name: agent-browser

description: |

Browser automation CLI for AI agents. Use when the user needs to inspect,

test, or automate browser behavior: navigating pages, filling forms,

clicking buttons, taking screenshots, extracting page data, testing web

apps, dogfooding Open Design previews, QA, bug hunts, or reviewing app

quality. Prefer local Open Design preview URLs unless the user explicitly

asks for external browsing.

triggers:

• "browser"
• "open website"
• "test this web app"
• "take a screenshot"
• "click a button"
• "fill out a form"
• "scrape page"
• "QA"
• "dogfood"
• "bug hunt"

od:

mode: prototype

surface: web

platform: desktop

scenario: validation

preview:

type: markdown

design_system:

requires: false

upstream: "https://github.com/vercel-labs/agent-browser/blob/main/skills/agent-browser/SKILL.md"

capabilities_required:

• file_write

Agent Browser

Use agent-browser for local Open Design preview validation: inspect rendered

state, click/type when requested, and capture one screenshot when visual evidence

matters. Keep the browser local-first unless the user explicitly asks for

external browsing.

Requirements

Verify the CLI before doing any browser work:

command -v agent-browser

If missing, stop and tell the user to install it:

npm i -g agent-browser
agent-browser install

Do not replace the CLI with ad hoc browser scripts.

Context Hygiene

Never print full upstream guides into chat or tool output. Save them to temp

files and extract only task-relevant lines:

AGENT_BROWSER_CORE="${TMPDIR:-/tmp}/agent-browser-core.$$.md"
agent-browser skills get core > "$AGENT_BROWSER_CORE"
rg -n "cdp|connect|snapshot|screenshot|click|type|wait|get title|get url" "$AGENT_BROWSER_CORE"

Use agent-browser skills get core --full only when needed, and redirect it to

a temp file the same way.

CDP Startup Contract

agent-browser must attach to an existing CDP endpoint. Never run

agent-browser open before agent-browser connect; doing so can make the CLI

auto-launch Chrome and re-enter the crash path.

Use this sequence:

if ! curl -fsS http://127.0.0.1:9223/json/version | rg -q webSocketDebuggerUrl; then
  open -na "Google Chrome" --args \
    --remote-debugging-port=9223 \
    --user-data-dir=/tmp/od-agent-browser-chrome \
    --no-first-run \
    --no-default-browser-check

  for i in {1..20}; do
    if curl -fsS http://127.0.0.1:9223/json/version | rg -q webSocketDebuggerUrl; then
      break
    fi
    sleep 0.5
  done
fi

curl -fsS http://127.0.0.1:9223/json/version | rg webSocketDebuggerUrl
agent-browser connect http://127.0.0.1:9223

If CDP is still unavailable after polling, stop and ask the user to launch

Chrome manually from Terminal:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome \
  --remote-debugging-port=9223 \
  --user-data-dir=/tmp/od-agent-browser-chrome \
  --no-first-run \
  --no-default-browser-check

If Chrome exits before CDP is ready or reports DevToolsActivePort, report:

"Chrome crashed before CDP became available; start Chrome manually with

--remote-debugging-port and retry attach."

Lightpanda is optional. Do not try --engine lightpanda unless

command -v lightpanda succeeds.

Open Design Smoke Path

Use a temp home and stable session:

export HOME=/tmp/agent-browser-home
export AGENT_BROWSER_SESSION=od-local-preview

With the Open Design preview at http://127.0.0.1:17573/, run:

if ! curl -fsS http://127.0.0.1:9223/json/version | rg -q webSocketDebuggerUrl; then
  open -na "Google Chrome" --args \
    --remote-debugging-port=9223 \
    --user-data-dir=/tmp/od-agent-browser-chrome \
    --no-first-run \
    --no-default-browser-check

  for i in {1..20}; do
    if curl -fsS http://127.0.0.1:9223/json/version | rg -q webSocketDebuggerUrl; then
      break
    fi
    sleep 0.5
  done
fi

curl -fsS http://127.0.0.1:9223/json/version | rg webSocketDebuggerUrl
agent-browser connect http://127.0.0.1:9223
agent-browser open http://127.0.0.1:17573/
agent-browser get title
agent-browser get url
agent-browser snapshot
agent-browser screenshot /tmp/od-agent-browser.png

Expected success: title Open Design, current URL under 127.0.0.1:17573,

visible Open Design UI text in the snapshot, and a screenshot at

/tmp/od-agent-browser.png.

Workflow

1. Verify agent-browser is installed.
2. Redirect upstream docs to temp files; quote only relevant lines.
3. Ensure CDP is reachable, starting Chrome with open -na if needed.
4. Connect with agent-browser connect http://127.0.0.1:9223.
5. Open the local preview URL.
6. Snapshot before selecting elements.
7. Use selectors/refs from the latest snapshot; do not guess.
8. Re-snapshot after navigation or UI state changes.
9. Capture one screenshot when visual confirmation matters.
10. Report title, URL, key visible text, screenshot path, and any uncertainty