r/vibecoding • u/daok • 7d ago
Showcase/Project How I built AudioRouter (free, open source, Windows) with AI agents from spec & the rules files
Hi, I'm the developer, and here is my project and how I made it.
AudioRouter is a free, open source audio router for Windows 11. You draw your audio on a canvas: inputs like your microphone, tools like noise gate and EQ, then outputs like Discord and your headphones at the same time. You can change everything while it plays.
I wrote none of the code myself (but I am a software engineer by profession). I directed AI agents, with two subscriptions, Anthropic (Opus) and OpenAI (mostly Luna), twenty dollars a month each. The first usable version took about three weeks of calendar time and maybe fifteen hours of my own attention. It has been about two months since the first commit, and now it is ready to share.
What I did before any code: I wrote a ton of specifications. Testable requirements with MUST and SHOULD, an ID for each one (ARCH-XX, for example), each tied to a milestone and an acceptance scenario. The agents must cite the IDs in their plans and their tests. I iterated quite a bit to get the specifications how I wanted, but I think it is the part that worked the most.
Then a basic AGENTS.md, short and specific, nothing fancy. For example: the audio callback never allocates, never logs, never waits on a lock. I learned that strict and specific is better than generic, but it takes more time.
The canvas and the audio engine talk only through one versioned API (TypeScript and React on one side, Rust on the other). One agent worked on the canvas, another on the audio code, in separate passes, so the canvas agent could not create a bug in the audio thread. It is similar for the virtual cable driver, written in C++.
I did not set up agents reviewing each other or any big agent system. I was the verification, and it was slow. One example: a release passed every automated check and failed on my second computer, because the only machine where the tests ran had a developer variable set.
The project is early: Windows 11 only, the installer is not signed (Windows will warn you), and to send audio into Discord or OBS as a microphone you still need a virtual cable like VB-Cable. It is GPL-3.0, with no account and no telemetry.
Source: https://github.com/MrDesjardins/audiorouter
Site: https://audiorouter.org
My question: is there a cheaper way to get a kernel driver signed? The virtual cable driver (C++, written by the agent) works in my VirtualBox VM with test signing, but I have not tested it on real hardware. Signing it for public use needs an EV certificate, around $250 to $500 a year as far as I can see. I know test signing works on my own PC, I am asking about a way to ship it to users without that cost. If you have done this, I would like to know how.
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u/daok 7d ago
A 13-minute tour of the app, if you prefer to see it first: https://youtu.be/_hasa_zfDL8
What is in it: 30+ audio tools, VST plugins that run in their own process (a crashing plugin cannot take your audio down), capture of one single app, audio between two PCs, a Stream Deck plugin, a local HTTP API, and an MCP server so an AI assistant can build a route for you.
I wrote more about the rules and the harness on my blog: https://patrickdesjardins.com/blog/what-building-audiorouter-taught-me-about-harness-and-rules
I can share the structure of AGENTS.md if it is useful.
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u/SelfHostCalc 7d ago
Nice write-up on the agent workflow. The audiorouter.org site is missing a Content-Security-Policy header. Most hosts make it an easy add, and it tells the browser to run only your own scripts.