agent-browser

agent-browser is a skill for Claude Code, Codex from a9a4k/tour. It costs 200 tokens per session (686 once invoked), scanned A, a copy of agent-browser, MIT.

A command-line browser automation tool for agents. It uses Chrome or Chromium to navigate pages, inspect their accessibility structure, interact with controls, and capture screenshots or extracted information.

In plain words
What is it for?
Opening websites, filling in forms, clicking buttons, taking screenshots, extracting page data, and testing browser-based applications. It also includes workflows for desktop apps such as Electron, and specialized workflows for services such as Slack.
Why use it?
It removes the need to perform repetitive website actions by hand and gives an agent a structured way to work with pages and test web applications.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/a9a4k/tour/agent-browser
Any agent
npx skills add a9a4k/tour --skill agent-browser
Clone the repo
git clone --depth 1 https://github.com/a9a4k/tour

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for agent-browser

README.md
[![agentmods](https://agentmods.dev/badge/skills/a9a4k/tour/agent-browser.svg)](https://agentmods.dev/skills/a9a4k/tour/agent-browser)
Your own site
<a href="https://agentmods.dev/skills/a9a4k/tour/agent-browser"><img src="https://agentmods.dev/badge/skills/a9a4k/tour/agent-browser.svg" alt="Measured on agentmods" height="20"></a>
Per session 200 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 686 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00200 $0.00686
Opus 5 $0.00100 $0.00343
Sonnet 5 $0.00040 $0.00137
Haiku 4.5 $0.00020 $0.00069

Measured 4d ago against content hash 19ed85bf3f2b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agent-browser scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to agent-browser — 16 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/agent-browser/SKILL.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

agent-browser

Fast browser automation CLI for AI agents. Chrome/Chromium via CDP with accessibility-tree snapshots and compact @eN element refs.

Install: npm i -g agent-browser && agent-browser install

Start here

This file is a discovery stub, not the usage guide. Before running any agent-browser command, load the actual workflow content from the CLI:

agent-browser skills get core             # start here — workflows, common patterns, troubleshooting
agent-browser skills get core --full      # include full command reference and templates

The CLI serves skill content that always matches the installed version, so instructions never go stale. The content in this stub cannot change between releases, which is why it just points at skills get core.

Specialized skills

Load a specialized skill when the task falls outside browser web pages:

agent-browser skills get electron          # Electron desktop apps (VS Code, Slack, Discord, Figma, ...)
agent-browser skills get slack             # Slack workspace automation
agent-browser skills get dogfood           # Exploratory testing / QA / bug hunts
agent-browser skills get vercel-sandbox    # agent-browser inside Vercel Sandbox microVMs
agent-browser skills get agentcore         # AWS Bedrock AgentCore cloud browsers

Run agent-browser skills list to see everything available on the installed version.

Why agent-browser

  • Fast native Rust CLI, not a Node.js wrapper
  • Works with any AI agent (Cursor, Claude Code, Codex, Continue, Windsurf, etc.)
  • Chrome/Chromium via CDP with no Playwright or Puppeteer dependency
  • Accessibility-tree snapshots with element refs for reliable interaction
  • Sessions, authentication vault, state persistence, video recording
  • Specialized skills for Electron apps, Slack, exploratory testing, cloud providers

Observability Dashboard

The dashboard runs independently of browser sessions on port 4848 and can also be opened through a proxied or forwarded URL such as https://dashboard.agent-browser.localhost. Agents should stay on the dashboard origin: session tabs, status, and stream traffic are proxied internally, so session ports do not need to be exposed.

Read the full file on GitHub · 58 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 58 lines · 200 tokens per session scan A 19ed85bf3f2b

Subscribe to this mod's changes

agent-browser is a skill published in the GitHub repository a9a4k/tour (5 stars, last pushed 2mo ago), licensed MIT. It adds 200 tokens to every session and 686 once invoked, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to agent-browser, differing in 16 lines, and is treated as a copy.

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