APXY is a local network proxy and debugging tool that captures, inspects, mocks, replays, and diffs HTTP/HTTPS traffic. It is built for developers and AI coding agents with a CLI-first workflow and an optional Web UI.

How is APXY different from Charles Proxy or mitmproxy?

APXY is purpose-built for the modern developer workflow including AI coding agents. It provides structured output (TOON format) that AI agents can reason over, a CLI-first API for scripting and automation, and first-class support for CI/CD, Docker, and headless environments. Unlike Charles Proxy, APXY requires no GUI and unlike mitmproxy, it includes API mocking with scripting and a built-in Web UI.

Does APXY work with AI coding agents like Claude Code and Cursor?

Yes. APXY has dedicated integrations for Claude Code, Cursor, GitHub Copilot, and OpenAI Codex. It returns compact, structured network traffic so AI coding agents can reason over real HTTP requests and responses instead of screenshots or raw HAR files.

APXY has a free tier that lets you capture traffic and explore the Web UI with no account or credit card required. Paid one-time licenses (Pro at $59, Personal at $79) unlock unlimited traffic history, API diagnosis, scripting, breakpoints, network simulation, and multi-device access.

Does APXY work in CI/CD pipelines and Docker?

Yes. APXY runs headlessly and works in local development, CI pipelines, SSH sessions, Docker containers, and background scripts. The core CLI workflow stays the same across all environments.

What operating systems does APXY support?

APXY supports macOS, Linux, and Windows.

APXY vs Fiddler

Balanced verdict

Choose Fiddler Classic if your team is Windows-only and .NET-focused with no need to leave the desktop. Choose Fiddler Everywhere if you want a polished GUI on any platform and are comfortable with a per-seat subscription. Choose APXY if you need CLI-first operation, headless CI support, AI agent compatibility, replay and diff workflows, or a one-time license.

Editorial take

Fiddler has two products: Fiddler Classic — the original free Windows-only proxy that .NET developers have used for years — and Fiddler Everywhere, a cross-platform rewrite with a monthly subscription. APXY competes differently: a CLI-first local proxy that runs the same way on macOS, Linux, and Windows, works headlessly in CI and Docker, produces structured output for AI coding agents, and costs a one-time $59 for Pro. If your team is deeply embedded in the Windows and .NET ecosystem and already knows Fiddler Classic, switching has a real cost. If you are building on any other stack or need the debugging workflow to travel beyond a desktop, APXY is the stronger choice.

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Best for Fiddler

Windows/.NET desktop inspection

Best for APXY

CLI, CI, Linux, AI agents

Biggest difference

Headless support and agent-ready output

Comparison Matrix

How APXY compares to Fiddler

This is the fastest way to understand the tradeoff. The competitor still has real strengths, but APXY pulls ahead when the debugging workflow needs to be reusable, shareable, and easier to operationalize across a team.

Criterion	APXY	Fiddler	Take
Platform support	macOS, Linux, and Windows with the same CLI and Web UI workflow everywhere.	Fiddler Classic is Windows-only. Fiddler Everywhere is cross-platform but subscription-based.	APXY edge
Headless / CI operation	Runs headlessly in Docker, GitHub Actions, and SSH sessions — no GUI required.	Neither Fiddler product is designed for headless or CI use. Both require a desktop environment.	APXY edge
CLI-first workflow	Fully scriptable CLI for capture, filter, mock, replay, export, and diff.	GUI-centric products. Neither is built around a terminal workflow.	APXY edge
AI coding agent support	TOON format delivers compact, structured traffic data agents can reason over directly.	No structured agent output. Requires manual export and translation to use with AI tools.	APXY edge
Windows / .NET familiarity	Works on Windows, but not purpose-built for the .NET debugging ecosystem.	Fiddler Classic has deep roots in the Windows and .NET developer community.	Competitor edge
Request replay and diff	Replay captured requests after a fix and diff before/after responses — core to the workflow.	Available in Fiddler Everywhere but not a primary part of the product loop.	APXY edge
Pricing	Free tier with no account. Pro is $59 one-time. No subscription.	Fiddler Classic is free but Windows-only. Fiddler Everywhere requires a per-seat monthly subscription.	APXY edge
Mock and scripting	API mocking with JavaScript scripting, breakpoints, and unlimited mock rules on Pro.	FiddlerScript and AutoResponder available but require learning a proprietary scripting model.	APXY edge

Choose APXY If

You want the debugging loop to be repeatable

APXY's CLI-first design runs identically on macOS, Linux, and Windows — including headlessly in CI and Docker.
Structured TOON output lets AI coding agents like Claude Code and Cursor reason directly over captured traffic.
Replay and diff are first-class features: prove your fix worked without manually reproducing the failure.

Choose Fiddler If

The workflow is narrower and more specialized

Fiddler Classic is deeply familiar to Windows and .NET developers with years of muscle memory.
Free for classic Windows debugging — no cost to inspect traffic on a Windows machine.
Fiddler Everywhere provides a cross-platform GUI for teams that want a polished visual tool on any OS.

Section 1

Fiddler Classic still has a home in Windows and .NET teams

Fiddler Classic earned genuine loyalty because it arrived early and solved a real problem for Windows developers. For .NET teams that have been using it for years, the interface is familiar, the workflows are internalized, and switching carries real friction costs. Fiddler Classic is also free, which matters when budget is tight and the use case is simple desktop inspection on Windows.

That is worth being honest about. If your team is Windows-only, the code is .NET, and the debugging workflow stays on a single developer's machine, Fiddler Classic still works for that job. APXY is not trying to win by being more familiar. It wins by covering more ground.

Free for classic Windows desktop traffic inspection

Familiar to .NET developers who have used it for years

Good for simple request inspection on a single Windows machine

Section 2

APXY is the stronger choice the moment you leave the Windows desktop

Fiddler Classic does not run on Linux. It does not run headlessly. It cannot operate inside a Docker container, a GitHub Actions workflow, or an SSH session. Fiddler Everywhere addresses the cross-platform gap but at the cost of a per-seat subscription and a heavier GUI product that still does not solve the headless or CI use case.

APXY was designed to work the same way in every environment. The CLI runs in a terminal on any OS, produces the same output whether you are debugging locally or in a CI pipeline, and hands structured traffic evidence to AI coding agents that can reason about it directly. That design choice is the biggest reason developers on modern stacks choose APXY over Fiddler.

Full Linux and macOS support with the same CLI workflow as Windows

Headless operation in Docker, GitHub Actions, and SSH with no GUI dependency

AI agent-compatible structured output without manual export steps

Section 3

One-time pricing and a modern debugging loop close the case

Fiddler Everywhere is a subscription product. At typical per-seat pricing, a small team pays more in a year than APXY Pro costs once. APXY's $59 one-time Pro license includes one year of updates and covers one device. The Personal license at $79 covers two devices. No recurring charges.

Beyond pricing, the post-capture debugging loop is more complete in APXY. Replaying a request after a fix, diffing the before and after response, and exporting structured artifacts for team handoff are built into the product. These are the steps that turn a proxy session into repeatable engineering evidence — and they are what separates APXY from tools that stop at inspection.

Migration Path

How to move without breaking the current workflow

1.Install APXY alongside Fiddler — both can run on Windows during evaluation.
2.Use APXY first for any workflow that touches Linux, CI, Docker, or AI coding agents.
3.Replace Fiddler Everywhere with APXY Pro to eliminate the per-seat subscription.
4.Keep Fiddler Classic only if the team has a genuine Windows/.NET-only use case with no plans to expand.

Final decision lens

Use this checklist to decide faster

Choose Fiddler Classic if the team is Windows-only, .NET-focused, and the workflow is purely manual desktop inspection.

Choose APXY over Fiddler Everywhere if you are paying a subscription and want a one-time license instead.

Choose APXY if any part of your workflow runs on Linux, in CI, or in Docker.

Choose APXY if you use AI coding agents like Claude Code, Cursor, or Codex.

Choose APXY if replay, diff, and reproducible debugging artifacts matter to your team.

FAQ

Frequently asked questions about APXY vs Fiddler

Does APXY run on Windows like Fiddler?

Yes. APXY runs on macOS, Linux, and Windows with the same CLI and browser-based Web UI on all platforms. The workflow is identical regardless of OS.

Is Fiddler Classic still worth using in 2026?

For Windows-only .NET teams doing simple manual inspection, Fiddler Classic remains functional and free. For any other use case — Linux, CI, headless, AI agents, or a modern cross-platform workflow — APXY is a stronger fit.

How does APXY pricing compare to Fiddler Everywhere?

Fiddler Everywhere uses a per-seat subscription model. APXY Pro is a $59 one-time license per device with one year of updates. For most individual developers and small teams, APXY is cheaper within the first year and significantly cheaper over two or more years.

Can APXY replace FiddlerScript for mock and scripting workflows?

Yes. APXY includes JavaScript-based API mocking with unlimited mock rules on Pro, breakpoints for pausing and modifying requests, and a full scripting CLI. The model is more standard and easier to maintain than FiddlerScript's proprietary approach.

Does APXY work in GitHub Actions or Docker like a CI proxy?

Yes. APXY is designed to run headlessly in CI environments including GitHub Actions, Docker containers, and SSH sessions. Fiddler does not support headless operation — it requires a desktop GUI environment.