• Tech Dev NotesTech Dev Notes
Apps
  • Lookup
  • Compare
Market movement
  • Charts
  • Rankings
Visual proof
  • Screens
  • Store listings
  • Icons
Stacks and releases
  • Tech stacks
  • Tool releases
  • Developers
More
  • X feature flags
  • Grokipedia
  • Blog
  • Follow on X
Skip to content

© 2026 Tech Dev Notes

RSSAboutAPIPrivacyTermsSitemap@techdevnotes
Claude Code

Anthropic · CLI

Claude Code 2.1.187

2.1.186→2.1.187·June 23, 2026 at 5:07 PM UTC

Patch release adding background mode flags, an MCP tool idle timeout setting, and several prompt refinements while removing the Slackbot MCP tools.

Changelog

  • [new] Added --background / --bg flags to start Claude Code in background mode.
  • [removed] Removed the six Slackbot MCP tools (mcp__slackbot__*).

Models & prompts

  • Refined instructions around design system handling, neutral color and typeface choices, and avoiding common AI-generated design patterns.
  • Updated focus mode and plan mode guidance for clearer behavior when those modes are active.
  • Adjusted context management and ambient context handling to reduce unnecessary narration.
  • Tweaked task verification steps and rejection messaging for tool use.

Under the hood

  • Added CLAUDE_CODE_MCP_TOOL_IDLE_TIMEOUT environment variable to control idle timeout for MCP tools.
  • Added CLAUDE_CHROME_CLASSIFIER_FLOOR environment variable.
  • Added several new Statsig feature gates related to client data caching, cowork Chrome auto mode, team memory, and startup announcements.
  • Removed three older feature gates (tengu_desktop_upsell_shown, tengu_fable5_launch_shown, tengu_slate_fern).

Upgrade notes

  • Projects relying on the removed Slackbot MCP tools will need to update their MCP configuration.

content/

Browse captured content/

Same tree as claude-code/latest/content for this version. Open the full browser for sidebar navigation between docs and other files.

Open content/ browser →

8 listed · 8 in tree

content/ browserNavigate docs, prompts, and root filesFolder index plus per-file pages with prev/next and a full file sidebar.
README.mdDocs2 KBpackage.jsonMetadata1.4 KBmanifest.jsonMetadata1.4 KBversion.jsonMetadata172 Bcli-wrapper.cjsCJS4.8 KBinstall.cjsCJS7 KBsdk-tools.d.tsTS132.4 KBLICENSE.mdDocs147 B
Older release← 2.1.186Newer release→ 2.1.190
All Claude Code releases →