Effect Skill Index
Use this as a quick router to the right Skill for your task. Each entry links to a focused Skill optimized for a coding agent’s limited context.
Decision Tree I need to write or refactor some Effect code → Foundations I need robust error handling/retries → Errors & Retries I must run things in parallel / manage fibers → Concurrency & Fibers This is a data pipeline / batching / backpressure → Streams & Pipelines I need DI/services/layers or test/live wiring → Layers & Services Opening files/sockets/servers with cleanup → Resources & Scope Add HTTP endpoints / JSON responses → HTTP & Routing Validate inputs / parse config → Config & Schema Value-based equality / high-perf immutable collections → Data Structures Time, logging, spans/tracing → Time/Tracing/Logging Queues, PubSub, background workers → Queues & Background Write tests/mocks for services → Testing & Mocking Looking for specific patterns or examples → Patterns Hub (130+ patterns) Cross-Skill Patterns
All patterns are now available locally in the Patterns Hub (130+ patterns):
Retry transient failures → Errors & Retries + retry-based-on-specific-errors.mdx Resource-safe streaming → Streams & Pipelines + stream-manage-resources.mdx Graceful shutdown → Queues & Background + execute-long-running-apps-with-runfork.mdx Service layer design → Layers & Services + model-dependencies-as-services.mdx HTTP server setup → HTTP & Routing + build-a-basic-http-server.mdx Schema validation → Config & Schema + define-contracts-with-schema.mdx Testing with mocks → Testing & Mocking + mocking-dependencies-in-tests.mdx
Tip: For any "How do I...?" question, check the Patterns Hub decision tree first!
Local Source Reference
CRITICAL: Always search local Effect source before implementing
The full Effect source code is available at docs/effect-source/. Every Effect skill now includes a "Local Source Reference" section with:
Key source files for that skill's domain Example grep commands to find implementations Workflow for searching before coding Quick Access to Source All Effect packages: docs/effect-source/ Core library: docs/effect-source/effect/src/ Platform APIs: docs/effect-source/platform/src/ SQL: docs/effect-source/sql/src/ Schema: docs/effect-source/schema/src/ Example: Finding Effect.gen grep -F "Effect.gen" docs/effect-source/effect/src/Effect.ts
Workflow Reminder Read the relevant skill (from decision tree above) Review the skill's "Local Source Reference" section Search the Effect source code for the API you need Study the implementation and types Write your code based on real implementations
See CLAUDE.local.md for complete source reference guide
References Agent Skills overview: Introducing Agent Skills Skills guide: Claude Code Skills Documentation Local Patterns Hub: ../effect-patterns-hub/SKILL.md (130+ patterns) Pattern Documentation: ../../docs/effect-patterns/ AGENTS.md: ../../AGENTS.md (Effect best practices for AI agents) EffectPatterns (upstream source): PaulJPhilp/EffectPatterns