Menu
Quick lookup for Effect TypeScript library APIs, patterns, and source code. Use when you need to find Effect functions, understand Effect patterns, or look up implementation details.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Based on SOC occupation classification
| name | effect-lookup |
| version | 1.0.0 |
| description | Quick lookup for Effect TypeScript library APIs, patterns, and source code. Use when you need to find Effect functions, understand Effect patterns, or look up implementation details. |
Quick reference for finding and understanding Effect TypeScript library APIs from local source code.
Source code is available locally and on GitHub. Check local first, fall back to GitHub if not available.
| Repo | Local path | GitHub |
|---|---|---|
| Effect | opensrc/repos/github.com/effect-ts/effect/ | https://github.com/effect-ts/effect |
| EffectPatterns | opensrc/repos/github.com/PaulJPhilp/EffectPatterns/ | https://github.com/PaulJPhilp/EffectPatterns |
Use this skill when:
The effect-docs MCP server provides indexed documentation:
mcp__effect-docs__effect_docs_search: Search for Effect concepts
mcp__effect-docs__get_effect_doc: Get specific documentation by ID
For implementation details, search the local source at opensrc/repos/github.com/effect-ts/effect/:
# Find a specific function
grep -r "export const myFunction" opensrc/repos/github.com/effect-ts/effect/packages/effect/src/
# Find usage patterns
grep -rn "Effect.gen" opensrc/repos/github.com/effect-ts/effect/packages/effect/src/
# Find type definitions
grep -rn "interface MyType" opensrc/repos/github.com/effect-ts/effect/packages/effect/src/
Core modules are at: opensrc/repos/github.com/effect-ts/effect/packages/effect/src/<Module>.ts
Example: To understand Effect.map, read opensrc/repos/github.com/effect-ts/effect/packages/effect/src/Effect.ts
| Task | Reference |
|---|---|
| Module categories | references/modules.md |
| Common patterns | references/patterns.md |
opensrc/repos/github.com/effect-ts/effect/
โโโ packages/
โ โโโ effect/ # Core Effect library
โ โ โโโ src/ # Source files (Effect.ts, Layer.ts, etc.)
โ โโโ platform/ # Cross-platform utilities (HTTP, FileSystem)
โ โโโ platform-node/ # Node.js platform implementation
โ โโโ platform-browser/ # Browser platform implementation
โ โโโ cli/ # CLI building utilities
โ โโโ sql/ # SQL database utilities
โ โโโ sql-pg/ # PostgreSQL implementation
โ โโโ sql-kysely/ # Kysely integration
โ โโโ rpc/ # Remote procedure calls
โ โโโ cluster/ # Distributed computing
โ โโโ opentelemetry/ # OpenTelemetry integration
โ โโโ experimental/ # Experimental features
โ โโโ ai/ # AI integrations (OpenAI, Anthropic, etc.)
| Module | File | Purpose |
|---|---|---|
| Effect | Effect.ts | Core effect type and combinators |
| Layer | Layer.ts | Dependency injection layers |
| Context | Context.ts | Type-safe service context |
| Scope | Scope.ts | Resource management |
| Runtime | Runtime.ts | Effect execution |
| Module | File | Purpose |
|---|---|---|
| Option | Option.ts | Optional values |
| Either | Either.ts | Success/failure values |
| Chunk | Chunk.ts | Immutable arrays |
| HashMap | HashMap.ts | Immutable hash maps |
| HashSet | HashSet.ts | Immutable hash sets |
| List | List.ts | Immutable linked lists |
| Module | File | Purpose |
|---|---|---|
| Fiber | Fiber.ts | Lightweight threads |
| Queue | Queue.ts | Concurrent queues |
| Ref | Ref.ts | Mutable references |
| Semaphore | Semaphore.ts | Concurrency limiting |
| PubSub | PubSub.ts | Publish/subscribe |
| Module | File | Purpose |
|---|---|---|
| Schema | Schema.ts | Data validation & encoding |
| ParseResult | ParseResult.ts | Parsing results |
| Arbitrary | Arbitrary.ts | Property-based testing |
| Module | File | Purpose |
|---|---|---|
| Stream | Stream.ts | Effectful streams |
| Sink | Sink.ts | Stream consumers |
| Channel | Channel.ts | Bidirectional streaming |
| Module | File | Purpose |
|---|---|---|
| Schedule | Schedule.ts | Retry/repeat schedules |
| Duration | Duration.ts | Time durations |
| DateTime | DateTime.ts | Date/time handling |
| Clock | Clock.ts | Time service |
| Cron | Cron.ts | Cron expressions |
| Module | File | Purpose |
|---|---|---|
| Config | Config.ts | Type-safe configuration |
| ConfigProvider | ConfigProvider.ts | Configuration sources |
# In Effect.ts, functions are well-documented with JSDoc
grep -A 20 "export const map" opensrc/repos/github.com/effect-ts/effect/packages/effect/src/Effect.ts
# Look for interface or type alias
grep -n "interface Effect<" opensrc/repos/github.com/effect-ts/effect/packages/effect/src/Effect.ts
# Tests often have practical examples
grep -rn "Effect.gen" opensrc/repos/github.com/effect-ts/effect/packages/effect/test/
# HTTP client/server
ls opensrc/repos/github.com/effect-ts/effect/packages/platform/src/Http*.ts
# FileSystem
cat opensrc/repos/github.com/effect-ts/effect/packages/platform/src/FileSystem.ts
Community-driven patterns and architectural guides at opensrc/repos/github.com/PaulJPhilp/EffectPatterns/.
# Browse pattern categories
ls opensrc/repos/github.com/PaulJPhilp/EffectPatterns/content/
# Search for a specific pattern
grep -rn "Layer" opensrc/repos/github.com/PaulJPhilp/EffectPatterns/content/
# Read docs
ls opensrc/repos/github.com/PaulJPhilp/EffectPatterns/docs/
Covers: getting started, core concepts, error management, resource management, concurrency, streams, scheduling, domain modeling, schema, platform, HTTP APIs, data pipelines, testing, and observability.
effect_docs_search for conceptual questions@effect/platform