Implement typed error handling in Effect v4 using Schema.TaggedErrorClass, catchTag/catchTags, catchReason/catchReasons, Cause, ErrorReporter, and recovery patterns. Use this skill when working with Effect error channels, handling expected failures, or designing error recovery strategies.
Build typed HTTP APIs with Effect's HttpApi — endpoints with schemas, handlers, security middleware, OpenAPI docs, derived clients, and handler unit tests. Use when building HTTP servers, REST APIs, or typed HTTP clients with Effect v4.
Build typed RPC endpoints and cluster-distributed entities, singletons, cron jobs, and durable workflows with Effect's RPC and Cluster modules (Rpc/RpcGroup/RpcServer/RpcClient, Entity/Sharding/Singleton, Node/Bun bundles). Use when building RPC services or distributed/clustered Effect systems.