Claude-skill-registry effect-lookup

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

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/effect-lookup" ~/.claude/skills/majiayu000-claude-skill-registry-effect-lookup && rm -rf "$T"

manifest: skills/data/effect-lookup/SKILL.md

source content

Effect Library Lookup

Quick reference for finding and understanding Effect TypeScript library APIs from the local git subtree at

docs/effect/

When to Use This Skill

Use this skill when:

Looking up Effect function signatures or implementations
Finding examples of Effect patterns (Effect.gen, Layer, Context, etc.)
Understanding how Effect modules work internally
Checking API availability or deprecation status
Learning Effect idioms from source code

How to Look Up Effect APIs

1. Use the Effect Docs MCP Server (Fastest)

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

2. Search the Git Subtree Source

For implementation details, search the local source at

docs/effect/

# Find a specific function
grep -r "export const myFunction" docs/effect/packages/effect/src/

# Find usage patterns
grep -rn "Effect.gen" docs/effect/packages/effect/src/

# Find type definitions
grep -rn "interface MyType" docs/effect/packages/effect/src/

3. Read Source Files Directly

Core modules are at:

docs/effect/packages/effect/src/<Module>.ts

Example: To understand

Effect.map

, read

docs/effect/packages/effect/src/Effect.ts

Quick Reference

Task	Reference
Module categories	`references/modules.md`
Common patterns	`references/patterns.md`

Package Structure

docs/effect/
├── packages/
│   ├── effect/               # Core Effect library
│   │   └── src/              # Source files (Effect.ts, Layer.ts, etc.)
│   ├── platform/             # Cross-platform utilities (HTTP, FileSystem)
│   ├── platform-node/        # Node.js platform implementation
│   ├── platform-browser/     # Browser platform implementation
│   ├── cli/                  # CLI building utilities
│   ├── sql/                  # SQL database utilities
│   ├── sql-pg/               # PostgreSQL implementation
│   ├── sql-kysely/           # Kysely integration
│   ├── rpc/                  # Remote procedure calls
│   ├── cluster/              # Distributed computing
│   ├── opentelemetry/        # OpenTelemetry integration
│   ├── experimental/         # Experimental features
│   └── ai/                   # AI integrations (OpenAI, Anthropic, etc.)

Core Modules Quick Lookup

Effect System

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

Data Types

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

Concurrency

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

Schema & Validation

Module	File	Purpose
Schema	`Schema.ts`	Data validation & encoding
ParseResult	`ParseResult.ts`	Parsing results
Arbitrary	`Arbitrary.ts`	Property-based testing

Streaming

Module	File	Purpose
Stream	`Stream.ts`	Effectful streams
Sink	`Sink.ts`	Stream consumers
Channel	`Channel.ts`	Bidirectional streaming

Scheduling & Time

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

Configuration

Module	File	Purpose
Config	`Config.ts`	Type-safe configuration
ConfigProvider	`ConfigProvider.ts`	Configuration sources

Common Lookup Patterns

Find Function Signature

# In Effect.ts, functions are well-documented with JSDoc
grep -A 20 "export const map" docs/effect/packages/effect/src/Effect.ts

Find Type Definition

# Look for interface or type alias
grep -n "interface Effect<" docs/effect/packages/effect/src/Effect.ts

Find Examples in Tests

# Tests often have practical examples
grep -rn "Effect.gen" docs/effect/packages/effect/test/

Check Platform APIs

# HTTP client/server
ls docs/effect/packages/platform/src/Http*.ts

# FileSystem
cat docs/effect/packages/platform/src/FileSystem.ts

External References

Effect Website - Official documentation
Effect API Reference - Full API docs
Effect Discord - Community support

Tips for Effective Lookups

Start with MCP search - Use
```
effect_docs_search
```
for conceptual questions
Read JSDoc comments - Effect source has excellent inline documentation
Check tests for examples - Test files show real usage patterns
Use module tables above - Quickly navigate to the right source file
Platform packages - HTTP, FileSystem, etc. are in
```
@effect/platform
```