microfn

microfn is a sandboxed cloud environment for building, deploying, and running tiny JavaScript functions, designed to be AI-friendly. It gives Claude its own workspace to write functions, deploy them, manage their code and secrets, and run the functions you've already built.

With microfn, Claude can:

• Write and deploy a new JavaScript function on request
• Inspect, update, and validate the code of existing functions
• Manage function settings and secrets
• Run your functions and use their results in the conversation

Each function runs in an isolated sandbox, so Claude can create and combine its own tools: fetch a weather API, keep data in a key-value store, post to Slack, or send a Telegram message.

Sign in with your microfn account over OAuth. The free plan includes 3 active functions and 100 executions per day, and Pro ($4.99/month) removes both limits.