ChatMessage

A message in a chat.

Usage

import marimo as mo

# Create a user message
message = mo.ai.ChatMessage(
    role="user",
    content="Hello, how are you?",
    id="msg-1"
)

# Create an assistant message with parts
message = mo.ai.ChatMessage(
    role="assistant",
    content="I'm doing well, thank you!",
    id="msg-2",
    parts=[
        {"type": "text", "text": "I'm doing well, thank you!"}
    ]
)

# Create a message with attachments
attachment = mo.ai.ChatAttachment(
    url="https://example.com/image.png",
    name="example.png"
)

message = mo.ai.ChatMessage(
    role="user",
    content="Look at this image",
    id="msg-3",
    attachments=[attachment]
)

Signature

mo.ai.ChatMessage(
    role: Literal["user", "assistant", "system"],
    content: Any,
    id: str = "",
    parts: list[ChatPart] = [],
    attachments: Optional[list[ChatAttachment]] = None,
    metadata: Any | None = None
)

Parameters

role · Literal['user', 'assistant', 'system'] · required

The role of the message.

content · Any · required

The content of the message. This can be a rich Python object.

id · str · default: "''"

The id of the message.

parts · list[ChatPart] · default: "[]"

Parts from AI SDK Stream Protocol (must be serializable to JSON).

attachments · Optional[list[ChatAttachment]] · default: "None"

Optional attachments to the message.

metadata · Any | None · default: "None"

Optional metadata.

Part Types

TextPart

Represents a text content part.

Attributes:

• type (Literal[“text”]): Part type
• text (str): The text content

ReasoningPart

Represents a reasoning content part.

Attributes:

• type (Literal[“reasoning”]): Part type
• text (str): The reasoning text
• details (Optional[list[ReasoningDetails]]): Optional reasoning details

ToolInvocationPart

Represents a tool invocation part from the AI SDK.

Attributes:

• type (str): Starts with “tool-”
• tool_call_id (str): The tool call identifier
• state (Union[str, Literal[“output-available”]]): The state of the invocation
• input (dict[str, Any]): The input to the tool
• output (Optional[Any]): The output from the tool

Properties:

• tool_name: Returns the tool name (extracted from type)

FilePart

Represents a FileUIPart from the AI SDK.

Attributes:

• type (Literal[“file”]): Part type
• media_type (str): The media type
• url (str): The file URL
• filename (Optional[str]): Optional filename