Claude Code v2.1.9 Release Notes
Claude Code v2.1.9 brings enhanced MCP tool configuration, better session management, and improved terminal support for power users.
The Claude Code development team has released version 2.1.9, packed with thoughtful improvements for power users who rely on advanced AI-assisted coding workflows. This update focuses on enhancing the Model Context Protocol (MCP) experience, improving session management, and fixing critical issues that have been affecting long coding sessions.
What’s New
Enhanced MCP Tool Configuration
The standout feature in this release is the new auto:N syntax for configuring MCP tool search auto-enable thresholds. You can now set the context window percentage (0-100) to fine-tune when tools automatically activate, giving you precise control over your development environment’s behavior.
Improved File Organization
A new plansDirectory setting allows you to customize where plan files are stored, helping you maintain better project organization and workflow management.
Better Session Management
This release introduces session URL attribution to commits and pull requests created from web sessions, making it easier to track the origin of AI-assisted code changes. Additionally, skills can now access the current session ID through the ${CLAUDE_SESSION_ID} string substitution.
Enhanced User Experience
External editor support has been added to the AskUserQuestion “Other” input field via Ctrl+G, streamlining your coding workflow. The PreToolUse hooks now support returning additionalContext to the model, providing richer context for AI assistance.
Critical Bug Fixes
Several important issues have been resolved:
- Fixed long sessions with parallel tool calls that were failing with API errors about orphan tool_result blocks
- Resolved MCP server reconnection hanging issues when cached connection promises never resolved
- Fixed Ctrl+Z suspend functionality in terminals using the Kitty keyboard protocol (affecting Ghostty, iTerm2, kitty, and WezTerm users)
How to Update
To update to Claude Code v2.1.9, follow your usual update process. If you’re using a package manager, check for updates in your Claude Code installation. For manual installations, download the latest version from the official release page.