I gave your agent access to Firefox - meet Firefox CLI

[Firefox CLI](https://github.com/respawn-llc/firefox-cli) is a CLI interface **that lets your agent control your real Firefox session.** It's a full equivalent of [Agent Browser](https://github.com/vercel-labs/agent-browser) with the same capabilities, but for Firefox - and with a number of improvements. ### Why it's better **First, you install the extension once and for all.** The extension ships right alongside the CLI: install it, grant access, forget about it. Unlike Chrome, where you have to grant connection permissions every half hour and manage debugging sessions - here it's one button and full control. **Second, your agents can now create their own separate windows and request your permission to connect on their own.** In everything else, Firefox CLI mirrors Agent Browser: **token-efficient operation via short IDs**, running arbitrary scripts, keypresses, input emulation, form filling, and full tab and window management of your real session - where you're already logged in. ### Why I built it I used the Comet browser for a long time (on my promo subscription to Perplexity), but it started to let me down. More unnecessary features and ads crept in, it got slower. But the main thing - **using Comet as an actual browser during development is extremely inconvenient**: there's music you can't turn off, a broken onboarding that was never fixed after months of back-and-forth with support, and a poorly functioning CDP. I switched back to Firefox as my main browser, but losing the ability for agents to control my browser was a huge blow to my workflow. **No automation for filling out boring freelance forms, no proper web app testing.** I went looking for alternatives, but nothing like Agent Browser for Firefox simply existed. And here's the result :) --- ## Installation **1. Install the CLI:** ```bash npm install -g firefox-cli ``` **2. Install the Firefox extension:** ```bash firefox-cli setup ``` **3. Install the skill for agents:** _Claude Code_ ```text /plugin marketplace add respawn-llc/claude-plugin-marketplace /plugin install firefox-cli@respawn-tools ``` _Codex_ ```text $skill-installer install https://github.com/respawn-llc/firefox-cli/tree/main/skills/firefox-cli ``` _General_ ```bash npx skills@latest add respawn-llc/firefox-cli ``` --- The project was built by [Builder](https://nek12.dev/blog/builder-open-source-coding-agent-for-engineers) autonomously over 62 hours of continuous work.