# libuv/libuv

Cross-platform asynchronous I/O

Repository: https://github.com/libuv/libuv
Canonical: https://ross.abutalabs.com/products/libuv
Homepage: https://libuv.org/
Language: C
License: MIT
License Family: permissive
Topics: asynchronous, io, networking, unix, windows, velociraptors, unicorns, deep-io
Last push: 2026-08-20T09:27:28+00:00

## Health v2 (maintenance only)
Score: 85/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 61, longevity 100
- inputs: {"age_days": 4660, "days_push": 13, "days_rel": 180, "gap_med": 55.5, "n_releases_24m": 7}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 27131, forks 3924 (observed 2026-08-28T04:11:47.415928+00:00)

## What it is
libuv is a cross-platform C library providing asynchronous I/O via a full-featured event loop backed by epoll, kqueue, IOCP, and event ports. Originally built for Node.js, it also powers Luvit, Julia, and uvloop, offering async TCP/UDP sockets, DNS resolution, file system operations, threading, and child process management.

## Use cases
- write a cross-platform async TCP server in C
- build an event loop for a scripting language runtime
- perform asynchronous file system operations portably
- watch for file system changes on Linux and Windows
- run background work on a thread pool
- resolve DNS asynchronously in a native application
- spawn and manage child processes cross-platform

## When to choose
- you need a battle-tested, portable async I/O layer in C or C++
- you are building a runtime, interpreter, or server that needs an event loop
- you want one API covering epoll, kqueue, and IOCP without platform-specific code
- you need stable ABI and SemVer guarantees for long-lived native dependencies

## When to avoid
- you are writing high-level application code where a language-native async runtime is easier
- you need only simple blocking I/O and don't want an event loop dependency
- you want a pure-Windows or pure-Unix API with deeper platform-specific features

## Facets
- artifact type: library
- maturity: stable
- function: concurrency, networking, file-system, developer-tools
- domain: developer-tools, cross-platform, networking, operating-systems
- platform: windows, cross-platform, cpp, c
- tags: event-loop, async-io, c-library, nodejs, tcp, udp, dns, thread-pool, linux, macos

## Member repositories
- libuv/libuv (main) score 85

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:47.415928+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:54:35.154329+00:00, confidence not recorded.
  - readme: https://github.com/libuv/libuv (fetched 2026-08-28T04:11:47.415928+00:00, sha 2fc934ebd3b8)
  - homepage: https://libuv.org/ (fetched 2026-08-29T07:51:52.644399+00:00, sha dcd64d216dd8)
  - site_page: https://docs.libuv.org (fetched 2026-08-29T07:51:52.647486+00:00, sha 1bb22428e0d4)
  - site_page: https://dist.libuv.org/dist (fetched 2026-08-29T07:51:52.649767+00:00, sha d45eb7f31078)
- Data as of 2026-08-30T08:39:29.467469+00:00.