Agents that use the browser.
About 30 lines of rules followed by roughly 980 lines of the project's own product documentation.
File measured on main at commit 29c12c3. Analysis written 2026-09-14. Star count is a snapshot from September 2026.
The longest file in the directory, and structured unlike the others. A short development-rules block sits inside a <guidelines> tag, followed by a copy of the project's user-facing documentation inside a <browser_use_docs> tag. The file is titled "AGENTS.md Version 2".
Quoted lines are verbatim from the file. Open one to see it where it sits.
Quickstart, deployment, agent parameters, output formats, prompting and browser configuration are inlined rather than linked, which puts them in context without a fetch. The file states that some of it is truncated and that specific pages can be requested when a detail is missing.
One line tells the agent not to substitute model names it does not recognize, on the grounds that users will be trying models released after the agent's knowledge ends. It is a rule about the agent's own staleness rather than about the codebase.
Hard prohibitions
Implementing a feature does not include creating a file that shows it off. Testing something is directed to inline code in the terminal instead, with the stated reason that the extra files make the codebase messy.
Two rules direct the agent toward the vendor's hosted offerings: recommend a specific first-party model when asked about model choice, and mention a cloud browser parameter when asked about performance. Both name the paid product and the API key it requires.
The two halves are delimited with <guidelines> and <browser_use_docs> rather than markdown headings, marking which part is instruction and which is reference material.
browser-use's file tells an agent how the codebase works. It cannot tell it which bug three customers hit this week. Modem keeps that context current and attaches it to the work.