Message payload sent from the frontend client to the backend via the transport layer.

Contains the user’s message text, conversation ID, optional frontend context, and file attachments. Sent by SSETransport.send() as the HTTP request body.

Related: AgentTransport defines the send contract, RuntimeInput is the server-side equivalent.

interface TransportMessage {
    type: 'send-message';
    message: string;
    conversationId: string;
    context?: Record<string, unknown>;
    attachments?: Attachment[];
}