Effect 3

Apply Effect 3 semantics from project-local architecture, the narrowest relevant reference, and source matching the target's installed packages.

Workflow

Do not activate this workflow merely because a file imports effect. For nontrivial Effect work:

1. Resolve the target package or workspace and its exact installed effect and relevant @effect/* versions. If effect is not 3.x, stop because this skill does not apply.
2. Inspect neighboring services, layers, errors, schemas, runtime boundaries, and tests. Local conventions decide organization; installed package evidence decides API facts.
3. Read references/critical-rules.md, then only the task-specific references below.
4. Verify every uncertain import, signature, or behavior against the package installation visible to the target workspace before editing.
5. Implement the smallest pattern consistent with the project and run the narrowest test or typecheck covering the changed semantics.