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.
npx skills add kumaran-is/claude-code-onboarding --skill browser-testinggit clone --depth 1 https://github.com/kumaran-is/claude-code-onboardingWrote 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.
[](https://agentmods.dev/skills/kumaran-is/claude-code-onboarding/browser-testing)<a href="https://agentmods.dev/skills/kumaran-is/claude-code-onboarding/browser-testing"><img src="https://agentmods.dev/badge/skills/kumaran-is/claude-code-onboarding/browser-testing/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.
<a href="https://agentmods.dev/skills/kumaran-is/claude-code-onboarding/browser-testing"><img src="https://agentmods.dev/badge/skills/kumaran-is/claude-code-onboarding/browser-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00074 | $0.02139 |
| Opus 5 | $0.00037 | $0.01069 |
| Sonnet 5 | $0.00015 | $0.00428 |
| Haiku 4.5 | $0.00007 | $0.00214 |
Grade A, and why
browser-testing 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 188 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Iron Law: Never claim a UI flow works without running it in a real browser. Use playwright-cli (Bash) for inspection and scripted steps; use Browser-Use MCP for autonomous goal-driven flows.
Browser Automation & Testing Skill
This skill combines two tools for complete browser automation:
- playwright-cli — stateful Bash CLI for deterministic scripted tests (navigation, snapshots, screenshots, network/console inspection, tracing)
- Browser-Use MCP — autonomous agent for goal-driven interaction (describe a goal, not steps)
Install & Setup
# Install (package name is @playwright/mcp; binary is playwright-cli)
npm install -g @playwright/mcp@latest
# Initialize workspace (downloads browsers)
playwright-cli install
# Verify
playwright-cli --version
Session Model
playwright-cli is stateful — each named session persists browser state across commands:
# Use -s flag to name a session (persists across calls)
playwright-cli -s=login-test goto http://localhost:4200/login
playwright-cli -s=login-test snapshot
playwright-cli -s=login-test fill [email-ref] "[email protected]"
playwright-cli -s=login-test click [submit-ref]
# Without -s: uses a default unnamed session
playwright-cli goto http://localhost:4200
When to Use Which Tool
| Task | playwright-cli (Bash) | Browser-Use MCP |
|---|---|---|
| Scripted test steps | Preferred | Works |
| Network request list | playwright-cli network |
Not available |
| Console messages | playwright-cli console |
Not available |
| Execute JavaScript | playwright-cli eval <func> |
Not available |
| Performance tracing | playwright-cli tracing-start/stop |
Not available |
| Accessibility tree | playwright-cli snapshot |
Not available |
| Autonomous goal completion | Needs scripting | Preferred |
| Real Chrome with existing login | Limited | --browser real |
Rule: Default to playwright-cli. Use Browser-Use only when describing a goal is better than scripting steps.
What ships with it
8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- reference/agentic-debug-loop.md 9.0 KB
- reference/api-performance.md 4.6 KB
- reference/browser-testing-workflows.md 16 KB
- reference/browser-use-tools.md 10 KB
- reference/chrome-devtools-tools.md 8.2 KB
- reference/playwright-cli-tools.md 8.0 KB
- reference/playwright-test-suite.md 8.3 KB
- scripts/with_server.py 5.4 KB runs code
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.
- 6d ago First seen · 188 lines · 74 tokens per session scan A 1e1898c2af16
browser-testing is a skill published in the GitHub repository kumaran-is/claude-code-onboarding (35 stars, last pushed 2mo ago), licensed MIT. It adds 74 tokens to every session and 2,139 once invoked, about $0.0004 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 2026-09-03.
Other skills, from other repositories
browse
Drive a real browser through Aside: open a page, read it, click through a flow, take screenshots, check console errors. (gstack).
playwright-cli
A command-line tool for controlling Chromium, Firefox, and WebKit browsers, including navigation, page interaction, screenshots, PDFs, and recorded actions.
webapp-testing
Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.
create-verification-skill
Create a repo-local verification skill and exhaustive feature map for driving a real app through its UI, CLI, or API. Use for "create a verification skill", "make a verify skill for this repo", or "document how agents can verify this app".
browser-qa
A browser-based quality check for deployed web pages and user flows. It uses browser automation to test rendering, navigation, forms, interactions, responsive behaviour, and accessibility-related issues.
test-electron-app
Drive the real running PostHog Electron app (live tRPC, workspace-server, real data) over CDP with agent-browser. Connect to the running app on port 9222, test desktop changes against a local Django stack, snapshot the accessibility tree, inspect network requests, and screenshot only when explicitly asked. Use when…