AI Already Did It › Internet & Networking › Network Tools

Luthier — Web Debugging Proxy

A Fiddler Classic–style web debugging proxy for Linux. Capture, inspect, edit, replay and mock HTTP/HTTPS traffic from a native desktop app.

Screenshots

Description

Luthier

Luthier is a desktop web debugging proxy for Linux, modelled on Fiddler Classic. It sits between your applications and the network, records every HTTP and HTTPS session, and lets you inspect, edit, replay, mock and filter the traffic from a native Qt window — the tool Linux has been missing since Fiddler Classic stayed Windows-only.

It installs as a single self-contained package. No system Python, no PySide6, no pip — the app bundles its own runtime under /opt/luthier.

Features

• Capture everything. HTTP and HTTPS from any app configured to use the proxy, with a local root certificate for HTTPS decryption, WebSocket frame capture, and automatic gzip / deflate / brotli / zstd decoding.
• Inspect deeply. Request and response inspectors for Headers, TextView, SyntaxView (with highlighting and pretty-printing), WebForms, HexView, Auth (Basic, Bearer/JWT, Digest), Cookies, Caching, Raw, JSON, XML, ImageView, WebView and WebSocket.
• Edit and replay. Set breakpoints before a request or after a response, change anything while it's paused, and reissue requests. Build requests by hand in the Composer, or paste a cURL command.
• Mock and rewrite. The AutoResponder returns local files, canned responses, redirects or delays for matching URLs. Rewrite headers and bodies, block resources, and simulate slow connections.
• Automate with Python. Write rules in Python (the equivalent of FiddlerScript) with hooks for every request and response.
• Understand performance. A Statistics tab with a full timing breakdown and a Timeline waterfall showing DNS, connect, TLS, first byte and connection reuse.
• Filter the noise. Hide by host, process, status code, content type or size, and highlight what matters.
• QuickExec command bar, session marking and comments, and a searchable session list with Fiddler-style icons and colour coding.
• Save and share. Load and save Fiddler .saz archives, plus HAR import/export and cURL export.
• One-click certificate trust for Firefox and Chrome, so HTTPS decryption just works.
• Light and dark themes, and it fits any screen size.

Getting started

Install the .deb (Debian/Ubuntu/Mint) or .rpm (Fedora/RHEL/openSUSE), launch Luthier, and press F12 to start capturing. To decrypt HTTPS, enable it in Tools → Options and let Luthier install its root certificate into your browsers.

Notes

Built with Python, PySide6 (Qt) and cryptography. HTTP/2 and HTTP/3 are not supported (clients negotiate down to HTTP/1.1), matching Fiddler Classic. Not affiliated with Progress or Telerik. Released under the MIT License.

Downloads

• luthier_0.1.0_amd64.deb — Linux, 54.6 MB
• web_debugging_proxy_tool.tar.gz — Source, 1.4 MB

Original prompt(s)

Prompt 1

The prompt that created the app:

Web Debugging Proxy Tool:

  Cerate a Debugging Proxy Tool application

- Research Fiddler Classic before implementing any code

- It should be desktop application of course

The follow-up prompts that refined it, in order:

1. when I run from pycharm it breaks my internet connection !

2. the issue still exists, firefox says: Software is Preventing Firefox From
   Safely Connecting to This Site ... HTTP Strict Transport Security (HSTS) ...

3. we have some serious issues. When I testing, the windows weight turned out
   too long. So Do serious Q/A testing before posting the application to
   production

4. create a .deb and .rpm installation file

5. add MIT licence file since I am uploading the app to aialreadydidit.com

Tags: api-testing,, developer-tools, http, https, linux, mitm, network-debugging, proxy, traffic-inspector, web-debugging-proxy

Open in AI Already Did It