Claude-Code v2.1.91 adds MCP result persistence, shell execution controls, and multi-line deep links

Claude-Code v2.1.91 Release Notes

Claude-Code v2.1.91 includes several new features, bug fixes, and performance improvements for developers using AI coding agents. The release focuses on enhancing tool integration, security controls, and user experience.

New Features

• MCP tool result persistence override: Added support for _meta["anthropic/maxResultSizeChars"] annotation allowing results up to 500K characters to pass through without truncation. This enables larger data like database schemas to persist in tool results.
• Shell execution control: Added disableSkillShellExecution setting to disable inline shell execution in skills, custom slash commands, and plugin commands.
• Multi-line deep links: Added support for multi-line prompts in claude-cli://open?q= deep links. Encoded newlines (%0A) are no longer rejected.
• Plugin executables: Plugins can now ship executables under bin/ and invoke them as bare commands from the Bash tool.

Bug Fixes

• Fixed transcript chain breaks on --resume that could lose conversation history when async transcript writes fail silently
• Fixed cmd+delete not deleting to start of line on iTerm2, kitty, WezTerm, Ghostty, and Windows Terminal
• Fixed plan mode in remote sessions losing track of the plan file after container restart, which caused permission prompts on plan edits and empty plan-approval modals
• Fixed JSON schema validation for permissions.defaultMode: "auto" in settings.json
• Fixed Windows version cleanup not protecting the active version's rollback copy
• /feedback now explains why it's unavailable instead of disappearing from the slash menu

Improvements

• Improved /claude-api skill guidance for agent design patterns including tool surface decisions, context management, and caching strategy
• Improved performance: faster stripAnsi on Bun by routing through Bun.stripANSI
• Edit tool now uses shorter old_string anchors, reducing output tokens