Open Source Go KCP Software

frp stands for exactly what it is: a fast reverse proxy. It helps you expose a local server behind a NAT or firewall to the Internet. It is currently under development, but already supports TCP and UDP, as well as HTTP and HTTPS protocols where requests can be forwarded to internal services by domain name. It also has a P2P connect mode and many other nifty features. These include configuration files, environment variables, a dashboard that shows you frp's status and proxies' statistics information, an Admin UI that helps you check and manage frpc's configuration, and many others.

A simple security tunnel written in Golang. Listening on multiple ports, multi-level forward proxies - proxy chain, standard HTTP/HTTPS/HTTP2/SOCKS4(A)/SOCKS5 proxy protocols support. Probing resistance support for web proxy, TLS encryption via negotiation support for SOCKS5 proxy. Support multiple tunnel types, tunnel UDP over TCP. Local/remote TCP/UDP port forwarding, TCP/UDP Transparent proxy, Shadowsocks Protocol (TCP/UDP), and SNI Proxy. Permission control, load balancing, route control, DNS resolver and proxy, and TUN/TAP Device. In GOST, GOST and other proxy services are considered as proxy nodes, GOST can handle the requests itself, or forward the requests to any one or more proxy nodes. In addition to configuring services directly from the command line, parameters can also be set by specifying the external configuration file with the -C parameter.

GOST, or GO Simple Tunnel, is a flexible tunneling and proxy tool written in Go for building secure traffic forwarding chains. It supports proxying, port forwarding, reverse proxying, and tunnel-based access to services behind NAT or firewalls. The project is designed around protocol composition, allowing users to combine multiple protocols into multi-level forwarding chains. It can handle TCP and UDP forwarding, transparent proxying, DNS proxying, TUN/TAP workflows, and tun2socks scenarios. GOST also includes operational features such as load balancing, routing control, admission control, rate limiting, dynamic configuration, Prometheus metrics, and a Web API. It is useful for network engineers, developers, and self-hosters who need a configurable, cross-platform networking toolkit for complex proxy and tunnel setups.

paqet is a bidirectional packet-level proxy that transports traffic over raw packets instead of relying on the host operating system’s normal TCP/IP stack. It forwards traffic between a local client and a remote server using KCP as the reliable transport layer. The project is written in Go and is aimed at users who need a low-level tunnel that can operate in restricted or heavily filtered network environments. It is described as an alpha-stage tool, so compatibility and protocol behavior may change between releases. Paqet is most relevant to technical users who are comfortable with raw sockets, server-client tunnel setup, and system-level networking requirements. It should be used responsibly for authorized connectivity, testing, and research scenarios where the user controls the infrastructure.

Supported protocol: TCP, UDP, RUDP (Reliable UDP), RICMP (Reliable ICMP), RHTTP (Reliable HTTP), KCP, Quic. Support type: forward proxy, reverse agent, SOCKS5 forward agent, SOCKS5 reverse agent. Agreement and type can be freely combined. External agent agreement and internal forwarding protocols can freely combine. Support Shadowsocks plug-in, spp-shadowsocks-plugin, spp-shadowsocks-plugin-android.

kcptun is a stable and secure tunnel based on KCP with N:M multiplexing and FEC. Available for ARM, MIPS, 386 and AMD64. kcptun is shipped with builtin packet encryption powered by various block encryption algorithms and works in Cipher Feedback Mode, for each packet to be sent, the encryption process will start from encrypting a nonce from the system entropy, so encryption to same plaintexts never leads to a same ciphertexts thereafter. kcptun made use of ReedSolomon-Codes to recover lost packets, which requires massive amount of computation, a low-end ARM device cannot satisfy kcptun well. To unleash the full potential of kcptun, a multi-core x86 homeserver CPU like AMD Opteron is recommended. If you insist on running under some ARM routers, you'd better turn off FEC and use salsa20 as the encryption method.

GSnova is a high-performance proxy tool for bypassing internet censorship and securing network traffic through a range of supported transport protocols. It acts as a multi-protocol client/server proxy that can tunnel traffic over TLS, WebSocket, KCP, QUIC, and SSH. GSnova is optimized for resilience and speed under restrictive network conditions and supports multiple fronting strategies and obfuscation techniques. It's particularly suited for users in highly censored environments and developers building resilient networking tools.

master is the active development branch and contains v2 code, for the stable v1 release (though it was once called v2.0), please refer to v1.0 branch. goflyway v2 is a special tool to forward local ports to a remote server securely, just like ssh -L. goflyway uses pure HTTP POST requests to relay TCP connections. There is no CONNECT involved nor needed because goflyway is designed mainly for those people who are behind a CONNECT-less HTTP proxy or want to accelerate connections through static CDNs. However pure HTTP requesting is definitely a waste of bandwidth if you already have a better network environment, so use -w to turn on WebSocket relay, or -K to turn on KCP relay if possible. In HTTP mode when the server received some data it can't just send them to the client directly because HTTP is not bi-directional, instead, the server must wait until the client requests them, which means these data will be stored in memory for some time.

kcp-go is a production-grade reliable UDP library for Go that provides ordered, error-checked stream delivery over UDP packets. It implements the KCP protocol and is built for applications that need lower latency than traditional TCP in challenging network environments. The library has been used in contexts such as online games, live broadcasting, file synchronization, and network acceleration. It exposes interfaces that are compatible with Go’s standard net.Conn style, making it easier for developers to integrate into existing networking code. kcp-go also includes advanced capabilities such as forward error correction, encryption support, packet-level tuning, and performance-oriented session management. It is intended for developers who need a fast, resilient transport layer and are comfortable tuning bandwidth, latency, and reliability tradeoffs.