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Write a Shiitake extension

Extensions add your own behaviour to a Shiitake Agent; the guide lives on the Shiitake site.

A Shiitake extension adds behaviour to an Agent: a prompt section, a tool the model can call, stored state, commands and a client panel. The step-by-step guide lives with the Shiitake package:

  • Your first extension starts with a ten-line extension and runs it without an API key.
  • Each later page adds one idea, up to a complete Bookmarks extension with tests.
  • The Extension reference lists every contribution and the capability it needs.

Extensions you write run on hosts you run, such as a Cloudflare Durable Object or your own tests; Fungi-hosted Agents load Fungi’s own extensions.