openapi-ts-client

Install @hey-api/openapi-ts as a dev dependency, create an openapi-ts.config.ts with your spec URL or file path as input and an output directory, then run the openapi-ts command via a package.json script. It emits typed models and one typed function per operation.

Add the framework-specific plugin string such as @tanstack/react-query to the plugins array in openapi-ts.config.ts. The generator emits Options, QueryKey, InfiniteOptions, and Mutation helpers per operation that you spread into useQuery or useMutation.

Yes, FastAPI's own documentation recommends @hey-api/openapi-ts for TypeScript clients. FastAPI 0.99 and later emits OpenAPI 3.1, which is exactly what hey-api targets; point the input at the running app's /openapi.json endpoint.

FastAPI builds verbose default operationIds, which become method names. Fix it on the backend by setting generate_unique_id_function on the FastAPI app to produce tag-name style operationIds, so every regeneration yields clean names.

Both are valid. Committing makes API changes reviewable in diffs and removes the codegen build step, but requires a CI drift check (regenerate then git diff --exit-code) to prevent staleness. Gitignoring avoids churn but every environment must run codegen first.

Avoid it when you only need TanStack Query usage patterns like caching and invalidation, when you are authoring the backend or OpenAPI spec itself, or when you are locked to an OpenAPI 3.0-only workflow requiring a 3.0-specialized tool.