facebook/flow
Adds static typing to JavaScript to improve developer productivity and code quality. observed · 2026-10-17
Health v2 · maintenance only
95/100
- Activity 100
- Release rhythm 87
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-10-21. Adoption (stars, forks) is never an input.
- gap_med: 5.0
- age_days: 4375
- days_rel: 5
- days_push: 4
- n_releases_24m: 109
Adoption not part of the score
22296 stars · 1893 forks observed · 2026-10-17
What it is AI-extracted, prompt v1, taxonomy v1, 2026-10-12, confidence 0.98
Flow is a static type checker for JavaScript that adds optional type annotations to improve code safety and developer productivity. It is implemented in Rust and distributed as a command‑line tool with binary releases for major platforms.
Use cases
- add static type checking to an existing JavaScript codebase
- catch type errors early during development of React applications
- enforce strict object shape contracts in a large JavaScript project
- integrate Flow parsing into custom tooling via the flow‑parser npm package
- migrate a TypeScript‑like codebase to Flow for stronger static guarantees
- validate JavaScript libraries before publishing to npm
When to choose
- you prefer Flow's exact object types and React component syntax over TypeScript
- your project already uses Babel and can incorporate flow‑remove‑types
- you need a fast, Rust‑based type checker with binary distributions for all major OSes
When to avoid
- you require a type system that emits compiled JavaScript code directly
- your team is heavily invested in the TypeScript ecosystem and tooling
- you need built‑in support for features that only TypeScript provides
Facets
cli-tool · maturity active
parser cli programming-languages web-development windows cli static-typing javascript flowtype rust type-checker linux macos
8 sources
- readme: https://github.com/facebook/flow · fetched 2026-10-17 · baac2b03f543
- homepage: https://flow.org/ · fetched 2026-09-28 · 06c26ec64d6d
- site_page: https://flow.org/en/docs/getting-started · fetched 2026-09-28 · 0f549cd5a4f4
- site_page: https://flow.org/en/docs · fetched 2026-09-28 · 1a6376963469
- site_page: https://flow.org/en/docs/flow-vs-typescript · fetched 2026-09-28 · f0d07b015fef
- site_page: https://flow.org/en/docs/react/component-syntax · fetched 2026-09-28 · c67a895df9b8
- site_page: https://flow.org/en/docs/match · fetched 2026-09-28 · fae2e56a66cf
- site_page: https://flow.org/en/docs/types/objects · fetched 2026-09-28 · be1715476070
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| facebook/flow | main | 95 |
For agents
Data as of 2026-10-19T08:05:51.212177+00:00 · Report a problem