# websocat — Command-Line WebSocket Client Like Netcat

> websocat is a Rust-based CLI tool for connecting to WebSockets, acting as a netcat or curl equivalent for the ws:// protocol with advanced piping and proxying features.

## Install

Save as a script file and run:

# websocat — Command-Line WebSocket Client Like Netcat

## Quick Use
```bash
cargo install websocat
# Connect to a WebSocket server
websocat ws://echo.websocket.org
# Pipe stdin to WebSocket and print responses
echo "hello" | websocat ws://echo.websocket.org
```

## Introduction
websocat bridges the gap between traditional Unix command-line tools and WebSocket-based services. It provides a socat-like interface for bidirectional communication over WebSocket connections, making it straightforward to test, debug, and script interactions with WebSocket APIs.

## What websocat Does
- Connects to WebSocket servers as a client or listens as a server
- Pipes data between stdin/stdout and WebSocket connections
- Supports TLS for secure wss:// connections
- Provides proxy and relay modes for bridging protocols
- Handles both text and binary WebSocket frames

## Architecture Overview
websocat is built in Rust using the tokio async runtime and the tungstenite WebSocket library. It models connections as a pair of read/write halves, allowing flexible composition of data sources and sinks. The tool supports a specifier syntax that lets you chain connections, for example piping a TCP listener through a WebSocket connection to another endpoint.

## Self-Hosting & Configuration
- Install via `cargo install websocat` or download prebuilt binaries
- No configuration file needed; all options are passed as command-line flags
- Use `--binary` flag for binary frame mode instead of text
- Set custom headers with `-H "Header: value"` for authentication
- Enable autoreconnect with `--autoreconnect` for resilient connections

## Key Features
- Single static binary with no runtime dependencies
- Supports Unix sockets, TCP, UDP, and stdio as endpoints
- Built-in WebSocket server mode for quick prototyping
- Message-based and line-based framing modes
- Composable address specifiers for complex routing

## Comparison with Similar Tools
- **wscat** — Node.js WebSocket client, simpler but requires a Node runtime
- **curl** — Supports WebSocket since v7.86 but with limited interactivity
- **socat** — General-purpose relay tool, no native WebSocket support
- **webwrap** — Lightweight WebSocket proxy, less feature-rich

## FAQ
**Q: Can websocat act as a WebSocket server?**
A: Yes. Use `websocat -s 8080` to start a simple WebSocket server on port 8080.

**Q: How do I send binary data?**
A: Use the `--binary` flag and pipe binary data through stdin. websocat will send it as binary WebSocket frames.

**Q: Does it support authentication?**
A: Yes. Pass custom headers with `-H` flags, including Authorization headers for token-based auth.

**Q: Can I use websocat for load testing?**
A: websocat is designed for single-connection debugging and scripting, not for high-concurrency load testing.

## Sources
- https://github.com/vi/websocat
- https://github.com/vi/websocat/blob/master/doc.md

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Source: https://tokrepo.com/en/workflows/asset-35ac93b4
Author: Script Depot