Card endpoint shape

Card endpoint shape

Every endpoint is a declaration. Four keys, always in this order:

someEndpoint: build.query<Canonical, Request>({
  query: (request) => ({
    url: "/v1/some/path",
    method: "GET",
  }),
  rawResponseSchema: SomeWireSchema, // the wire shape
  transformResponse: transformSome, // wire -> canonical
  responseSchema: SomeSchema, // what callers receive
});

Drop the keys you do not need. An endpoint whose wire shape is already canonical declares responseSchema alone — logout and getUser both do.

Return the wire contract, nothing more. A field the backend never sent does not belong on the answer. If a caller needs one of its own request values afterwards, it already has it.

Never use queryFn

queryFn is the escape hatch for endpoints that are not one HTTP call. None here is, and it costs more than it looks:

• RTK Query skips transformResponse for a queryFn endpoint. getTransformCallbackForEndpoint in buildThunks is guarded by endpointDefinition.query &&. The mapper is silently ignored, so the mapping moves inside the function, by hand.
• The baseQuery result is unknown, so the body needs a cast or a manual safeParse.
• Every one brings its own if (response.error) return { error: response.error }.