@skmtc/gen-tanstack-query-fetch-zod

Produce Tanstack Query hooks (useQuery, useMutation) with fetch as the transport and Zod for runtime validation.

An operation generator. Composes with @skmtc/gen-zod for typed request/response validation. The most-cloned client generator — because the fetch wrapper, error handling, and base URL conventions are almost always team-specific.

Source

skmtc-generators/gen-tanstack-query-fetch-zod/src/

What it generates

Per operation:

export const useGetUser = (args: { id: string }) =>
  useQuery({
    queryKey: ['getUser', args],
    queryFn: () => fetch(`/users/${args.id}`).then(r => r.json()).then(user.parse)
  })

export const useCreateUser = () =>
  useMutation({
    mutationFn: (body: User) =>
      fetch('/users', { method: 'POST', body: JSON.stringify(userBody.parse(body)) })
        .then(r => r.json()).then(user.parse)
  })

The user/userBody Zod schemas come from gen-zod via insertNormalizedModel — both generators share a single registered schema.

Key decisions

isSupported filter. GETs and DELETEs are always supported. POST/PUT/PATCH are supported only if the operation has a request body — operations without a body produce unhelpfully-typed mutations.
GET → useQuery, mutation methods → useMutation. The mapping is hardcoded in the Projection. DELETE goes to useMutation despite typically having no body.
Hardcoded fetch transport. No transport abstraction — the generated code calls fetch directly. This is the canonical customization seam: clone and replace with your own wrapper (axios, custom apiFetch, etc.).
Hardcoded request validation. Request bodies are validated with <schema>.parse(body) before send. Errors throw at call time, not at hook setup.

What to learn from it

isSupported for operation filtering. The body-required check (Boolean(operation.toRequestBody(...))) shows how to gate generation on operation shape, not just method.
Composing with model generators. The hooks reference Zod schemas the form generator also references — the engine produces each schema once, with both generators contributing imports. This is the cross-generator coordination story in practice.
Per-method dispatch in the Projection. GET → query, POST/PUT/PATCH → mutation. The dispatch logic lives in the Projection's toString().

Common customizations when cloned

Swap fetch for a custom wrapper. The most common edit. Your team's apiFetch likely handles auth, retries, and base URL — replace the literal fetch(...) calls.
Customize base URL handling. The stock produces relative paths; most teams want a base-URL prefix (env-driven, or threaded through deps).
Add error handling. The stock throws raw fetch errors. Add retry policies, error boundaries, or transformation to a custom error class.
Add staleTime / gcTime defaults. Per-query overrides via enrichments, or global defaults baked into the generator.