Effect

Use this skill when a Bun service uses Effect as its application framework. Prefer the target repository's local instructions for exact package versions and commands.

• Model expected failures with typed errors rather than unchecked exceptions.
• Build dependencies as explicit layers and provide them at the application boundary.
• Keep promise, callback, and request-framework interop at narrow adapter boundaries.
• Use scoped resources for connections, handles, and subscriptions that require cleanup.
• Run the repository's formatter and linter before bun typecheck and its focused tests.