Anthropic Previews Function Hooks, a New Extension Mechanism for Claude Code
On September 4, Anthropic's Claude developer account @ClaudeDevs previewed Function Hooks, a proposed extension mechanism for Claude Code. The feature is not yet live; the team released several demo videos and is collecting community feedback via GitHub issue #91870.
Confirmed
- Function Hooks let users hook into Claude Code via TypeScript functions, modeled on the Express/Koa middleware pattern and executed in registration order, enabling deep extension and customization of Claude Code's behavior
- The proposal's technical architecture was published in GitHub issue #91870, with the team stating it wants to make Claude Code more extensible
Unconfirmed
- Specific API details and an official release date have not been announced; this remains a proposal with demos
Why it matters
- A middleware-style hook model would let developers intercept Claude Code's execution flow without modifying the product itself, a significant step toward an open plugin ecosystem for Claude Code
2026-09-04 ~ 2026-09-04 · 5 related posts
Primary sources
- [source] Anthropic previews Function Hooks: deep TypeScript-level customization for Claude Code — ClaudeDevs · 2026-09-04
- [source] Claude Code Function Hooks proposal: Express-style middleware to make plugins 10x more powerful — ClaudeDevs · 2026-09-04
- Anthropic explores Function Hooks, a new way to extend Claude Code, seeking feedback — EricBuess · 2026-09-04