Beta Managed Agents Agent Thread Message Sent Event

• BetaManagedAgentsAgentThreadMessageSentEvent object

  Observability event emitted to the sender's output stream when an agent-to-agent message is sent.

  • type: "agent.thread_message_sent"

  • id: string

    Unique identifier for this event.

  • content: array of BetaManagedAgentsTextBlock or BetaManagedAgentsImageBlock or BetaManagedAgentsDocumentBlock or BetaManagedAgentsRedactedBlock

    Message content blocks.

    • BetaManagedAgentsTextBlock object

      Regular text content.

      • type: "text"

      • text: string

        The text content.

        minLength: 1

    • BetaManagedAgentsImageBlock object

      Image content specified directly as base64 data or as a reference via a URL.

      • type: "image"

      • source: BetaManagedAgentsBase64ImageSource or BetaManagedAgentsURLImageSource or BetaManagedAgentsFileImageSource

        Union type for image source variants.

        • BetaManagedAgentsBase64ImageSource object

          Base64-encoded image data.

          • type: "base64"

          • data: string

            Base64-encoded image data.

            minLength: 1

          • media_type: string

            MIME type of the image (e.g., "image/png", "image/jpeg", "image/gif", "image/webp").

            minLength: 1

        • BetaManagedAgentsURLImageSource object

          Image referenced by URL.

          • type: "url"

          • url: string

            URL of the image to fetch.

            minLength: 1

        • BetaManagedAgentsFileImageSource object

          Image referenced by file ID.

          • type: "file"

          • file_id: string

            ID of a previously uploaded file.

            minLength: 1

    • BetaManagedAgentsDocumentBlock object

      Document content, either specified directly as base64 data, as text, or as a reference via a URL.

      • type: "document"

      • source: BetaManagedAgentsBase64DocumentSource or BetaManagedAgentsPlainTextDocumentSource or BetaManagedAgentsURLDocumentSource or BetaManagedAgentsFileDocumentSource

        Union type for document source variants.

        • BetaManagedAgentsBase64DocumentSource object

          Base64-encoded document data.

          • type: "base64"

          • data: string

            Base64-encoded document data.

            minLength: 1

          • media_type: string

            MIME type of the document (e.g., "application/pdf").

            minLength: 1

        • BetaManagedAgentsPlainTextDocumentSource object

          Plain text document content.

          • type: "text"

          • data: string

            The plain text content.

            minLength: 1

          • media_type: "text/plain"

            MIME type of the text content. Must be "text/plain".

        • BetaManagedAgentsURLDocumentSource object

          Document referenced by URL.

          • type: "url"

          • url: string

            URL of the document to fetch.

            minLength: 1

        • BetaManagedAgentsFileDocumentSource object

          Document referenced by file ID.

          • type: "file"

          • file_id: string

            ID of a previously uploaded file.

            minLength: 1

      • context: optional string or null

        Additional context about the document for the model.

      • title: optional string or null

        The title of the document.

    • BetaManagedAgentsRedactedBlock object

      Placeholder for content withheld by Anthropic model policy.

      • type: "redacted"

  • processed_at: string

    A timestamp in RFC 3339 format

    format: date-time

  • to_session_thread_id: string

    Public sthr_ ID of the thread the message was sent to.

  • to_agent_name: optional string or null

    Name of the callable agent this message was sent to. Absent when sent to the primary agent.