Effect
TypeScript library providing functional programming utilities and effects system for production-grade software.
Languages, types and runtimes npm MIT
Used in agent projects
22
0.2% of 12,697 public repos built with AI coding agents
Rank in languages, types and runtimes
#15 of 18
by use in those projects
Downloads
44.6M
npm, last 7 days, effect
GitHub stars
17.2K
last push Oct 10, 2026
How Effect is used
Effect is a dependency in 22 of the 12,697 public GitHub projects set up for AI coding agents that we scanned (0.2%), #15 of 18 in languages, types and runtimes. The most used alternative there is TypeScript. Projects that use it most often also use Vitest (63.6%), TypeScript (95.5%), Biome (36.4%).
Often used with Effect
| Vitest | 63.6% of Effect projects · 5.2× more than average |
|---|---|
| TypeScript | 95.5% of Effect projects · 1.7× more than average |
| Biome | 36.4% of Effect projects · 10.4× more than average |
| oxlint | 31.8% of Effect projects · 19.6× more than average |
| tsx | 31.8% of Effect projects · 3.2× more than average |
| Drizzle ORM | 22.7% of Effect projects · 8.9× more than average |
| Playwright (JavaScript) | 27.3% of Effect projects · 3.1× more than average |
| Zod | 36.4% of Effect projects · 2.1× more than average |
By coding agent
| Claude Code | 0.4% of projects set up for it |
|---|---|
| Cursor | 0.5% of projects set up for it |
| GitHub Copilot | 0.3% of projects set up for it |
| OpenAI Codex | 1.3% of projects set up for it |
Share of public repos configured for each agent that list Effect as a dependency.
Install
| Package | npm install effect |
|---|---|
| Main stacks | TypeScript / JavaScript (18), Next.js (2), Python (1), React Native / Expo (1) |
| Example projects | floydspace/effect-aws, beep-effect/beep-effect, longtail-labs/slide.code, Resnovas/smartcloud, PaulJPhilp/EffectiveAgent |
Alternatives to Effect
| Tool | Used in agent projects | Downloads / wk | GitHub stars | License |
|---|---|---|---|---|
| TypeScript npm Language for application-scale JavaScript development with static type checking. |
7,092 (55.9%) | 305M | 111K | Apache-2.0 |
| tsx npm Node.js enhanced with esbuild to run TypeScript and ESM files. |
1,262 (9.9%) | 96.8M | 12.2K | MIT |
| ts-node npm TypeScript execution environment for Node.js with source map support. |
865 (6.8%) | 45.6M | 13.1K | MIT |
| vue-tsc npm TypeScript type checker for Vue.js single-file components. |
111 (0.9%) | 6.5M | 6,724 | MIT |
| tsconfig-paths npm Module resolution utility that loads Node.js modules according to TypeScript path mappings. |
86 (0.7%) | 113M | 1,908 | MIT |
| Cloudflare Workers Types npm TypeScript type definitions for Cloudflare Workers runtime. |
84 (0.7%) | 12.1M | 8,888 | MIT OR Apache-2.0 |
| jiti npm Runtime TypeScript and ESM support for Node.js without build steps. |
84 (0.7%) | 19M | 2,973 | MIT |
| CFFI pypi Foreign Function Interface for calling C code from Python. |
84 (0.7%) | 248M | 280 | — |