Structured output

When you need the model to respond with a specific JSON shape instead of free-form text, pass structuredOutput on the InferenceInput you give runLoop. The provider enforces the JSON Schema.

runLoop(agent.getId(), message, {
  model: 'gpt-5.4',
  context: agent.getMemory().getContext(),
  structuredOutput: {
    name: 'weather',
    schema: {
      type: 'object',
      properties: {
        city: { type: 'string' },
        temperature: { type: 'number' },
        condition: { type: 'string' },
      },
      required: ['city', 'temperature', 'condition'],
      additionalProperties: false,
    },
    strict: true,
  },
});

StructuredOutputFormat is { name?: string; schema: Record<string, any>; strict?: boolean }.

The response comes back as a ModelMessageItem with valid JSON in the text field — no new item type. You read it from model.answer ({ answer: ModelMessageItem }) or from inference.completed.

Structured output works alongside tools and streaming. To return to free-form text, omit structuredOutput on the next runLoop.

Provider support

Requesting structured output for a model whose specification has supportsStructuredOutput: false fails validation before the API call.