[Feature Request] Support Schema.prefixItems so that tuple type is supported in response_schema

[Ben-Epstein]

Environment details

• Programming language: python
• OS: macos/linux
• Language runtime version: python 3.10
• Package version: 0.3.0

Steps to reproduce

from google import genai
from google.genai import types
from pydantic import BaseModel

class Answer(BaseModel):
  foo: tuple[int, str]

project_id = ""
client = genai.Client(vertexai=True, project=project_id, location="us-central1")
cfg = types.GenerateContentConfig(
            response_schema=Answer,
            response_mime_type="application/json",
            temperature=0.0,
            seed=42,
        )
res = client.models.generate_content(model="gemini-1.5-flash-002", config=cfg, contents="Pick a value for foo")

response from api

ClientError: 400 INVALID_ARGUMENT. {'error': {'code': 400, 'message': 'Invalid JSON payload received. Unknown name "prefixItems" at \'generation_config.response_schema.properties[0].value\': Cannot find field.', 'status': 'INVALID_ARGUMENT', 'details': [{'@type': 'type.googleapis.com/google.rpc.BadRequest', 'fieldViolations': [{'field': 'generation_config.response_schema.properties[0].value', 'description': 'Invalid JSON payload received. Unknown name "prefixItems" at \'generation_config.response_schema.properties[0].value\': Cannot find field.'}]}]}}

if i pass the class directly I get

ValidationError: 3 validation errors for Schema
properties.foo.minItems
  Input should be a valid string [type=string_type, input_value=2, input_type=int]
    For further information visit https://errors.pydantic.dev/2.10/v/string_type
properties.foo.maxItems
  Input should be a valid string [type=string_type, input_value=2, input_type=int]
    For further information visit https://errors.pydantic.dev/2.10/v/string_type
properties.foo.prefixItems
  Extra inputs are not permitted [type=extra_forbidden, input_value=[{'type': 'INTEGER'}, {'type': 'STRING'}], input_type=list]
    For further information visit https://errors.pydantic.dev/2.10/v/extra_forbidden

see: https://www.learnjsonschema.com/2020-12/applicator/prefixitems/

[happy-qiao]

Hi Ben

prefixItems is not supported by API backend.

properties.foo.minItems and properties.foo.maxItems are SDK bugs. We are working on fixing it.

Thanks

[happy-qiao]

properties.foo.minItems and properties.foo.maxItems type issues are fix now.