40. Advanced Structured Output

Beyond Simple JSON

Basic structured output is getting JSON back from the model. Advanced structured output is building production-grade systems with:

• Deep schemas with nested objects and arrays
• Error handling that's machine-parseable
• Schema evolution without breaking clients
• Internationalization for multi-locale outputs
• Contract testing to ensure compliance

Key Techniques

// Advanced schema with Zod
const ProductCatalogSchema = z.object({
  products: z.array(z.object({
    id: z.string().uuid(),
    name: z.string().min(1),
    price: z.object({
      amount: z.number().positive(),
      currency: z.enum(['USD', 'EUR', 'GBP'])
    }),
    variants: z.array(z.object({
      sku: z.string(),
      attributes: z.record(z.string())  // Flexible key-value
    })).optional(),
    metadata: z.object({
      createdAt: z.string().datetime(),
      tags: z.array(z.string())
    })
  })),
  pagination: z.object({
    page: z.number().int().positive(),
    totalPages: z.number().int().nonnegative(),
    hasMore: z.boolean()
  })
});

Where to go next

• 40.1 Deep schemas: nested objects and arrays
• 40.2 Explain errors as JSON for debuggability
• 40.3 Schema evolution and backwards compatibility
• 40.4 Internationalization schemas: multi-locale outputs
• 40.5 Contract tests for schema compliance