API Mock Designer Protocol

This skill allows mobile and frontend developers to construct robust UIs without waiting for the backend to be finished. It goes beyond simple static JSON stubs to provide a truly simulated environment that mimics production chaos.

Core assumption: If a frontend only tests against static 200 OK responses, it will break immediately in production when a 503 Service Unavailable or a 4-second latency spike occurs.

0. Context Intake

Before designing, make sure you have the inputs below. Read the previous workflow step's artifact first if it exists. Ask only for what is missing, in a single message, and state any assumption you make instead of blocking.

• The contract (OpenAPI/AsyncAPI file or contract-designer-output.json); without one, list the endpoints you will assume.
• Who consumes the mock (frontend, mobile, partner) and which flows they must exercise.
• Mock tooling already in use (Prism, MSW, WireMock, json-server) or none.