[](https://pkg.pr.new/~/Effect-TS/effect) # Effect Effect is a library for building robust, maintainable, type-safe, and production grade applications in TypeScript. > **Effect V4 is currently in beta.** The `main` branch contains v4 development. ## Install V4 Beta ```sh npm install effect@beta ``` ## Effect v3 The Effect v3 source code is available on the [`v3`](https://github.com/Effect-TS/effect/tree/v3) branch. ```sh npm install effect@latest ``` Issues and pull requests meant for Effect v3 should target the [`v3`](https://github.com/Effect-TS/effect/tree/v3) branch. ## 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