# tidwall/neco

Concurrency library for C (coroutines)

Repository: https://github.com/tidwall/neco
Canonical: https://ross.abutalabs.com/products/neco
Language: C
License: MIT
License Family: permissive
Last push: 2026-05-30T11:43:48+00:00

## Health v2 (maintenance only)
Score: 63/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 85, release rhythm 35, longevity 62
- inputs: {"age_days": 877, "days_push": 95, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1371, forks 112 (observed 2026-08-28T04:04:32.001387+00:00)

## What it is
Neco is a small, fast C library providing concurrency via stackful coroutines with channels, mutexes, condition variables, and deadline/cancellation support. It ships as a single-file amalgamation with no dependencies and is designed for easy concurrent I/O and network programming in C.

## Use cases
- write concurrent network code in C without threads
- coroutines for C programs
- use channels and mutexes in C like Go
- concurrent file and socket I/O in C
- lightweight single-threaded concurrency runtime
- cancel long-running I/O with deadlines in C

## When to choose
- you need Go-like concurrency primitives in plain C
- you want a dependency-free single-file library
- your workload is I/O-bound and single-threaded
- you need Posix-friendly file-descriptor-based concurrency

## When to avoid
- you need a multi-core, multithreaded scheduler
- you prefer async/await or event-loop callback models
- you need first-class Windows support without limitations

## Facets
- artifact type: library
- maturity: active
- function: concurrency, networking, http-server, file-system
- domain: developer-tools, networking, operating-systems
- platform: cpp, c, wasm, cross-platform
- tags: coroutines, stackful-coroutines, channels, single-threaded-concurrency, posix, scheduler, amalgamation, no-dependencies, linux, macos

## Member repositories
- tidwall/neco (main) score 63

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:32.001387+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 2026-08-30T04:40:51.761318+00:00, confidence not recorded.
  - readme: https://github.com/tidwall/neco (fetched 2026-08-28T04:04:32.001387+00:00, sha 03f6fff87acb)
- Data as of 2026-08-30T08:39:29.467469+00:00.