microtunnel

Self-hosted HTTPS tunnels made simple — using Go, Caddy, and Cloudflare.

• One lightweight Go binary.
• Automatic HTTPS with wildcard certificates.
• WebSocket-based tunneling (no raw TCP needed).
• Fully self-hosted: your domain, your rules.

Read the full story here →

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Why microtunnel?

Most tunneling tools either require paid plans, rely on proprietary infrastructure, or need complex setups. microtunnel is a self-hosted alternative that gives you HTTPS tunnels using just Go, WebSockets, and Caddy — no third-party services required.

• No paid plans
• No vendor lock-in
• No opaque black boxes

Just one Go binary + Caddy with automatic TLS = your own public HTTPS tunnel.

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Features

• 🔐 Secure WebSocket-based tunneling
• 🔒 Automatic Let's Encrypt TLS (via Cloudflare DNS)
• 📡 Multiplexing multiple HTTP streams over one WebSocket with yamux
• 🖊️ Simple, structured logs (thanks, Logrus)
• 🌐 Designed for side-projects, demos, webhook testing

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Quick Start

Server Setup

First, prepare your environment variables:

export TUNNEL_SERVER_DOMAIN_NAME=tunnel.example.com
export CADDY_PROXY_PORT=3000
export CF_API_TOKEN=your_cloudflare_token

Build and run the server:

go run main.go --port 3000 --base-domain-name=tunnel.example.com

Caddy needs to be set up separately for wildcard HTTPS. See full guide in the article.

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Client Usage

Tunnel your local app (e.g., running on localhost:8080):

go run main.go --server-url=wss://tunnel.example.com/tunnel --port 8080

You'll get a URL like:

https://ab12cd34.tunnel.example.com

Open it. Magic.

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How It Works

• Clients connect to /tunnel via secure WebSocket.
• Server assigns a random 8-character subdomain.
• Caddy handles automatic TLS certificates.
• Yamux multiplexes multiple HTTP requests over a single WebSocket.
• HTTP hijacking enables raw streaming of HTTP traffic without re-encoding.

For a deeper technical dive, check the full article.

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Requirements

• A domain (e.g., example.com) with Cloudflare managing DNS.
• A public VM (free Oracle/AWS/anything).
• Go (for building the binary).
• Caddy (with Cloudflare DNS plugin).

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Future Improvements

• Token-based tunnel authentication
• gRPC transport support
• Prometheus metrics for tunnel traffic

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Demo

Tunnel established

Incoming request to server

Accessing local app via HTTPS

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License

MIT. Do whatever you want. Stars are appreciated

GitHub Repository →