Signal · Methods

signal.schema

signal.schema(zodSchema) sets the Zod schema for structured output. If the provider supports JSON Schema output, Signal sends the schema as a json_schema response_format; in every case the response is parsed and validated locally against the Zod schema, and the returned response is typed. The model’s reply is scripted; no model is called.

Schema

z.object({ show: z.string(), seats: z.number() })

Request

{
  model: 'written-here',
  messages: [
    {
      role: 'user',
      content: 'Two for The Tempest on Saturday, please. Grace',
    },
  ],
  response_format: {
    type: 'json_schema',
    json_schema: {
      name: 'output',
      strict: false,
      schema: {
        $schema: 'http://json-schema.org/draft-07/schema#',
        type: 'object',
        properties: { show: { type: 'string' }, seats: { type: 'number' } },
        required: ['show', 'seats'],
        additionalProperties: false,
      },
    },
  },
  stream: true,
  stream_options: { include_usage: true },
}

Scripted model reply

{"show":"The Tempest","seats":2}

Output

{ show: 'The Tempest', seats: 2 }

Output matches the expected value

Runs in this page on the installed package. The input and the expected output are defined by the example.