Quena

Quena is a free and open-source HTTP(S) debugging proxy for macOS, Windows and Linux. It sits between your applications and the servers they talk to, so you can capture, inspect, modify, replay and simulate network traffic - in the spirit of tools like Fiddler or Charles, but cross-platform and with a built-in diagnostics engine.

Capture & inspect: HTTP/1.1, HTTP/2, HTTPS (with local certificate authority), WebSocket and Server-Sent Events. Inspect headers, bodies, cookies and authentication, including specialised views such as a SOAP inspector.

Diagnostics: an automatic analysis engine scans thousands of sessions and reports prioritised findings (critical, warning, info) such as N+1 request patterns, authentication loops, latency-sensitive request chains or missing compression. Statistics and timing waterfalls help to find bottlenecks.

Change & replay: mock rules, request/response breakpoints and tampering, plus a composer with cURL import to craft and resend requests.

Enterprise ready: automatic NTLM, Kerberos and Basic authentication, mTLS client certificates and bandwidth/network throttling simulation.

Extensible: sandboxed JavaScript rules (QuickJS) with hot reload, and WebAssembly-based plugins for custom inspectors and decoders.

CI integration: the quena-cli command-line tool (also available as a Docker image) turns diagnostics into quality gates for GitHub Actions, GitLab CI or Jenkins pipelines.

Built with Rust and Tauri 2 (React/TypeScript UI), released under the Apache License 2.0.