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Agent output

AgentOutputSchema dataclass

An object that captures the JSON schema of the output, as well as validating/parsing JSON produced by the LLM into the output type.

Source code in src/agents/agent_output.py 
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@dataclass(init=False)
class AgentOutputSchema:
    """An object that captures the JSON schema of the output, as well as validating/parsing JSON
    produced by the LLM into the output type.
    """

    output_type: type[Any]
    """The type of the output."""

    _type_adapter: TypeAdapter[Any]
    """A type adapter that wraps the output type, so that we can validate JSON."""

    _is_wrapped: bool
    """Whether the output type is wrapped in a dictionary. This is generally done if the base
    output type cannot be represented as a JSON Schema object.
    """

    _output_schema: dict[str, Any]
    """The JSON schema of the output."""

    strict_json_schema: bool
    """Whether the JSON schema is in strict mode. We **strongly** recommend setting this to True,
    as it increases the likelihood of correct JSON input.
    """

    def __init__(self, output_type: type[Any], strict_json_schema: bool = True):
        """
        Args:
            output_type: The type of the output.
            strict_json_schema: Whether the JSON schema is in strict mode. We **strongly** recommend
                setting this to True, as it increases the likelihood of correct JSON input.
        """
        self.output_type = output_type
        self.strict_json_schema = strict_json_schema

        if output_type is None or output_type is str:
            self._is_wrapped = False
            self._type_adapter = TypeAdapter(output_type)
            self._output_schema = self._type_adapter.json_schema()
            return

        # We should wrap for things that are not plain text, and for things that would definitely
        # not be a JSON Schema object.
        self._is_wrapped = not _is_subclass_of_base_model_or_dict(output_type)

        if self._is_wrapped:
            OutputType = TypedDict(
                "OutputType",
                {
                    _WRAPPER_DICT_KEY: output_type,  # type: ignore
                },
            )
            self._type_adapter = TypeAdapter(OutputType)
            self._output_schema = self._type_adapter.json_schema()
        else:
            self._type_adapter = TypeAdapter(output_type)
            self._output_schema = self._type_adapter.json_schema()

        if self.strict_json_schema:
            self._output_schema = ensure_strict_json_schema(self._output_schema)

    def is_plain_text(self) -> bool:
        """Whether the output type is plain text (versus a JSON object)."""
        return self.output_type is None or self.output_type is str

    def json_schema(self) -> dict[str, Any]:
        """The JSON schema of the output type."""
        if self.is_plain_text():
            raise UserError("Output type is plain text, so no JSON schema is available")
        return self._output_schema

    def validate_json(self, json_str: str, partial: bool = False) -> Any:
        """Validate a JSON string against the output type. Returns the validated object, or raises
        a `ModelBehaviorError` if the JSON is invalid.
        """
        validated = _utils.validate_json(json_str, self._type_adapter, partial)
        if self._is_wrapped:
            if not isinstance(validated, dict):
                _utils.attach_error_to_current_span(
                    SpanError(
                        message="Invalid JSON",
                        data={"details": f"Expected a dict, got {type(validated)}"},
                    )
                )
                raise ModelBehaviorError(
                    f"Expected a dict, got {type(validated)} for JSON: {json_str}"
                )

            if _WRAPPER_DICT_KEY not in validated:
                _utils.attach_error_to_current_span(
                    SpanError(
                        message="Invalid JSON",
                        data={"details": f"Could not find key {_WRAPPER_DICT_KEY} in JSON"},
                    )
                )
                raise ModelBehaviorError(
                    f"Could not find key {_WRAPPER_DICT_KEY} in JSON: {json_str}"
                )
            return validated[_WRAPPER_DICT_KEY]
        return validated

    def output_type_name(self) -> str:
        """The name of the output type."""
        return _type_to_str(self.output_type)

_type_adapter instance-attribute 

_type_adapter: TypeAdapter[Any]

A type adapter that wraps the output type, so that we can validate JSON.

_output_schema instance-attribute 

_output_schema: dict[str, Any]

The JSON schema of the output.

output_type instance-attribute 

output_type: type[Any] = output_type

The type of the output.

strict_json_schema instance-attribute 

strict_json_schema: bool = strict_json_schema

Whether the JSON schema is in strict mode. We strongly recommend setting this to True, as it increases the likelihood of correct JSON input.

_is_wrapped instance-attribute 

_is_wrapped: bool = not _is_subclass_of_base_model_or_dict(
    output_type
)

Whether the output type is wrapped in a dictionary. This is generally done if the base output type cannot be represented as a JSON Schema object.

__init__ 

__init__(
    output_type: type[Any], strict_json_schema: bool = True
)

Parameters:

Name Type Description Default
output_type type[Any]

The type of the output.

 required
strict_json_schema bool

Whether the JSON schema is in strict mode. We strongly recommend setting this to True, as it increases the likelihood of correct JSON input.

 True
Source code in src/agents/agent_output.py 
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def __init__(self, output_type: type[Any], strict_json_schema: bool = True):
    """
    Args:
        output_type: The type of the output.
        strict_json_schema: Whether the JSON schema is in strict mode. We **strongly** recommend
            setting this to True, as it increases the likelihood of correct JSON input.
    """
    self.output_type = output_type
    self.strict_json_schema = strict_json_schema

    if output_type is None or output_type is str:
        self._is_wrapped = False
        self._type_adapter = TypeAdapter(output_type)
        self._output_schema = self._type_adapter.json_schema()
        return

    # We should wrap for things that are not plain text, and for things that would definitely
    # not be a JSON Schema object.
    self._is_wrapped = not _is_subclass_of_base_model_or_dict(output_type)

    if self._is_wrapped:
        OutputType = TypedDict(
            "OutputType",
            {
                _WRAPPER_DICT_KEY: output_type,  # type: ignore
            },
        )
        self._type_adapter = TypeAdapter(OutputType)
        self._output_schema = self._type_adapter.json_schema()
    else:
        self._type_adapter = TypeAdapter(output_type)
        self._output_schema = self._type_adapter.json_schema()

    if self.strict_json_schema:
        self._output_schema = ensure_strict_json_schema(self._output_schema)

is_plain_text 

is_plain_text() -> bool

Whether the output type is plain text (versus a JSON object).

Source code in src/agents/agent_output.py 
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def is_plain_text(self) -> bool:
    """Whether the output type is plain text (versus a JSON object)."""
    return self.output_type is None or self.output_type is str

json_schema 

json_schema() -> dict[str, Any]

The JSON schema of the output type.

Source code in src/agents/agent_output.py 
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def json_schema(self) -> dict[str, Any]:
    """The JSON schema of the output type."""
    if self.is_plain_text():
        raise UserError("Output type is plain text, so no JSON schema is available")
    return self._output_schema

validate_json 

validate_json(json_str: str, partial: bool = False) -> Any

Validate a JSON string against the output type. Returns the validated object, or raises a ModelBehaviorError if the JSON is invalid.

Source code in src/agents/agent_output.py 
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def validate_json(self, json_str: str, partial: bool = False) -> Any:
    """Validate a JSON string against the output type. Returns the validated object, or raises
    a `ModelBehaviorError` if the JSON is invalid.
    """
    validated = _utils.validate_json(json_str, self._type_adapter, partial)
    if self._is_wrapped:
        if not isinstance(validated, dict):
            _utils.attach_error_to_current_span(
                SpanError(
                    message="Invalid JSON",
                    data={"details": f"Expected a dict, got {type(validated)}"},
                )
            )
            raise ModelBehaviorError(
                f"Expected a dict, got {type(validated)} for JSON: {json_str}"
            )

        if _WRAPPER_DICT_KEY not in validated:
            _utils.attach_error_to_current_span(
                SpanError(
                    message="Invalid JSON",
                    data={"details": f"Could not find key {_WRAPPER_DICT_KEY} in JSON"},
                )
            )
            raise ModelBehaviorError(
                f"Could not find key {_WRAPPER_DICT_KEY} in JSON: {json_str}"
            )
        return validated[_WRAPPER_DICT_KEY]
    return validated

output_type_name 

output_type_name() -> str

The name of the output type.

Source code in src/agents/agent_output.py 
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def output_type_name(self) -> str:
    """The name of the output type."""
    return _type_to_str(self.output_type)