Install and review the Agent Browser skill

Last checked: October 22, 2026, against skillsCatalog.json and the Hermes Browser Automation docs. This lesson does not pin an Agent Browser version. Record the version your install prints.

Agent Browser is the vercel-labs browser CLI skill in the Superbash catalog. The card describes navigate, click, form, screenshot, and extract work, including web and Electron checks. It is not Hermes Browser Use mode, and it is not the browser-use skill.

The catalog command, copied on October 22, 2026, is:

npx skills add vercel-labs/agent-browser --skill agent-browser

The directory card points at the skills.sh page. If that page and the catalog command disagree when you sit down, follow the catalog row you can see that day and write down the difference.

Hermes local browsing is also driven through an agent-browser CLI. That shared name is why this lesson exists. Installing the skill does not select browser.backend. Turning on Hermes Browser Use mode does not install this skill. L12: Browser Use mode is the mode. This lesson is the catalog package.

Finish line

You are done when all of these are true:

you recorded the skill version or the package revision you installed;
you read SKILL.md and noted the tools it asks for before the first browser run;
one reversible task opened a public docs page, returned facts plus the URL, and you re-opened that URL yourself;
no password, cookie, or payment detail appeared in the prompt or the saved notes;
the disposable browser profile is closed, and you know whether you are keeping the skill.

What Agent Browser is, and what it is not

Name	What you are looking at	Install line in the catalog
Agent Browser	This lesson. A CLI skill for browser and Electron tasks	`npx skills add vercel-labs/agent-browser --skill agent-browser`
Hermes Browser Use mode	`browser_exec` inside Hermes. Default when `browser.backend` is unset, and only offered when the session has terminal access	No skills command. Configure it in L12
browser-use	A separate CDP automation skill	`npx skills add browser-use/browser-use --skill browser-use`
Browser Harness	Logged-in browser project. The Hermes docs also describe browser-harness as the engine under Browser Use mode	No catalog command. Do not install it to “enable” the mode
Defuddle	Cleans a page you already have into HTML or Markdown	`npm install -g defuddle`

The first-week checklist is the day-by-day Hermes mode path. The starter stack is the research shelf around it. The 17-item toolkit is the long map, including the “read the source before you install” rule this lesson follows.

Preflight

You need Node and npx on the machine that will install the skill:

node --version
npx --version

If either command is missing, stop. Do not paste a different installer from memory.

Then separate the browser from your real life:

create or choose a disposable browser profile with no personal accounts;
do not point the task at Electron until the web task has passed. The catalog mentions Electron QA. That is a second test, not the first;
tell the agent that submitting a form requires you to approve it, and give it no form to submit.

L04 in this tools track is the stricter pattern for a coding agent: name the sandbox before the model runs. This lesson is narrower. A disposable profile is not a whole-process sandbox. If the page is hostile or the skill’s scripts are unfamiliar, run the install where a bad process cannot see your home directory. L02: Vorssaint is unrelated software; it is only here as the other high-traffic tools lesson if you arrived from the tools hub.

Install from the catalog command

From a directory you can delete, run the catalog command and nothing else:

npx skills add vercel-labs/agent-browser --skill agent-browser

Record:

the working directory;
the version, git revision, or lockfile entry the installer prints;
the path where the skill files landed.

If the installer prompts for extra skills from the same repo, decline them for this review. One package is the experiment.

Inspect before you trust it

Open the installed SKILL.md before the first browse. Treat the folder like a dependency.

Write down:

the commands it tells the agent to run;
any script files beside the markdown;
network, filesystem, and browser permissions it assumes;
whether it expects a logged-in profile.

A Hermes hub install can run a security scan. That scan is not this review. You are checking whether the instructions match a public-page extract. L04: Hermes skills is the lesson for turning your own tested procedure into a skill. L14: SkillEvaluator is the lesson for a repeatable third-party test.

If SKILL.md tells the agent to reuse your default Chrome profile, do not follow that line for this lesson. Point it at the disposable profile instead, or stop.

One bounded review task

Use a public documentation page you can open yourself. The Hermes browser docs are a good fixture because the checklist uses them too:

Open https://hermes-agent.nousresearch.com/docs/user-guide/features/browser
Return a table with the browser provider names you can see on that page.
Include the final URL. Do not sign in, download files, submit forms, or open a second site.
Save a screenshot only if the skill already supports it without extra installs.

Then open the URL in a browser you control and compare the table to the page. Keep the notes, the version, and the screenshot in the disposable directory.

Pass and fail

Check	Pass	Fail
Facts	Provider names match the page you opened	Names are missing, invented, or from a different page
Source	The returned URL opens and is the page you asked for	No URL, or a URL that does not match the table
Credentials	Prompt, notes, and screenshot show no passwords, cookies, or account mail	Any secret appears, even in a screenshot
Scope	No downloads, posts, or extra sites	The agent left the fixture or submitted a form
Evidence	Version and skill path are written down	You cannot tell which files ran

A fluent summary with no URL fails. That is the same bar as L12.

When to use the skill instead of Hermes mode

Situation	Use
Hermes is already installed and Day 2 of the checklist passed	Stay on Browser Use mode. Do not add this skill yet
You want a reusable procedure for the `agent-browser` CLI, including outside Hermes	This skill, after the inspect step
You need CDP automation as its own package	browser-use, as a separate review, not today
You need clean Markdown from a URL you already trust	Defuddle
You need a logged-in browser every day	Not week one. Read Browser Harness in the toolkit before you touch it

Troubleshooting

Problem	What to check
`npx` or the CLI is not found	`node --version` and `npx --version` succeed in the same shell you used to install. Re-copy the catalog command. Do not substitute a different package name.
The run opens an Electron app or the wrong target	The prompt named a website. The catalog also covers Electron QA. Say “web page only” and do not hand it a desktop app path.
The second run still shows the first site’s login	Close the disposable profile. Do not reuse your daily browser. Named Hermes sessions, if you are inside Hermes, separate tabs. They do not delete cookies.
The skill does not show up in Hermes	Install the catalog skill, then send a new message. Hermes tells the open conversation about skills added mid-chat on the next turn. Confirm the files are in the profile skills directory. A successful install still does not switch Browser Use mode on. Check `/browser status` in L12.
Hermes mode works and the skill fails, or the reverse	Keep the one that returned a URL you opened. Record the failure. Do not “fix” it by attaching your real profile.

Cleanup

The catalog does not list an uninstall command. Do not invent one.

delete the trial skill files from the profile you installed into, and write down that path;
close and remove the disposable browser profile;
revoke any token the experiment created;
keep the version note and the pass/fail table if you might reinstall later.

If you are keeping the skill, move the version note next to the task it is allowed to run. A skill with no job gets removed on the next cleanup.

Next step

Next	Why
L12: Browser Use mode	Configure the Hermes driver this skill does not replace
First-week checklist	The day-by-day public-page path
Starter stack	Five skills for a weekly brief, with browser skills left out on purpose
L04: Hermes skills	Save a procedure after it has passed
Skills directory	The card and command this lesson copied
Tools hub	The rest of this module