# xtaci/kcp-go

A crypto-secure Reliable-UDP library for Golang with FEC support.

Repository: https://github.com/xtaci/kcp-go
Canonical: https://ross.abutalabs.com/products/kcp-go
Language: Go
License: MIT
License Family: permissive
Topics: kcp, forward-error-correction, reed-solomon-codes, reliable-udp-library, symmetric-key-cryptography, automatic-repeat-request
Last push: 2026-05-15T06:23:56+00:00

## Health v2 (maintenance only)
Score: 70/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 82, release rhythm 36, longevity 100
- inputs: {"age_days": 4096, "days_push": 110, "days_rel": 219, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4550, forks 809 (observed 2026-08-28T04:08:53.288530+00:00)

## What it is
kcp-go is a Go library implementing the KCP reliable-UDP protocol, providing smooth, ordered, error-checked, and encrypted stream delivery over UDP with Reed-Solomon FEC support. It offers net.Conn/net.Listener-compatible APIs, making it a drop-in replacement for TCP connections in latency-sensitive applications.

## Use cases
- build low-latency networking for online games
- accelerate network transfers over lossy UDP links
- implement reliable streaming for live broadcasting
- replace TCP with a faster reliable-UDP transport in Go
- add forward error correction to UDP data delivery
- encrypt UDP streams with symmetric-key cryptography

## When to avoid
- you need standard TCP compatibility with non-Go clients
- bandwidth efficiency matters more than latency (KCP trades bandwidth for speed)
- you need an out-of-the-box proxy or tunnel rather than a library

## Facets
- artifact type: library
- maturity: stable
- function: networking, cryptography, compression
- domain: networking, developer-tools, gaming-tools
- platform: go, windows, cross-platform
- tags: kcp, reliable-udp, forward-error-correction, reed-solomon, latency-sensitive, net-conn-compatible, udp, real-time, linux, macos

## Member repositories
- xtaci/kcp-go (main) score 70

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:53.288530+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 2026-08-29T18:20:05.336238+00:00, confidence not recorded.
  - readme: https://github.com/xtaci/kcp-go (fetched 2026-08-28T04:08:53.288530+00:00, sha babcc216ffac)
- Data as of 2026-08-30T08:39:29.467469+00:00.