Run your tools against your real site.
Playground-style invocations with the real DOM, real selectors, and a response inspector that speaks MCP.
The Playground in the Dev tab generates an args form from every tool's schema and dry-runs it end-to-end. You see the MCP `content[]` response, the duration, and the matched selectors — all without loading the page in another tab.
Args from schema
Every input becomes an interactive control — strings get text inputs, enums get selects, booleans get toggles, emails validate. Nothing to type by hand.
Real selector inspection
The Selectors tab lists every `querySelector()` / `waitForElement()` the tool will call on your page, with copy-to-clipboard — verify a selector in DevTools before shipping.
MCP-shaped responses
Dry runs return the exact `{ content: [{ type: "text", text: "…" }], isError }` envelope your agent SDK expects — including missing-required errors.
{"content": [{"type": "text","text": "Form pre-filled on /app/new. Review and submit."}],"isError": false}