Effect-TS/effect

Health v2 · maintenance only

Adoption not part of the score

15514 stars · 696 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Effect is a TypeScript library and ecosystem for building production-grade, type-safe applications, centered on the Effect type that encodes success, errors, and requirements as composable values. It provides typed errors, structured concurrency, dependency injection, retries, resource safety, schema validation, and built-in observability, with platform, SQL, AI, and reactivity integration packages.

Use cases

• handle errors in TypeScript with types instead of try/catch
• run concurrent tasks with bounded parallelism and cancellation
• add retries with exponential backoff to flaky operations
• do dependency injection in TypeScript with type-safe services
• build CLIs and HTTP servers in TypeScript
• validate and parse data with schemas
• add tracing and structured logging to a Node.js app
• integrate LLM providers like OpenAI and Anthropic in a typed app

When to choose

• you are building a large or long-lived TypeScript codebase where reliability, typed errors, and composability matter
• you need structured concurrency, resource safety, and observability out of the box
• you want a consistent ecosystem (HTTP, SQL, CLI, AI) built on one core
• your team is willing to invest in learning a functional-effect style

When to avoid

• small scripts or prototypes where the learning curve and runtime overhead are not justified
• teams that cannot adopt a non-idiomatic, functional programming style in TypeScript
• bundle-size-critical frontend code where even the Micro module may be too heavy
• codebases that must stay on plain Promise/async-await conventions

Facets

library · maturity stable

error-handling concurrency middleware logging tracing monitoring serialization cli http-server http-client workflow-automation scheduling configuration-management sdk developer-tools backend web-development apis large-language-models databases microservices cross-platform bun browser cross-platform wasm functional-programming typed-errors dependency-injection structured-concurrency resource-safety schema-validation observability opentelemetry effect-system monorepo streams reactivity nodejs deno typescript

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