pydantic_ai.result

ResultDataT module-attribute

ResultDataT = TypeVar(
    "ResultDataT", default=str, covariant=True
)

Covariant type variable for the result data type of a run.

StreamedRunResult dataclass

Bases: Generic[AgentDepsT, ResultDataT]

Result of a streamed run that returns structured data via a tool call.

Source code in pydantic_ai_slim/pydantic_ai/result.py

@dataclass
class StreamedRunResult(Generic[AgentDepsT, ResultDataT]):
    """Result of a streamed run that returns structured data via a tool call."""

    _all_messages: list[_messages.ModelMessage]
    _new_message_index: int

    _usage_limits: UsageLimits | None
    _stream_response: models.StreamedResponse
    _result_schema: _result.ResultSchema[ResultDataT] | None
    _run_ctx: RunContext[AgentDepsT]
    _result_validators: list[_result.ResultValidator[AgentDepsT, ResultDataT]]
    _result_tool_name: str | None
    _on_complete: Callable[[], Awaitable[None]]

    _initial_run_ctx_usage: Usage = field(init=False)
    is_complete: bool = field(default=False, init=False)
    """Whether the stream has all been received.

    This is set to `True` when one of
    [`stream`][pydantic_ai.result.StreamedRunResult.stream],
    [`stream_text`][pydantic_ai.result.StreamedRunResult.stream_text],
    [`stream_structured`][pydantic_ai.result.StreamedRunResult.stream_structured] or
    [`get_data`][pydantic_ai.result.StreamedRunResult.get_data] completes.
    """

    def __post_init__(self):
        self._initial_run_ctx_usage = copy(self._run_ctx.usage)

    def all_messages(self, *, result_tool_return_content: str | None = None) -> list[_messages.ModelMessage]:
        """Return the history of _messages.

        Args:
            result_tool_return_content: The return content of the tool call to set in the last message.
                This provides a convenient way to modify the content of the result tool call if you want to continue
                the conversation and want to set the response to the result tool call. If `None`, the last message will
                not be modified.

        Returns:
            List of messages.
        """
        # this is a method to be consistent with the other methods
        if result_tool_return_content is not None:
            raise NotImplementedError('Setting result tool return content is not supported for this result type.')
        return self._all_messages

    def all_messages_json(self, *, result_tool_return_content: str | None = None) -> bytes:
        """Return all messages from [`all_messages`][pydantic_ai.result.StreamedRunResult.all_messages] as JSON bytes.

        Args:
            result_tool_return_content: The return content of the tool call to set in the last message.
                This provides a convenient way to modify the content of the result tool call if you want to continue
                the conversation and want to set the response to the result tool call. If `None`, the last message will
                not be modified.

        Returns:
            JSON bytes representing the messages.
        """
        return _messages.ModelMessagesTypeAdapter.dump_json(
            self.all_messages(result_tool_return_content=result_tool_return_content)
        )

    def new_messages(self, *, result_tool_return_content: str | None = None) -> list[_messages.ModelMessage]:
        """Return new messages associated with this run.

        Messages from older runs are excluded.

        Args:
            result_tool_return_content: The return content of the tool call to set in the last message.
                This provides a convenient way to modify the content of the result tool call if you want to continue
                the conversation and want to set the response to the result tool call. If `None`, the last message will
                not be modified.

        Returns:
            List of new messages.
        """
        return self.all_messages(result_tool_return_content=result_tool_return_content)[self._new_message_index :]

    def new_messages_json(self, *, result_tool_return_content: str | None = None) -> bytes:
        """Return new messages from [`new_messages`][pydantic_ai.result.StreamedRunResult.new_messages] as JSON bytes.

        Args:
            result_tool_return_content: The return content of the tool call to set in the last message.
                This provides a convenient way to modify the content of the result tool call if you want to continue
                the conversation and want to set the response to the result tool call. If `None`, the last message will
                not be modified.

        Returns:
            JSON bytes representing the new messages.
        """
        return _messages.ModelMessagesTypeAdapter.dump_json(
            self.new_messages(result_tool_return_content=result_tool_return_content)
        )

    async def stream(self, *, debounce_by: float | None = 0.1) -> AsyncIterator[ResultDataT]:
        """Stream the response as an async iterable.

        The pydantic validator for structured data will be called in
        [partial mode](https://docs.pydantic.dev/dev/concepts/experimental/#partial-validation)
        on each iteration.

        Args:
            debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
                Debouncing is particularly important for long structured responses to reduce the overhead of
                performing validation as each token is received.

        Returns:
            An async iterable of the response data.
        """
        async for structured_message, is_last in self.stream_structured(debounce_by=debounce_by):
            result = await self.validate_structured_result(structured_message, allow_partial=not is_last)
            yield result

    async def stream_text(self, *, delta: bool = False, debounce_by: float | None = 0.1) -> AsyncIterator[str]:
        """Stream the text result as an async iterable.

        !!! note
            Result validators will NOT be called on the text result if `delta=True`.

        Args:
            delta: if `True`, yield each chunk of text as it is received, if `False` (default), yield the full text
                up to the current point.
            debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
                Debouncing is particularly important for long structured responses to reduce the overhead of
                performing validation as each token is received.
        """
        if self._result_schema and not self._result_schema.allow_text_result:
            raise exceptions.UserError('stream_text() can only be used with text responses')

        if delta:
            async for text in self._stream_response_text(delta=delta, debounce_by=debounce_by):
                yield text
        else:
            async for text in self._stream_response_text(delta=delta, debounce_by=debounce_by):
                combined_validated_text = await self._validate_text_result(text)
                yield combined_validated_text
        await self._marked_completed(self._stream_response.get())

    async def stream_structured(
        self, *, debounce_by: float | None = 0.1
    ) -> AsyncIterator[tuple[_messages.ModelResponse, bool]]:
        """Stream the response as an async iterable of Structured LLM Messages.

        Args:
            debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
                Debouncing is particularly important for long structured responses to reduce the overhead of
                performing validation as each token is received.

        Returns:
            An async iterable of the structured response message and whether that is the last message.
        """
        # if the message currently has any parts with content, yield before streaming
        msg = self._stream_response.get()
        for part in msg.parts:
            if part.has_content():
                yield msg, False
                break

        async for msg in self._stream_response_structured(debounce_by=debounce_by):
            yield msg, False

        msg = self._stream_response.get()
        yield msg, True

        await self._marked_completed(msg)

    async def get_data(self) -> ResultDataT:
        """Stream the whole response, validate and return it."""
        usage_checking_stream = _get_usage_checking_stream_response(
            self._stream_response, self._usage_limits, self.usage
        )

        async for _ in usage_checking_stream:
            pass
        message = self._stream_response.get()
        await self._marked_completed(message)
        return await self.validate_structured_result(message)

    def usage(self) -> Usage:
        """Return the usage of the whole run.

        !!! note
            This won't return the full usage until the stream is finished.
        """
        return self._initial_run_ctx_usage + self._stream_response.usage()

    def timestamp(self) -> datetime:
        """Get the timestamp of the response."""
        return self._stream_response.timestamp

    async def validate_structured_result(
        self, message: _messages.ModelResponse, *, allow_partial: bool = False
    ) -> ResultDataT:
        """Validate a structured result message."""
        if self._result_schema is not None and self._result_tool_name is not None:
            match = self._result_schema.find_named_tool(message.parts, self._result_tool_name)
            if match is None:
                raise exceptions.UnexpectedModelBehavior(
                    f'Invalid response, unable to find tool: {self._result_schema.tool_names()}'
                )

            call, result_tool = match
            result_data = result_tool.validate(call, allow_partial=allow_partial, wrap_validation_errors=False)

            for validator in self._result_validators:
                result_data = await validator.validate(result_data, call, self._run_ctx)
            return result_data
        else:
            text = '\n\n'.join(x.content for x in message.parts if isinstance(x, _messages.TextPart))
            for validator in self._result_validators:
                text = await validator.validate(
                    text,
                    None,
                    self._run_ctx,
                )
            # Since there is no result tool, we can assume that str is compatible with ResultDataT
            return cast(ResultDataT, text)

    async def _validate_text_result(self, text: str) -> str:
        for validator in self._result_validators:
            text = await validator.validate(
                text,
                None,
                self._run_ctx,
            )
        return text

    async def _marked_completed(self, message: _messages.ModelResponse) -> None:
        self.is_complete = True
        self._all_messages.append(message)
        await self._on_complete()

    async def _stream_response_structured(
        self, *, debounce_by: float | None = 0.1
    ) -> AsyncIterator[_messages.ModelResponse]:
        async with _utils.group_by_temporal(self._stream_response, debounce_by) as group_iter:
            async for _items in group_iter:
                yield self._stream_response.get()

    async def _stream_response_text(
        self, *, delta: bool = False, debounce_by: float | None = 0.1
    ) -> AsyncIterator[str]:
        """Stream the response as an async iterable of text."""

        # Define a "merged" version of the iterator that will yield items that have already been retrieved
        # and items that we receive while streaming. We define a dedicated async iterator for this so we can
        # pass the combined stream to the group_by_temporal function within `_stream_text_deltas` below.
        async def _stream_text_deltas_ungrouped() -> AsyncIterator[tuple[str, int]]:
            # yields tuples of (text_content, part_index)
            # we don't currently make use of the part_index, but in principle this may be useful
            # so we retain it here for now to make possible future refactors simpler
            msg = self._stream_response.get()
            for i, part in enumerate(msg.parts):
                if isinstance(part, _messages.TextPart) and part.content:
                    yield part.content, i

            async for event in self._stream_response:
                if (
                    isinstance(event, _messages.PartStartEvent)
                    and isinstance(event.part, _messages.TextPart)
                    and event.part.content
                ):
                    yield event.part.content, event.index
                elif (
                    isinstance(event, _messages.PartDeltaEvent)
                    and isinstance(event.delta, _messages.TextPartDelta)
                    and event.delta.content_delta
                ):
                    yield event.delta.content_delta, event.index

        async def _stream_text_deltas() -> AsyncIterator[str]:
            async with _utils.group_by_temporal(_stream_text_deltas_ungrouped(), debounce_by) as group_iter:
                async for items in group_iter:
                    # Note: we are currently just dropping the part index on the group here
                    yield ''.join([content for content, _ in items])

        if delta:
            async for text in _stream_text_deltas():
                yield text
        else:
            # a quick benchmark shows it's faster to build up a string with concat when we're
            # yielding at each step
            deltas: list[str] = []
            async for text in _stream_text_deltas():
                deltas.append(text)
                yield ''.join(deltas)

is_complete class-attribute instance-attribute

is_complete: bool = field(default=False, init=False)

Whether the stream has all been received.

This is set to True when one of stream, stream_text, stream_structured or get_data completes.

all_messages

all_messages(
    *, result_tool_return_content: str | None = None
) -> list[ModelMessage]

Return the history of _messages.

Parameters:

Name	Type	Description	Default
result_tool_return_content	str | None	The return content of the tool call to set in the last message. This provides a convenient way to modify the content of the result tool call if you want to continue the conversation and want to set the response to the result tool call. If None, the last message will not be modified.	None

Returns:

Type	Description
list[ModelMessage]	List of messages.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def all_messages(self, *, result_tool_return_content: str | None = None) -> list[_messages.ModelMessage]:
    """Return the history of _messages.

    Args:
        result_tool_return_content: The return content of the tool call to set in the last message.
            This provides a convenient way to modify the content of the result tool call if you want to continue
            the conversation and want to set the response to the result tool call. If `None`, the last message will
            not be modified.

    Returns:
        List of messages.
    """
    # this is a method to be consistent with the other methods
    if result_tool_return_content is not None:
        raise NotImplementedError('Setting result tool return content is not supported for this result type.')
    return self._all_messages

all_messages_json

all_messages_json(
    *, result_tool_return_content: str | None = None
) -> bytes

Return all messages from all_messages as JSON bytes.

Parameters:

Name	Type	Description	Default
result_tool_return_content	str | None	The return content of the tool call to set in the last message. This provides a convenient way to modify the content of the result tool call if you want to continue the conversation and want to set the response to the result tool call. If None, the last message will not be modified.	None

Returns:

Type	Description
bytes	JSON bytes representing the messages.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def all_messages_json(self, *, result_tool_return_content: str | None = None) -> bytes:
    """Return all messages from [`all_messages`][pydantic_ai.result.StreamedRunResult.all_messages] as JSON bytes.

    Args:
        result_tool_return_content: The return content of the tool call to set in the last message.
            This provides a convenient way to modify the content of the result tool call if you want to continue
            the conversation and want to set the response to the result tool call. If `None`, the last message will
            not be modified.

    Returns:
        JSON bytes representing the messages.
    """
    return _messages.ModelMessagesTypeAdapter.dump_json(
        self.all_messages(result_tool_return_content=result_tool_return_content)
    )

new_messages

new_messages(
    *, result_tool_return_content: str | None = None
) -> list[ModelMessage]

Return new messages associated with this run.

Messages from older runs are excluded.

Parameters:

Name	Type	Description	Default
result_tool_return_content	str | None	The return content of the tool call to set in the last message. This provides a convenient way to modify the content of the result tool call if you want to continue the conversation and want to set the response to the result tool call. If None, the last message will not be modified.	None

Returns:

Type	Description
list[ModelMessage]	List of new messages.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def new_messages(self, *, result_tool_return_content: str | None = None) -> list[_messages.ModelMessage]:
    """Return new messages associated with this run.

    Messages from older runs are excluded.

    Args:
        result_tool_return_content: The return content of the tool call to set in the last message.
            This provides a convenient way to modify the content of the result tool call if you want to continue
            the conversation and want to set the response to the result tool call. If `None`, the last message will
            not be modified.

    Returns:
        List of new messages.
    """
    return self.all_messages(result_tool_return_content=result_tool_return_content)[self._new_message_index :]

new_messages_json

new_messages_json(
    *, result_tool_return_content: str | None = None
) -> bytes

Return new messages from new_messages as JSON bytes.

Parameters:

Name	Type	Description	Default
result_tool_return_content	str | None	The return content of the tool call to set in the last message. This provides a convenient way to modify the content of the result tool call if you want to continue the conversation and want to set the response to the result tool call. If None, the last message will not be modified.	None

Returns:

Type	Description
bytes	JSON bytes representing the new messages.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def new_messages_json(self, *, result_tool_return_content: str | None = None) -> bytes:
    """Return new messages from [`new_messages`][pydantic_ai.result.StreamedRunResult.new_messages] as JSON bytes.

    Args:
        result_tool_return_content: The return content of the tool call to set in the last message.
            This provides a convenient way to modify the content of the result tool call if you want to continue
            the conversation and want to set the response to the result tool call. If `None`, the last message will
            not be modified.

    Returns:
        JSON bytes representing the new messages.
    """
    return _messages.ModelMessagesTypeAdapter.dump_json(
        self.new_messages(result_tool_return_content=result_tool_return_content)
    )

stream async

stream(
    *, debounce_by: float | None = 0.1
) -> AsyncIterator[ResultDataT]

Stream the response as an async iterable.

The pydantic validator for structured data will be called in partial mode on each iteration.

Parameters:

Name	Type	Description	Default
debounce_by	float | None	by how much (if at all) to debounce/group the response chunks by. None means no debouncing. Debouncing is particularly important for long structured responses to reduce the overhead of performing validation as each token is received.	0.1

Returns:

Type	Description
AsyncIterator[ResultDataT]	An async iterable of the response data.

Source code in pydantic_ai_slim/pydantic_ai/result.py

async def stream(self, *, debounce_by: float | None = 0.1) -> AsyncIterator[ResultDataT]:
    """Stream the response as an async iterable.

    The pydantic validator for structured data will be called in
    [partial mode](https://docs.pydantic.dev/dev/concepts/experimental/#partial-validation)
    on each iteration.

    Args:
        debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
            Debouncing is particularly important for long structured responses to reduce the overhead of
            performing validation as each token is received.

    Returns:
        An async iterable of the response data.
    """
    async for structured_message, is_last in self.stream_structured(debounce_by=debounce_by):
        result = await self.validate_structured_result(structured_message, allow_partial=not is_last)
        yield result

stream_text async

stream_text(
    *, delta: bool = False, debounce_by: float | None = 0.1
) -> AsyncIterator[str]

Stream the text result as an async iterable.

Note

Result validators will NOT be called on the text result if delta=True.

Parameters:

Name	Type	Description	Default
delta	bool	if True, yield each chunk of text as it is received, if False (default), yield the full text up to the current point.	False
debounce_by	float | None	by how much (if at all) to debounce/group the response chunks by. None means no debouncing. Debouncing is particularly important for long structured responses to reduce the overhead of performing validation as each token is received.	0.1

Source code in pydantic_ai_slim/pydantic_ai/result.py

async def stream_text(self, *, delta: bool = False, debounce_by: float | None = 0.1) -> AsyncIterator[str]:
    """Stream the text result as an async iterable.

    !!! note
        Result validators will NOT be called on the text result if `delta=True`.

    Args:
        delta: if `True`, yield each chunk of text as it is received, if `False` (default), yield the full text
            up to the current point.
        debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
            Debouncing is particularly important for long structured responses to reduce the overhead of
            performing validation as each token is received.
    """
    if self._result_schema and not self._result_schema.allow_text_result:
        raise exceptions.UserError('stream_text() can only be used with text responses')

    if delta:
        async for text in self._stream_response_text(delta=delta, debounce_by=debounce_by):
            yield text
    else:
        async for text in self._stream_response_text(delta=delta, debounce_by=debounce_by):
            combined_validated_text = await self._validate_text_result(text)
            yield combined_validated_text
    await self._marked_completed(self._stream_response.get())

stream_structured async

stream_structured(
    *, debounce_by: float | None = 0.1
) -> AsyncIterator[tuple[ModelResponse, bool]]

Stream the response as an async iterable of Structured LLM Messages.

Parameters:

Name	Type	Description	Default
debounce_by	float | None	by how much (if at all) to debounce/group the response chunks by. None means no debouncing. Debouncing is particularly important for long structured responses to reduce the overhead of performing validation as each token is received.	0.1

Returns:

Type	Description
AsyncIterator[tuple[ModelResponse, bool]]	An async iterable of the structured response message and whether that is the last message.

Source code in pydantic_ai_slim/pydantic_ai/result.py

async def stream_structured(
    self, *, debounce_by: float | None = 0.1
) -> AsyncIterator[tuple[_messages.ModelResponse, bool]]:
    """Stream the response as an async iterable of Structured LLM Messages.

    Args:
        debounce_by: by how much (if at all) to debounce/group the response chunks by. `None` means no debouncing.
            Debouncing is particularly important for long structured responses to reduce the overhead of
            performing validation as each token is received.

    Returns:
        An async iterable of the structured response message and whether that is the last message.
    """
    # if the message currently has any parts with content, yield before streaming
    msg = self._stream_response.get()
    for part in msg.parts:
        if part.has_content():
            yield msg, False
            break

    async for msg in self._stream_response_structured(debounce_by=debounce_by):
        yield msg, False

    msg = self._stream_response.get()
    yield msg, True

    await self._marked_completed(msg)

get_data async

get_data() -> ResultDataT

Stream the whole response, validate and return it.

Source code in pydantic_ai_slim/pydantic_ai/result.py

async def get_data(self) -> ResultDataT:
    """Stream the whole response, validate and return it."""
    usage_checking_stream = _get_usage_checking_stream_response(
        self._stream_response, self._usage_limits, self.usage
    )

    async for _ in usage_checking_stream:
        pass
    message = self._stream_response.get()
    await self._marked_completed(message)
    return await self.validate_structured_result(message)

usage

usage() -> Usage

Return the usage of the whole run.

Note

This won't return the full usage until the stream is finished.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def usage(self) -> Usage:
    """Return the usage of the whole run.

    !!! note
        This won't return the full usage until the stream is finished.
    """
    return self._initial_run_ctx_usage + self._stream_response.usage()

timestamp

timestamp() -> datetime

Get the timestamp of the response.

Source code in pydantic_ai_slim/pydantic_ai/result.py

def timestamp(self) -> datetime:
    """Get the timestamp of the response."""
    return self._stream_response.timestamp

validate_structured_result async

validate_structured_result(
    message: ModelResponse, *, allow_partial: bool = False
) -> ResultDataT

Validate a structured result message.

Source code in pydantic_ai_slim/pydantic_ai/result.py

async def validate_structured_result(
    self, message: _messages.ModelResponse, *, allow_partial: bool = False
) -> ResultDataT:
    """Validate a structured result message."""
    if self._result_schema is not None and self._result_tool_name is not None:
        match = self._result_schema.find_named_tool(message.parts, self._result_tool_name)
        if match is None:
            raise exceptions.UnexpectedModelBehavior(
                f'Invalid response, unable to find tool: {self._result_schema.tool_names()}'
            )

        call, result_tool = match
        result_data = result_tool.validate(call, allow_partial=allow_partial, wrap_validation_errors=False)

        for validator in self._result_validators:
            result_data = await validator.validate(result_data, call, self._run_ctx)
        return result_data
    else:
        text = '\n\n'.join(x.content for x in message.parts if isinstance(x, _messages.TextPart))
        for validator in self._result_validators:
            text = await validator.validate(
                text,
                None,
                self._run_ctx,
            )
        # Since there is no result tool, we can assume that str is compatible with ResultDataT
        return cast(ResultDataT, text)