Tells Claude to write native Python Playwright scripts and use scripts/with_server.py to manage server lifecycle, with a decision tree for static vs dynamic apps.
What it does
Where webapp-testing runs and what it adds, from its documentation
Writes Playwright scripts against local web apps
Manages one or more dev servers via with_server.py
Captures browser screenshots and console logs
Uses a decision tree: static HTML vs running dynamic app
When to use it
Good fit
Verifying a frontend change in a real browser
Debugging UI behaviour locally
Not for
Testing remote or production sites you do not own
How to install webapp-testing
You need: Python; Playwright
Register the marketplace in Claude Code: /plugin marketplace add anthropics/skills
Install the bundle that contains it (document-skills or example-skills): /plugin install example-skills@anthropic-agent-skills
Or copy the skill folder to ~/.claude/skills/webapp-testing/ (personal) or .claude/skills/webapp-testing/ (project)
Mention the task in a prompt; Claude loads the skill automatically when the SKILL.md description matches
Permissions and security
What it can access
Instructions loaded into Claude's context; any scripts it bundles run through Claude Code's normal tool permissions (shell, file edits)
Security notes from the maintainers
Anthropic repo disclaimer: skills are provided for demonstration and educational purposes; behavior in Claude may differ
Review the source before granting an agent access to credentials or production systems. We document what the maintainers state; we do not audit code.
Limitations
Repo README says implementations are examples and may differ from what Claude.ai provides
How do I install the webapp-testing skill in Claude Code?
Add the marketplace with /plugin marketplace add anthropics/skills and install the bundle containing it, or copy skills/webapp-testing into ~/.claude/skills/. source
When does Claude use the webapp-testing skill?
Claude loads it automatically when the request matches the description field in its SKILL.md frontmatter. source
Is the webapp-testing skill official?
Yes, it is published in Anthropic's anthropics/skills repository. source
