# Claude Code v2.1.21 > Claude Code v2.1.21, released 28 Jan 2026 (2026-01-28). 13 entries read out of the shipped bundle. Unofficial, and not affiliated with Anthropic. Web version: https://changelogs.core-directive.com/v/2.1.21 This release adds enterprise organization policy controls, improves the hook system for better SDK integration, and enhances shell completion support with automatic cache generation. The update also refines user-facing messages and adds experimental tool search optimization. ## Changes ### Organization Policy Limits (Enterprise) **What** Enterprise organizations can now enforce access policies that restrict certain Claude Code features like remote sessions. **Details** - New API endpoint `/api/claude_code/policy_limits` fetches organization-defined restrictions - Policies are cached locally at `~/.config/claude-code/policy-limits.json` - Automatic refresh on authentication changes and periodic background polling - Currently enforces `allow_remote_sessions` policy for teleport and remote session creation - Only available for enterprise subscription users with proper API scopes - When blocked, users see: "Remote sessions are disabled by your organization's policy." **Evidence** `BB()` at line 388033 (enterprise check, uses `subscriptionType !== "enterprise"`), `YP()` at line 380468 (policy checker, uses `"allow_remote_sessions"`), `IX2()` at line 380287 (API endpoint builder, contains `"/api/claude_code/policy_limits"`) ### Shell Completion Cache Management **What** Shell completion files are now automatically generated and cached, with auto-regeneration on updates. **Usage** Completion files are stored at: - `~/.claude/completion.bash` for bash - `~/.claude/completion.zsh` for zsh - `~/.claude/completion.fish` for fish (stored in `$XDG_CONFIG_HOME/fish/config.fish`) **Details** - Completion caches are automatically regenerated after Claude Code updates - Uses `claude completion --output ` under the hood - Logs show `update: Regenerating completion cache` and `update: Regenerated completion cache at ` - Improves shell startup performance by avoiding regenerating completions on every shell launch **Evidence** `k69()` at line 184272-184299 (shell detection, contains `"completion.bash"`, `"completion.fish"`, `"completion.zsh"`), `wq6()` at line 184307 (cache regeneration, contains `"update: Regenerating"` and `"completion cache"`) ### Enhanced Hook System for SDK Integration **What** The compacting system now uses structured progress callbacks instead of text spinner messages, enabling better programmatic integration. **Details** - New `onCompactProgress` callback with `{ type, hookType }` events - Hook types include `"pre_compact"` and `"session_start"` - Event types: `"hooks_start"` when hooks begin execution - Replaces legacy `setSpinnerMessage` calls with structured events - UI still displays "Running PreCompact hooks…" and "Running SessionStart hooks…" but via event-driven rendering **Evidence** Line 449199 (hook start event, `K.onCompactProgress?.({ type: "hooks_start", hookType: "pre_compact" })`), line 449280 (session start event, `hookType: "session_start"`), line 571772 (UI rendering, contains `"Running PreCompact hooks…"`) ### Task List ID Ordering **What** Task list documentation now recommends working on tasks in ID order (lowest first) when multiple tasks are available. **Details** - New `.highwatermark` file for tracking task ID generation - Documentation updated to say "Prefer working on tasks in ID order (lowest ID first)" - Helps teams coordinate work more predictably - Part of the teammate workflow system **Evidence** `Co3 = ".highwatermark"` at line 155744 (highwatermark constant), string literal `"Prefer working on tasks in ID order"` in TaskList tool description ### Personalized Welcome Message **What** The startup welcome message now shows which IDE or terminal you're using. **Details** - Format changed from "Welcome to Claude Code" to "Welcome to Claude Code for " - Shows editor name like "VS Code", "Cursor", "Zed", or terminal name - Detected from IDE integration context or `$TERM` environment variable - Makes multi-IDE workflows clearer **Evidence** Line 306414 (welcome message rendering, `"Welcome to Claude Code for ", $` where `$` is IDE name from `J0()`) ### Clearer Thinking Mode Warning The warning when changing thinking mode mid-conversation is now more explicit about performance impacts. **Old message**: "Changing mid-conversation may reduce quality. For best results, set this at the start of a session." **New message**: "Changing thinking mode mid-conversation will increase latency and may reduce quality. For best results, set this at the start of a session." The message now mentions latency impact explicitly, helping users make informed decisions. **Evidence** Line 472714 (settings UI), line 559581 (toggle confirmation dialog), contains `"Changing thinking mode mid-conversation will increase latency and may reduce quality"` ### Simplified Auto Tool Search Logging Debug log messages for automatic tool search are now clearer and more concise. **Changes**: - When enabled: "Auto tool search enabled: " (no more enabled/disabled toggle noise) - When disabled: "Auto tool search disabled: " - Removed redundant "threshold" and "percentage" details from enable/disable messages - Threshold context still present but only for character fallback edge cases **Evidence** Line 451497 (enabled message, `"Auto tool search enabled: ${X}"`), line 451529 (disabled message, `"Auto tool search disabled: ${X}"`) ### Improved Marketplace Installation for Headless Mode Plugin installation in headless/SDK mode now supports extra marketplaces and has better error reporting. **Details** - Now installs plugins from all configured marketplaces, not just default - Skips plugins from unknown marketplaces with clear logging - Individual marketplace installation failures don't block other installations - Logs: `installPluginsForHeadless: installed extra marketplace ` on success - Logs: `installPluginsForHeadless: failed to install extra marketplace ` on failure - Logs: `installPluginsForHeadless: skipping N plugins from unknown marketplaces: ` **Evidence** Lines 580240-580263 (marketplace installation loop, contains `"installPluginsForHeadless: installed extra marketplace"` and `"skipping ${J.length} plugins from unknown marketplaces"`) ### Enhanced PermissionRequest Hook Error Messages When a PermissionRequest hook denies an action, the error message now defaults to a clearer system message if the hook doesn't provide one. **Details** - Default message: "Permission denied by PermissionRequest hook" - Helps debug which hook is blocking an operation - Part of the plugin hook system for security controls **Evidence** Line 579288 (hook denial, `X.message || "Permission denied by PermissionRequest hook"`) ### CLI Init Only Flag Description Update The `--init-only` flag description now accurately reflects that it runs both Setup and SessionStart:startup hooks, not just Setup. **Old**: "Run Setup hooks with init trigger, then exit" **New**: "Run Setup and SessionStart:startup hooks, then exit" **Evidence** Line 585008 (CLI option description, contains `"Run Setup and SessionStart:startup hooks, then exit"`) ### Deferred Tool Search Experiment (tengu_tst_kx7) An A/B test is running to evaluate enabling automatic tool search even when below the token threshold, if deferred tools are present in the context. **Details** - Feature flag: `tengu_tst_kx7` (controlled by GrowthBook) - Activates when: below normal tool search threshold BUT deferred tools exist - Hypothesis: Deferred tools signal potential tool use even at low token counts - Logs: `"Tool search enabled via experiment (tengu_tst_kx7)"` or `"disabled via experiment"` - Falls back silently if GrowthBook not ready: `"tengu_tst_kx7: GrowthBook not ready, skipping"` **Evidence** Line 451507 (experiment check, contains `V4("tengu_tst_kx7", !1)` and `"via experiment (tengu_tst_kx7): below threshold, deferred tools present"`) ## Bug Fixes - Fixed stream completion fallback trigger when message_start received but no content blocks completed (`"Stream completed with message_start but no content blocks completed - triggering non-streaming fallback"`) - Fixed agent logging to properly identify agent in compact messages (`"[inProcessRunner] ${K.agentId} compacting history"` now includes agent ID) ## Notes **For SDK users**: The `onCompactProgress` callback replaces `setSpinnerMessage` for hook events. Update your integration to handle the new structured events: `{ type: "hooks_start", hookType: "pre_compact" | "session_start" }` **For enterprise users**: If remote sessions stop working, check with your organization admin about the new `allow_remote_sessions` policy. This is controlled at the organization level via the policy limits API.