Agent Browser

What it does

When your agent uses it

• Tasks that involve Browser automation

Example prompts

• “/agent-browser”

Requirements

• Node.js
• Pre-approved tools (allowed-tools): Bash, Read

Workflow steps

4 steps, taken from the step headings in SKILL.md.

1. 1agent-browser の確認
2. 2ユーザーのリクエストを分類
3. 3AI スナップショットワークフロー（推奨）
4. 4結果の確認

What it can do on your machine

Read from SKILL.md and the folder at commit 2b2b748. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Bash
  • Read

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • npm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Agent Browser loads about 1.1k tokens when it runs, and up to ~4.4k if it reads all its reference files. Until then it costs about 69 tokens; SKILL.md has 198 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~69

When it runs · the whole SKILL.md, loaded when a task matches

~1.1k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~4.4k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Bash, Read

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from Chachamaru127/claude-code-harness at commit 2b2b748, republished under its MIT licence (© Chachamaru127). 198 words, ~1,059 tokens.

name

agent-browser

description

Browser automation through the repo agent-browser CLI. Explicit helper for navigation, forms, screenshots, scraping, and web-app checks. Prefer Browser Use or Playwright when available. Do NOT load for: sharing URLs, embedding links, or editing screenshot files.

allowed-tools

Bash, Read

description-en

Browser automation through the repo agent-browser CLI. Explicit helper for navigation, forms, screenshots, scraping, and web-app checks. Prefer Browser Use or…

description-ja

repo の agent-browser CLI でブラウザ操作を行う明示補助スキル。ページ遷移、フォーム、スクショ、スクレイピング、Webアプリ確認向け。利用可能なら Browser Use / Playwright を優先。URL共有、リンク埋め込み、スクショ画像編集には使わない。

user-invocable

false

disable-model-invocation

true

context

fork

argument-hint

[url] [--headless]

# インストール確認
which agent-browser

# インストールを明示依頼され、未インストールの場合のみ
npm install -g agent-browser
agent-browser install

# 1. ページを開く
agent-browser open https://example.com

# 2. スナップショット取得（AI 向け、インタラクティブ要素のみ）
agent-browser snapshot -i -c

# 出力例:
# - link "Home" [ref=e1]
# - button "Login" [ref=e2]
# - input "Email" [ref=e3]
# - input "Password" [ref=e4]
# - button "Submit" [ref=e5]

# 3. 要素参照で操作
agent-browser click @e2           # Login ボタンをクリック
agent-browser fill @e3 "user@example.com"
agent-browser fill @e4 "password123"
agent-browser click @e5           # Submit

# 現在の状態をスナップショットで確認
agent-browser snapshot -i -c

# または URL を確認
agent-browser get url

# スクリーンショットを取得
agent-browser screenshot result.png

# セッションを指定
agent-browser --session admin open https://admin.example.com
agent-browser --session user open https://example.com

# セッション一覧
agent-browser session list

# 特定セッションで操作
agent-browser --session admin snapshot -i -c

© Chachamaru127, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 2 other files (references) in skills/agent-browser of Chachamaru127/claude-code-harness.

• SKILL.md
• references/ai-snapshot-workflow.md
• references/browser-automation.md

Open the folder on GitHubat commit 2b2b748