Effect Ts

This is a corrections guide disguised as a skill reference, and that's exactly what you need if you're building Effect-TS applications with Claude. LLMs routinely hallucinate Effect APIs like `Effect.cachedWithTTL` and `Effect.match` that don't exist, so this skill frontloads a table of wrong versus correct patterns. The meat is in the concurrency and resource management sections, especially fiber interruption for MCP servers where client disconnects need proper cleanup. It won't teach you Effect from scratch, but if you're already using it and tired of fixing AI-generated code that looks plausible but doesn't compile, this cuts through the noise. The "when not to use Effect" section is refreshingly honest about the learning curve and bundle size costs.