agent-browser

agent-browser (vercel-labs) is the swarm's browser-automation CLI. It drives a headless Chromium over CDP and returns accessibility-tree snapshots with compact @eN refs. Use it for any browser task: verify a UI change, take a screenshot, walk a page, fill a form, extract page text, reproduce a frontend bug, or attach UI evidence to a PR, issue, Linear comment, or Slack thread.

Do not use qa-use. It is not installed in the worker image any more.

Step 0: check that the CLI is present

The full worker image (agent-swarm-worker:latest) ships agent-browser and a headless Chromium. The slim image (:slim) has neither. The first command of any browser work is:

command -v agent-browser

If it prints nothing, you are on the slim image. Say so in your progress report ("agent-browser is not available on this worker image") and fall back to manual QA: write the exact steps a human should run and mark the browser test cases as Blocked, not failed. Do not install a browser or the CLI yourself.

Step 1: load the version-matched guide

The CLI bundles its own usage guide. Load it once per task before the first browser command. Do not guess flags from memory.