do-coding-standards

Follow the five-step workflow: establish local rules from AGENTS.md and configs, trace the changed behavior and load applicable references, design from public types inward, implement the complete behavior, then verify through public interfaces with the repository's checks.

Expected failures are modeled as typed values using custom tagged errors such as Schema.TaggedErrorClass, while throws are reserved for defects. The errors reference covers granular error types, stable message prefixes, and boundary translation.

Use an Effect service with a Layer when a capability owns persistence, external I/O, configuration, or has real production and test variation. Keep deterministic calculations, parsed inputs, and per-call options as plain values instead of services.

Yes. The core principles apply to plain TypeScript using a small local Result tagged union or better-result, with Effect-specific guidance isolated in dedicated references that only apply when Effect code changes.

Tests exercise behavior through real public interfaces using real or faithful in-memory implementations rather than module mocks. Effect tests use it.effect, TestClock for time, and reusable test Layers that cross the production service tag.