Effect Index

This is your router for the Effect ecosystem when you're working with Claude Code. It's a decision tree that maps common tasks (error handling, concurrency, HTTP, testing) to 12 focused skills, each optimized for an agent's limited context window. The real value is the cross-skill pattern index with 130+ examples pulled from the Effect Patterns repository, so you can jump straight to retry-based-on-specific-errors.mdx or stream-manage-resources.mdx instead of starting from scratch. It also reminds you to grep the local Effect source code before implementing anything, which is the right workflow but easy to forget when you're moving fast.