# OpenSnell: reconstructing the Snell v4/v5 proxy protocol

> OpenSnell reconstructs the Snell v4/v5 proxy protocol in a Go client and server. It handles TCP CONNECT, UDP over TCP, HTTP and TLS obfuscation, with v5 QUIC proxy mode on the server. The author reports interoperability against Surge snell-server v5.0.1.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/missuo/opensnell>
- Primary source: <https://github.com/missuo/opensnell/blob/49a61f2f6cd94834a0e6256f30ceafa78127219c/README.md>
- Catalog page: <https://awesomerea.org/resources/opensnell-case/>
- Record JSON: <https://awesomerea.org/resources/opensnell-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/opensnell-case/index.md)

## Requirements & limits

- **Prerequisites:** Go 1.24 is specified by go.mod.
- **Limits:** Snell v5 QUIC proxy mode is server-side only.
- **Scope:** The repository publishes v4/v5 code; its documented v6 implementation is closed source.
- **License:** GPL-3.0 license.

## Primary sources

1. <https://github.com/missuo/opensnell/blob/49a61f2f6cd94834a0e6256f30ceafa78127219c/README.md>
2. <https://github.com/missuo/opensnell/blob/49a61f2f6cd94834a0e6256f30ceafa78127219c/SNELL_V6.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.