agent-browser

agent-browser is a skill for Claude Code from tmchow/tmc-marketplace. It costs 51 tokens per session (1,505 once invoked), scanned A, original, MIT.

A command-line tool for controlling a web browser, such as opening pages, finding interactive elements, filling forms, and taking screenshots.

In plain words
What is it for?
It helps browse websites, submit forms, navigate between pages, and test web pages using accessibility snapshots and element references.
Why use it?
It lets an agent inspect and operate websites through their visible controls instead of relying only on source code.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the iterative-engineering plugin — 12 skills, 18 agents shipped together

Good fit It helps browse websites, submit forms, navigate between pages, and test web pages using accessibility snapshots and element references.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/tmchow/tmc-marketplace/agent-browser
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.

Any agent
npx skills add tmchow/tmc-marketplace --skill agent-browser
Clone the repo
git clone --depth 1 https://github.com/tmchow/tmc-marketplace

Made for: Claude Code.

Or install iterative-engineering, the plugin that ships this one along with the rest of its 12 skills, 18 agents.

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/tmchow/tmc-marketplace/agent-browser/github.svg)](https://agentmods.dev/skills/tmchow/tmc-marketplace/agent-browser)
Your own site
<a href="https://agentmods.dev/skills/tmchow/tmc-marketplace/agent-browser"><img src="https://agentmods.dev/badge/skills/tmchow/tmc-marketplace/agent-browser/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for agent-browser

Your own site · 80×15
<a href="https://agentmods.dev/skills/tmchow/tmc-marketplace/agent-browser"><img src="https://agentmods.dev/badge/skills/tmchow/tmc-marketplace/agent-browser.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,505 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found 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 5.1 $0.00051 $0.01505
Opus 5 $0.00026 $0.00753
Sonnet 5 $0.00010 $0.00301
Haiku 4.5 $0.00005 $0.00151

Measured 9d ago against content hash 05828793dae5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, 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 9d 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.

plugins/iterative-engineering/skills/agent-browser/SKILL.md · 235 lines

How it starts

The opening of the file, as written. The whole thing — 235 lines — stays where its author put it; the contents beside it link to each section on GitHub.

agent-browser: CLI Browser Automation

Vercel's headless browser CLI designed for AI agents. Uses ref-based selection (@e1, @e2) from accessibility snapshots.

Setup Check

command -v agent-browser >/dev/null 2>&1 && echo "Installed" || echo "NOT INSTALLED"

Install if needed

npm install -g agent-browser
agent-browser install  # Downloads Chromium

Core Workflow

The snapshot + ref pattern is optimal for LLMs:

  1. Navigate to URL
  2. Snapshot to get interactive elements with refs
  3. Interact using refs (@e1, @e2, etc.)
  4. Re-snapshot after navigation or DOM changes
# Step 1: Open URL
agent-browser open https://example.com

# Step 2: Get interactive elements with refs
agent-browser snapshot -i

# Step 3: Interact using refs
agent-browser click @e1
agent-browser fill @e2 "search query"

# Step 4: Re-snapshot after changes
agent-browser snapshot -i

Key Commands

Navigation

agent-browser open <url>       # Navigate to URL
agent-browser back             # Go back
agent-browser forward          # Go forward
agent-browser reload           # Reload page
agent-browser close            # Close browser

Snapshots (Essential for AI)

agent-browser snapshot              # Full accessibility tree
agent-browser snapshot -i           # Interactive elements only (recommended)
agent-browser snapshot -i --json    # JSON output for parsing
agent-browser snapshot -c           # Compact (remove empty elements)
agent-browser snapshot -d 3         # Limit depth
agent-browser snapshot -s @e5       # Scope to element subtree

Interactions

agent-browser click @e1                    # Click element
agent-browser dblclick @e1                 # Double-click
agent-browser fill @e1 "text"              # Clear and fill input
agent-browser type @e1 "text"              # Type without clearing
agent-browser press Enter                  # Press key
agent-browser hover @e1                    # Hover element
agent-browser check @e1                    # Check checkbox
agent-browser uncheck @e1                  # Uncheck checkbox
agent-browser select @e1 "option"          # Select dropdown option
agent-browser scroll down 500              # Scroll (up/down/left/right)
agent-browser scrollintoview @e1           # Scroll element into view

Read the full file on GitHub · 235 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. 9d ago First seen · 235 lines · 51 tokens per session scan A 05828793dae5

Subscribe to this mod's changes

agent-browser is a skill published in the GitHub repository tmchow/tmc-marketplace (22 stars, last pushed 6mo ago), licensed MIT. It adds 51 tokens to every session and 1,505 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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