effect-patterns-services-agents

Define a class extending Context.Tag or use the modern Effect.Service constructor with an effect that returns the service implementation. Consumers access it with yield* MyService inside Effect.gen, and layers provide the implementation at runtime.

Combine service layers using Layer.mergeAll to build a single application layer, then supply it to your program with Effect.provide. This wires all dependencies, such as config, cache, and rate limiter services, into the effect's context.

Errors are modeled as typed values using Data.TaggedError classes rather than thrown exceptions. Recover from specific failures with Effect.catchTag, which matches on the error's tag and lets you handle each failure type explicitly.

Context.Tag is the classic way to declare a service identifier and its interface. Effect.Service is the newer form that generates the tag and layer together from a single definition, reducing boilerplate for common service setups.

This repository's convention avoids path aliases entirely. Use workspace:* dependencies between packages and run scripts from the project root so module resolution works correctly during debugging and execution.