Curl 8.22.0 Adds WebSocket Support for Real-Time Data Transfers 🔗
New WS/WSS protocol handling expands curl’s utility beyond traditional HTTP and file transfers
The latest release of curl, version 8.22.
0, introduces native support for WebSocket (WS and WSS) protocols, enabling direct real-time bidirectional communication from the command line. This update allows developers to test, debug, and interact with WebSocket servers using familiar curl syntax—such as curl ws://example.com/socket—without relying on external tools or custom scripts.
Beyond WebSockets, curl continues to unify data transfer across 25+ protocols including HTTP/3, SFTP, SMB, and MQTT, all powered by the portable libcurl library. Its single-binary design and MIT-like licensing make it ideal for embedded systems, CI/CD pipelines, and automation workflows where minimal dependencies and broad protocol coverage are essential. The project’s C implementation ensures high performance and low-level control, while maintaining backward compatibility across decades of use.
Despite its maturity, curl remains actively maintained, with the latest commit just days ago and a steady stream of protocol refinements. The addition of WS/WSS reflects growing demand for lightweight, scriptable tools in real-time web applications and IoT edge computing.
The catch: While curl’s WebSocket support enables basic client interactions, it lacks advanced features like subprotocol negotiation, per-message compression control, or binary frame handling found in full-featured WebSocket libraries, limiting its use in complex application-level scenarios.
Why this leads today curl remains essential infrastructure, with ongoing maintenance ensuring reliability in developer workflows where silent failures can disrupt critical automation and API interactions.
- Developers testing WebSocket APIs in CI/CD pipelines
- Automation scripts transferring data over SFTP and SMB
- IoT devices exchanging telemetry via MQTT over constrained networks
Source: curl/curl — based on the README and release notes.