E2e Tests Studio

This generates Playwright E2E tests for the Claude playground's frontend, but it's opinionated about what you should actually test. It pushes you hard to validate product behavior (does selecting an LLM provider actually use that provider in requests?) rather than UI states (does the dropdown open?). The prompt includes a test pattern library with examples for configuration changes, data persistence, tool execution, and workflow chaining. It requires the Playwright MCP server and assumes you're working in packages/playground-ui or packages/playground. The mapping table from feature categories to test assertions is genuinely useful if you're the type who writes tests that just check if buttons render.