## Zod Guidelines

### Schema Definition
- Define all schemas in `src/types.ts`
- Use `z.object()` for objects, `z.array()` for arrays
- Mark optional fields with `.optional()`
- Create generic schemas for reusable structures

### Type Inference
- Always infer types from schemas: `export type Foo = z.infer<typeof FooSchema>`

### Validation
- Use `.parse()` to validate API responses
- Only validate successful responses (`retcode === RESPONSE_CODES.SUCCESS`)
- Return unvalidated responses for error cases

### Patterns
- Follow existing schema naming: `FooSchema` for schemas, `Foo` for types
- Use `ZZZResponseSchema(dataSchema)` for API responses