# Vibe-engineering a Firefox add-on: Container Traffic Control

DevFeed: [Vibe-engineering a Firefox add-on: Container Traffic Control](<https://devfeed.tech/articles/vibe-engineering-a-firefox-add-on-container-traffic-control-25235.md>)

Original publisher: [Read original article](<https://kau.sh/blog/container-traffic-control/>)

Author: Kaushik Gopal

Published: 2025-09-29T02:31:35Z

Content type: opinion

Language: en

Sources: [Kaushik Gopal's Site](<https://devfeed.tech/sources/kaushik-gopal-s-site.md>)

Topics: [Browser Extension](<https://devfeed.tech/topics/browser-extension.md>), [Firefox](<https://devfeed.tech/topics/firefox.md>), [JavaScript](<https://devfeed.tech/topics/javascript.md>), [Code review](<https://devfeed.tech/topics/code-review.md>), [GitHub](<https://devfeed.tech/topics/github.md>), [Software](<https://devfeed.tech/topics/software.md>)

Tags: [code-review](<https://devfeed.tech/tags/code-review.md>), [extension](<https://devfeed.tech/tags/extension.md>), [firefox](<https://devfeed.tech/tags/firefox.md>), [github](<https://devfeed.tech/tags/github.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [software](<https://devfeed.tech/tags/software.md>)

## AI overview

An experiment in building the Container Traffic Control Firefox add-on entirely through agent-assisted development, without manually editing JavaScript. The author argues that careful instructions, prompting, pruning, testing, organization, logging, comments, and code review can produce a readable and maintainable small codebase.

## Source excerpt

I wanted to test a simple claim: you can ship maintainable software by vibe-engineering end to end. I set strict constraints: New platform (I haven't built a browser extension/add-on) Language I'm no longer proficient in (JavaScript) Zero manual code editing In about a day1 I had a working Firefox add-on I could submit for review. The code meets my bar for readability and long-term change. Even the icon came from an image model.2 Introducing Container Traffic Control. Install and source - Install: Firefox add-on listing - Code: github.com/kaushikgopal/ff-container-traffic-control On the vibe-engineering process ## It's in vogue to share horror stories of decimated vibe-coded repos.3 But I'm convinced that with the right fundamentals, you can vibe-engineer4 a codebase you'd comfortably hand to another engineer. This was my experiment to vet my feelings on the subject. Granted, this was a small and arguably very simple repository, but I've also seen success with moderately larger codebases personally. It comes down to scrupulous pruning: updating system instructions, diligent prompting, and code review. I plan to write much more about this later, but let's talk about some of the mechanics of how it went: I didn't write a single line of JavaScript by hand. When I needed changes, better structure, reusable patterns, small refactors -- I asked the agent. The goal throughout was simple: keep the codebase readable and maintainable. It now has a lot of the things we consider important for a decent codebase: Tests (for the important parts) Well-organized code Clear, useful logging Code comments (uses a style called space-shuttle style programming, which I think is increasingly valuable with vibe-engineering) The best part: most of this came together over two days.5 Some example pull requests from the repository with the exact prompt I used and the plan that was generated: Here's the very first prompt I used to generate the guts of the code: # Role/Persona: - you are an expert