NonStandardContentBlock Class — langchain Architecture

Source Code

libs/core/langchain_core/messages/content.py lines 790–828

class NonStandardContentBlock(TypedDict):
    """Provider-specific content data.

    This block contains data for which there is not yet a standard type.

    The purpose of this block should be to simply hold a provider-specific payload.
    If a provider's non-standard output includes reasoning and tool calls, it should be
    the adapter's job to parse that payload and emit the corresponding standard
    `ReasoningContentBlock` and `ToolCalls`.

    Has no `extras` field, as provider-specific data should be included in the
    `value` field.

    !!! note "Factory function"

        `create_non_standard_block` may also be used as a factory to create a
        `NonStandardContentBlock`. Benefits include:

        * Automatic ID generation (when not provided)
        * Required arguments strictly validated at creation time
    """

    type: Literal["non_standard"]
    """Type of the content block. Used for discrimination."""

    id: NotRequired[str]
    """Unique identifier for this content block.

    Either:

    - Generated by the provider
    - Generated by LangChain upon creation (`UUID4` prefixed with `'lc_'`))
    """

    value: dict[str, Any]
    """Provider-specific content data."""

    index: NotRequired[int | str]
    """Index of block in aggregate response. Used during streaming."""