The Backend Bottleneck

Tools like v0 by Vercel or Claude Artifacts allow developers to generate beautiful React components in seconds. But to test how those components handle real data, loading states, and errors, you need an API to fetch from.

Spinning up a full backend server, writing routes, and mocking JSON responses takes longer than generating the UI itself. You need a simple mock API, right now.

Rapidool Mock API Server

Defining a local @GET mock endpoint in Rapidool.

Instant Local Mock Servers

Rapidool turns your scratchpad into a local HTTP server on port 9090. Simply define a route using @GET or @POST, paste your JSON below it, and the endpoint is live instantly.

You can even use the built-in Command Bar to quickly generate UUIDs (/uuid) or connect to Ollama (/gen) to fill your mock API with realistic dummy data.

graph LR A[AI Generates Frontend UI] --> B[Paste JSON into Rapidool]; B --> C[Rapidool hosts on localhost:9090]; A -.->|Fetch Request| C; C -.->|Returns Mock Data| A;

Workflow in 3 Steps

  1. Define the Route: Type @GET /users in Rapidool.
  2. Provide the Data: Paste the mock JSON array directly below the route declaration.
  3. Fetch It: Point your frontend to http://localhost:9090/users. Rapidool serves it instantly with correct CORS headers.
No. The HTTP server is built natively into the macOS application. It runs out of the box with zero dependencies.