
• No functional impact on users
• Evidence: Multiple import changes in diff (stream, child_process, crypto, fs, path modules)

• ZA0 → DA0, YLA → XLA for hook initialization
• Now use centralized VA0() to get hooks respecting allowManagedHooksOnly
• Evidence: Lines 337259-337268 in v2.0.54