Claude docs changes for January 31st, 2026 [diff]

Executive Summary

• New version 2.1.27: Added --from-pr flag to resume sessions linked to GitHub PRs with automatic PR linking
• Hooks system received a complete documentation rewrite with new prompt-based and agent-based hook types
• New MCP servers added: Google BigQuery, LILT, Make, Wyndham Hotels

New Claude Code versions

2.1.27

New features

• Added --from-pr flag to resume sessions linked to a specific GitHub PR number or URL
• Sessions are now automatically linked to PRs when created via gh pr create

Existing feature improvements

• Added tool call failures and denials to debug logs
• Windows: Improved bash command execution for users with .bashrc files
• Windows: Reduced console windows flashing when spawning child processes

Major bug fixes

• Fixed context management validation error for gateway users, ensuring CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1 avoids the error
• Fixed /context command not displaying colored output
• Fixed status bar duplicating background task indicator when PR status was shown
• VSCode: Fixed OAuth token expiration causing 401 errors after extended sessions

Claude Code changes

Changed documents

Analytics [Source]

• Added clarification that contribution metrics only cover users within your claude.ai organization. Usage through the Claude Console API or third-party integrations is not included. [line 22] [Source]
• Added disclaimer that metrics are deliberately conservative and represent an underestimate of Claude Code's actual impact. [line 60] [Source]

CLI reference [Source]

• Added new --from-pr flag to resume sessions linked to a specific GitHub PR. Accepts a PR number or URL. Sessions are automatically linked when created via gh pr create. [line 37] [Source]

Common workflows [Source]

• Added documentation for automatic PR session linking: when you create a PR using gh pr create, the session is automatically linked to that PR and can be resumed later with claude --from-pr <number>. [line 520] [Source]
• Added claude --from-pr 123 as a new option for resuming sessions linked to a specific pull request. [line 780] [Source]

Features overview [Source]

• Expanded hooks description to clarify they fire at specific lifecycle events like tool execution, session boundaries, prompt submission, permission requests, and compaction. [line 151] [Source]
• Updated hooks link title from "Run scripts on Claude Code events" to "Automate workflows with hooks" and changed target to hooks-guide.md. [line 169] [Source]

Headless [Source]

• Added new section on streaming responses with --output-format stream-json, --verbose, and --include-partial-messages flags. [lines 89-112] [Source]
• Included example of using jq to filter for text deltas and display streaming text. [lines 89-112] [Source]

Hooks guide [Source]

• Complete page restructure: Changed title from "Get started with Claude Code hooks" to "Automate workflows with hooks"
• Added new introduction explaining that hooks can be prompt-based or agent-based, not just shell commands
• Added new walkthrough section with step-by-step first hook setup
• Reorganized examples into common patterns: notifications, auto-formatting, protected file blocking, and context re-injection
• Added new "How hooks work" section explaining event firing and hook types
• Added new sections on hook input/output, matchers, and configuration locations
• Added documentation for prompt-based hooks and agent-based hooks
• Added new troubleshooting section with common issues and solutions

Hooks [Source]

• Complete page rewrite repositioned as reference documentation instead of getting started guide
• Added new "How a hook resolves" section with detailed flow diagram explanation
• Expanded configuration section with three-level nesting explanation (event → matcher → handler)
• Added new matcher patterns section with comprehensive table of event-specific matchers
• Added new hook handler fields section documenting command, prompt, and agent hook types
• Added new sections for: Match MCP tools, Reference scripts by path, Hook input and output with JSON schemas, Exit code output behavior
• Removed Setup event from the hook lifecycle
• Added Notification event to hook lifecycle table

Interactive mode [Source]

• Added "Purple: merged" to the PR status indicator colors. [line 274] [Source]

MCP [Source]

• Removed Granola MCP server from the list
• Added Google Cloud BigQuery MCP server with add command
• Added LILT MCP server with add command
• Added Make MCP server with add command
• Added Wyndham Hotels and Resorts MCP server with add command

Plugins [Source]

• Updated hook example to show hooks receive JSON on stdin: changed from "command": "npm run lint:fix $FILE" to using jq to extract file path from JSON input: "command": "jq -r '.tool_input.file_path' | xargs npm run lint:fix". [line 428] [Source]

Plugins reference [Source]

• Removed Setup event from the list of supported hook events in plugins. [line 117] [Source]

Settings [Source]

• Added new network.allowAllUnixSockets setting: "Allow all Unix socket connections in sandbox. Default: false". [line 259] [Source]
• Added new network.allowedDomains setting: "Array of domains to allow for outbound network traffic. Supports wildcards (e.g., *.example.com)". [line 261] [Source]
• Clarified ANTHROPIC_CUSTOM_HEADERS environment variable: added "newline-separated for multiple headers" to the description. [line 868] [Source]

Skills [Source]

• Updated hooks reference link from generic "Hooks" to specific "Hooks in skills and agents" section. [line 196] [Source]

Sub-agents [Source]

• Clarified that all hook events are supported in subagents. [line 379] [Source]
• Added explanation to Stop event: "When the subagent finishes (converted to SubagentStop at runtime)". [line 385] [Source]
• Clarified SubagentStop matcher behavior: "SubagentStop fires for all subagent completions regardless of matcher values". [line 420] [Source]

Troubleshooting [Source]

• Updated hook example link from generic "markdown formatting hook example" to specific "Auto-format code after edits" section reference. [line 425] [Source]

API changes

Changed documents

Remote MCP servers [Source]

• Removed Granola MCP server from the list. [line 63] [Source]
• Added Google Cloud BigQuery MCP server: "BigQuery: Advanced analytical insights for agents" (URL: https://bigquery.googleapis.com/mcp). [line 367] [Source]
• Added LILT MCP server: "High-quality translation with human verification" (URL: https://mcp.lilt.com/mcp). [line 455] [Source]
• Added Make MCP server: "Run Make scenarios and manage your Make account" (URL: https://mcp.make.com). [line 471] [Source]
• Added Wyndham Hotels and Resorts MCP server: "Discover the right Wyndham Hotel for you, faster" (URL: https://mcp.wyndhamhotels.com/claude/mcp). [line 679] [Source]

Text editor tool [Source]

• Corrected parameter name from new_str to insert_text for the insert command. [line 160] [Source]