Manage concurrency and error handling in TypeScript apps with a unified library
Have you ever struggled with how a server handles many concurrent requests or how to recover when an external call fails? Effect is a tool that combines these problems with the type system to help code detect and handle errors on its own. It is not just a utility; it is a library that integrates the core concepts needed to design application structure.
Long-term support for version 4.x
Effect 4.x is a long-term support (LTS) release that provides bug and security fixes for at least three years. After the next major version is released, it continues with bug fixes for one year and security fixes for two years. Stable APIs change only in major versions, while unstable or experimental APIs may change in minor or patch versions. This means a predictable maintenance environment when building systems that will run for years.
Problem solving based on type safety
Effect uses TypeScript's strict type checking to catch runtime errors at compile time. It handles complex problems that arise in large-scale systems, such as dependency injection, structured concurrency, scheduling, tracing, and schema validation, in a single integrated way. This improves code readability and maintainability, allowing team members to write code using the same patterns.
Integration with various environments and databases
This repository includes service packages for various platforms such as browser, Bun, Deno, and Node.js, in addition to the core package. It also provides clients for several databases, including ClickHouse, MySQL, PostgreSQL, and SQLite. You can also enhance observability with integration packages for AI services like OpenAI and Anthropic, as well as an OpenTelemetry integration package. All packages are released together with the same version to reduce compatibility issues.
Requirements to check before use
To use Effect, you need TypeScript 5.9 or higher, Node.js 18 or higher, and the strict flag enabled in tsconfig.json. Some integration packages may require newer runtimes; for example, @effect/sql-sqlite-node requires Node.js 22.16 or higher. If you are currently using Effect 3.x, you should upgrade to 4.x by referring to the migration guide. It is distributed under the MIT license, and support is available through official documentation and the Discord community.