GraphQL Data Mocking at Scale with LLMs and @generateMock

Airbnb developed @generateMock, a GraphQL directive that uses LLMs to automatically generate realistic, type-safe mock data for testing and prototyping. The solution combines GraphQL schema validation, product context, and design mockups to produce convincing data without manual effort. Engineers can use @respondWithMock to develop client features before server implementation is complete. The system automatically keeps mocks synchronized with evolving queries through hash-based validation, eliminating the traditional pain points of hand-crafting and maintaining mock data. Over 700 mocks have been generated across Airbnb's platforms since launch.