Skill Claude CodeCodex
Build HTTP servers with effect/unstable/http — HttpRouter routes and middleware, HttpServerRequest schema decoding, HttpServerResponse constructors, multipart uploads, websocket upgrades, static files, NodeHttpServer/BunHttpServer layers, and in-memory web handlers. Use when serving raw HTTP routes, reading request…
Skill Claude CodeCodex
Incrementally migrate existing async/Promise-based modules to Effect services while preserving backward compatibility. Use this skill when effectifying an existing module, replacing async facades with Effect services, or maintaining dual async/Effect APIs during migration.
Skill Claude CodeCodex
Design and compose Effect layers for clean dependency management.
Skill Claude CodeCodex
Bridge Effect services into non-Effect frameworks (Hono, Express, Fastify, Lambda, Workers) using ManagedRuntime. Use this skill when you need to run Effects outside of runMain — in HTTP handlers, serverless functions, or any embedded context where Effect doesn't own the process lifecycle.
Skill Claude CodeCodex
Build MCP (Model Context Protocol) servers with Effect using McpServer, McpSchema, Tool, and Toolkit. Use this skill when implementing MCP servers that expose tools, resources, and prompts to LLM clients via stdio or HTTP transports.
Skill Claude CodeCodex
Implement structured logging, distributed tracing, and metrics in Effect applications. Use this skill when configuring loggers, adding spans/tracing, collecting metrics, or setting up OTLP/Prometheus export.
Skill Claude CodeCodex
Use Effect Optic for composable, type-safe access and immutable updates to nested data structures. Covers Iso, Lens, Prism, Optional, and Traversal — when to use each, how to compose them, and practical patterns for deep updates, tagged unions, and filtered collections.
Skill Claude CodeCodex
Run Effect computations concurrently with Effect.all/forEach concurrency options, racing combinators (race, raceAll, raceFirst), and coordination primitives (Semaphore, PartitionedSemaphore, Latch). Use when fanning out work over a collection, limiting parallelism, racing alternatives for first-success, enforcing…
Skill Claude CodeCodex
Use effect Path for platform-abstract file path operations including joining, resolving, and URL conversion.
Skill Claude CodeCodex
Master Effect pattern matching using Data.TaggedEnum, $match, $is, Match.typeTags, and Effect.match. Avoid manual tag checks and Effect.result patterns. Use this skill when working with discriminated unions, ADTs, or conditional logic based on tagged types.
Skill Claude CodeCodex
Use Effect platform abstractions for cross-platform file I/O, process spawning, HTTP clients, cryptography, and terminal I/O. Apply when writing filesystem/process/HTTP/crypto/console code that must stay portable across Node.js, Bun, and browser adapters.
Skill Claude CodeCodex
Structure Effect platform layer provision for cross-platform applications using Effect platform abstractions.
Skill Claude CodeCodex
Build typed event buses using Effect PubSub and Stream. Use this skill when implementing publish/subscribe communication between services, replacing callback-based event systems, or building reactive service architectures with typed event streams.
Skill Claude CodeCodex
Build composable React components using Effect Atom for state management. Use this skill when implementing React UIs that avoid boolean props, embrace component composition, and integrate with Effect's reactive state system.
Skill Claude CodeCodex
Implement the VM pattern using Effect and Effect-Atom for reactive, testable frontend state management. Use this skill when building React applications with View Models that bridge domain services and UI.
Skill Claude CodeCodex
Define type-safe RPC contracts with effect/unstable/rpc — Rpc.make payload/success/error/defect schemas, RpcSchema.Stream streaming responses, RpcGroup composition (add/merge/omit/prefix/annotate), and RpcMiddleware.Service definitions shared by client and server. Use when declaring or evolving RPC procedures…
Skill Claude CodeCodex
Consume typed RPC services with Effect's RpcClient — protocol layers (HTTP, WebSocket, TCP, worker, in-memory), RpcSerialization codecs, per-call and ambient headers, streaming calls, interruption, reconnection, and RpcClientError handling. Use when calling an RpcGroup from a client, wiring a client transport +…
Skill Claude CodeCodex
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.
Skill Claude CodeCodex
Serve RpcGroup contracts with Effect's RpcServer — handler layers (RpcGroup.toLayer/toLayerHandler), protocol layers (HTTP, WebSocket, TCP, stdio, worker), RpcSerialization, server middleware, streaming results, interruption and shutdown semantics, RpcTest. Use when implementing the server side of an Effect RPC API…
Skill Claude CodeCodex
Master Effect Schema composition patterns including Schema.decodeTo, transformations, filters, and validation. Use this skill when working with complex schema compositions, multi-step transformations, or when you need to validate and transform data through multiple stages.
Skill Claude CodeCodex
Authoritative reference for Effect Schema v4 API changes and migration patterns from v3. Use this skill when writing Schema code to avoid v3 patterns, when migrating existing v3 Schema code, or when unsure about current Schema API names.
Skill Claude CodeCodex
Manage resource lifecycles with Effect Scope — Effect.acquireRelease/addFinalizer/scoped/scopedWith, onExit/ensuring finalizers, manual Scope.make/close/fork, ScopedRef, and scope ownership in Layers and fibers. Use when acquiring anything that needs guaranteed cleanup (file handles, connections, event listeners, temp…
Skill Claude CodeCodex
Implement Effect services as fine-grained capabilities avoiding monolithic designs.
Skill Claude CodeCodex
Build bidirectional socket transports with effect/unstable/socket — the Socket run/writer surface, WebSocket-backed sockets, TCP/Unix-domain clients via NodeSocket, SocketServer accept loops, channel adapters, the SocketError taxonomy, and reconnect patterns. Use when connecting to or serving raw TCP, Unix-domain, or…