foxlend — lend one login to an AI agent Pooria מאת

An AI agent in your browser can use every site that you are logged in to. foxlend gives it one.

Who it is for: people and developers who run an AI agent in Firefox and want to limit what it can reach.

What it does

• Makes a new container named "Agent · <site>", copies the cookies of one site into it, and opens the agent's tab there. Your own tabs stay logged in.
• Blocks each request from that container to a host that is not the lent site or on your allow list, and shows a live log of blocked requests.
• Sets a scope (read, fill, submit or pay) and a time limit for each loan. A foxgate grant with the same scope covers the same hosts.
• When you revoke the loan, or when its time is up, closes the agent's tabs and removes the container with its cookies and site data.
• Can hide the agent's tab, if you tick "Hide the agent tab".

A change to Firefox settings while a loan is active: foxlend turns off WebRTC and network prediction for all of Firefox, so a page in the container cannot send data around the block. This also affects your own tabs: no page can start a WebRTC call, for example a video call, until the last loan ends. foxlend turns the settings back when the last loan ends. This happens only when you lend a login.

What leaves your computer: nothing. foxlend has no server and makes no network requests of its own. Loans and the blocked log stay in this browser.

Permissions

• Containers, cookies, tabs and hidden tabs: make the loan container, copy one site's cookies into it, and open, hide and close the agent's tabs.
• Access to all websites, web requests and proxy: block requests from the loan container to hosts outside the loan. foxlend cancels a blocked request, or sends it to a local proxy address where nothing listens (127.0.0.1, port 9).
• Privacy: turn off WebRTC and network prediction while a loan is active.
• Browsing data: remove the container's site data on revoke.
• Public suffix list: find the site of a host.
• Storage and alarms: keep the loans and end each one when its time is up.

The source code is MIT licensed.