ProviderStrategy Class — langchain Architecture

Source Code

libs/langchain_v1/langchain/agents/structured_output.py lines 261–304

class ProviderStrategy(Generic[SchemaT]):
    """Use the model provider's native structured output method."""

    schema: type[SchemaT] | dict[str, Any]
    """Schema for native mode."""

    schema_spec: _SchemaSpec[SchemaT]
    """Schema spec for native mode."""

    def __init__(
        self,
        schema: type[SchemaT] | dict[str, Any],
        *,
        strict: bool | None = None,
    ) -> None:
        """Initialize `ProviderStrategy` with schema.

        Args:
            schema: Schema to enforce via the provider's native structured output.
            strict: Whether to request strict provider-side schema enforcement.
        """
        self.schema = schema
        self.schema_spec = _SchemaSpec(schema, strict=strict)

    def to_model_kwargs(self) -> dict[str, Any]:
        """Convert to kwargs to bind to a model to force structured output.

        Returns:
            The kwargs to bind to a model.
        """
        # OpenAI:
        # - see https://platform.openai.com/docs/guides/structured-outputs
        json_schema: dict[str, Any] = {
            "name": self.schema_spec.name,
            "schema": self.schema_spec.json_schema,
        }
        if self.schema_spec.strict:
            json_schema["strict"] = True

        response_format: dict[str, Any] = {
            "type": "json_schema",
            "json_schema": json_schema,
        }
        return {"response_format": response_format}