#Effect

Effect is a library for building robust, maintainable, type-safe, and production grade applications in TypeScript. It helps you handle the hard problems at scale: typed errors, dependency injection, structured concurrency, scheduling, tracing, and unified schema validation.

Effect V4 is currently a release candidate. The main branch contains v4 development.

#Install V4 RC

npm install effect@rc

#Requirements

TypeScript 5.9 or newer. TypeScript 7 is recommended for the best performance and compatibility with Effect's TypeScript tooling.
Node.js 18 or newer is the general minimum for running Effect on Node.js. Some integration packages require newer runtimes; for example, @effect/sql-sqlite-node requires Node.js 22.16 or newer.
Strict type-checking: the strict flag must be enabled in your tsconfig.json.

#Effect v3

The Effect v3 source code is available on the v3 branch, which is also where issues and pull requests meant for Effect v3 should be targeted.

#Packages

This monorepo contains the core effect package alongside integration packages that extend it. All v4 packages are published under the rc tag on npm.

Package	Description	API Reference
`effect`	The core package	docs
`@effect/platform-browser`	Platform services for the browser	docs
`@effect/platform-bun`	Platform services for Bun	docs
`@effect/platform-deno`	Platform services for Deno	docs
`@effect/platform-node`	Platform services for Node.js	docs
`@effect/platform-node-shared`	Shared services for Node.js-compatible runtimes	docs
`@effect/sql-clickhouse`	SQL client for ClickHouse	docs
`@effect/sql-d1`	SQL client for Cloudflare D1	docs
`@effect/sql-libsql`	SQL client for libSQL	docs
`@effect/sql-mssql`	SQL client for Microsoft SQL Server	docs
`@effect/sql-mysql2`	SQL client for MySQL	docs
`@effect/sql-pg`	SQL client for PostgreSQL	docs
`@effect/sql-pglite`	SQL client for PGlite	docs
`@effect/sql-sqlite-bun`	SQL client for SQLite via `bun:sqlite`	docs
`@effect/sql-sqlite-do`	SQL client for Cloudflare Durable Objects SQLite	docs
`@effect/sql-sqlite-node`	SQL client for SQLite via `node:sqlite`	docs
`@effect/sql-sqlite-react-native`	SQL client for SQLite in React Native	docs
`@effect/sql-sqlite-wasm`	SQL client for SQLite compiled to WebAssembly	docs
`@effect/ai-anthropic`	Anthropic provider for the Effect AI modules	docs
`@effect/ai-openai`	OpenAI provider for the Effect AI modules	docs
`@effect/ai-typesafe`	TypeSafe decision provider for the Effect AI modules	docs
`@effect/ai-openai-compat`	OpenAI-compatible API provider for the Effect AI modules	docs
`@effect/ai-openrouter`	OpenRouter provider for the Effect AI modules	docs
`@effect/atom-react`	React bindings for Effect Atom	docs
`@effect/atom-solid`	SolidJS bindings for Effect Atom	docs
`@effect/atom-vue`	Vue bindings for Effect Atom	docs
`@effect/opentelemetry`	OpenTelemetry integration	docs
`@effect/vitest`	Helpers for testing with Vitest	docs
`@effect/docgen`	Documentation generator for Effect projects	docs
`@effect/doctest`	Runs JSDoc examples as Vitest tests	docs
`@effect/openapi-generator`	Generate Effect code from OpenAPI specifications	docs

#Resources

Documentation (https://effect.website)
Discord (https://discord.gg/effect-ts)
Effect v3 source (https://github.com/Effect-TS/effect/tree/v3)
Effect v4 source (https://github.com/Effect-TS/effect/tree/main)

#License

MIT