How it works

From schema upload to frontend traffic in one loop.

GhostAPI is built around the same workflow frontend teams already use: import the backend contract, run the routes, test the UI against real HTTP, then adjust mock behavior as the product changes.

Start a project Open docs

Pipeline

The runtime path

The important detail is that the mock server is generated from normalized endpoints, not static fixtures.

1. Upload the contract: Import OpenAPI 3.x JSON or YAML. GhostAPI validates it, dereferences what it can, and stores the normalized project model instead of leaking raw OpenAPI structures into the runtime.
2. Mount runnable routes: Each normalized endpoint becomes an HTTP route under /mock/{projectId}. Path params, query params, headers, request bodies, response statuses, and media types stay attached to the endpoint.
3. Shape behavior: Use settings and endpoint controls to choose environments, shared headers, latency, saved responses, content types, and auth-oriented test cases.
4. Test from the Playground: Send real requests from the browser, inspect status, headers, body, duration, request metadata, and copy the generated cURL for your own terminal.
5. Debug from activity: Every request can be traced through logs, so frontend failures are connected to the exact method, path, headers, payload, response, and match result.

Contract behavior

What stays reliable

These rules keep schema updates, mock calls, and team access predictable.

Schema uploads add new endpoints and preserve existing duplicates unless override is enabled.
The mock runtime uses project environments and shared headers instead of one-off hardcoded routes.
Request body support covers JSON, text, form-like, binary-safe, and multiple media type choices.
Project members receive role-based access, and invited users can join the platform through the invitation flow.

Request flow

A typical frontend call

Your application calls the mounted mock URL exactly like it would call a real backend.

Frontend request

const response = await fetch(
  "http://localhost:3001/mock/{projectId}/users/42",
  {
    headers: {
      authorization: "Bearer local-dev-token",
      "x-environment": "development"
    }
  }
);

const user = await response.json();