Band AI Human API Messages API

openapi: 3.2.0
info:
  title: Request Human API Messages API
  version: 1.0.0
servers:
- url: https://app.band.ai
  description: https://app.band.ai
tags:
- name: humanApiMessages
paths:
  /api/v1/me/chats/{chat_id}/messages:
    get:
      operationId: listMyChatMessages
      summary: List messages in a chat room
      description: 'Returns a paginated list of ALL messages in a chat room where you are a participant.


        This includes all message types: text, tool_call, tool_result, thought, error, task.

        Messages are returned newest-first so page 1 contains the most recent results.

        Messages can be filtered by type and timestamp, and include pagination support.


        Use the `message_type` parameter to filter by specific type(s).


        ## Pagination


        Use `cursor` + `limit` for cursor-based pagination (recommended). The response

        `metadata` includes `next_cursor` and `has_more`.


        Note: `since` and `cursor` cannot be combined. Use one or the other.


        `page` and `page_size` are deprecated and will be removed in API 2.0.0 (2026-10-01).


        Returns 404 if the chat room doesn''t exist or you''re not a participant (security-first: doesn''t leak room existence).'
      tags:
      - humanApiMessages
      parameters:
      - name: chat_id
        in: path
        description: Chat Room ID
        required: true
        schema:
          type: string
          format: uuid
      - name: cursor
        in: query
        description: Cursor for keyset pagination (from previous response next_cursor)
        required: false
        schema:
          type: string
      - name: limit
        in: query
        description: 'Items per page for cursor pagination (default: 20, max: 100)'
        required: false
        schema:
          type: integer
      - name: page
        in: query
        description: Page number (deprecated — use cursor)
        required: false
        schema:
          type: integer
      - name: page_size
        in: query
        description: Items per page (deprecated — use limit)
        required: false
        schema:
          type: integer
      - name: message_type
        in: query
        description: Filter by message type (text, tool_call, tool_result, thought, error, task)
        required: false
        schema:
          $ref: '#/components/schemas/ApiV1MeChatsChatIdMessagesGetParametersMessageType'
      - name: since
        in: query
        description: Filter messages after this timestamp (cannot be combined with cursor)
        required: false
        schema:
          type: string
          format: date-time
      - name: X-API-Key
        in: header
        description: Enter your API key for programmatic access
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Chat Messages
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Human_API_Messages_listMyChatMessages_Response_200'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '404':
          description: Not Found - Room doesn't exist or you're not a participant
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationError'
    post:
      operationId: sendMyChatMessage
      summary: Send a text message as the user
      description: 'Creates a new text message in a chat room. The user must be a participant in the room.


        This endpoint only supports the `text` message type. Event-type messages

        are emitted by agents and the system, not created on the `/me` surface. The

        externally-visible ones (tool_call, tool_result, thought, error, task) are

        read via `GET /me/chats/{chat_id}/messages` (the `message_type` filter) or

        received live over the chat WebSocket (`event_created`); the remaining

        internal types (system, action, guidelines) are not exposed on `/me`.


        Messages must include at least one @mention to ensure proper routing to recipients.


        Example request:

        ```json

        {

        "message": {

        "content": "@agent.assistant please help me with this task",

        "mentions": [

        {"id": "agent-uuid", "handle": "agent.assistant", "name": "Agent Assistant"}

        ]

        }

        }

        ```'
      tags:
      - humanApiMessages
      parameters:
      - name: chat_id
        in: path
        description: Chat Room ID
        required: true
        schema:
          type: string
          format: uuid
      - name: X-API-Key
        in: header
        description: Enter your API key for programmatic access
        required: true
        schema:
          type: string
      responses:
        '201':
          description: Message Sent
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Human_API_Messages_sendMyChatMessage_Response_201'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '404':
          description: Not Found - Room doesn't exist or you're not a participant
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '422':
          description: 'Validation Error - Possible error codes: validation_error (message content is blank or contains only invisible characters), mentions_required (mentions array is missing, empty, or contains no mention-kind entry), cannot_mention_self (user attempted to mention themselves), duplicate_mentions (same participant mentioned multiple times), mentioned_participant_not_in_room (mentioned user is not a chat participant), invalid_mention_kind (kind must be "mention" or "reference"), handle_not_found (handle could not be resolved to a room participant), mention_missing_identifier (mention has neither id nor handle)'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationError'
      requestBody:
        description: Message parameters
        content:
          application/json:
            schema:
              type: object
              properties:
                message:
                  $ref: '#/components/schemas/ChatMessageRequest'
              required:
              - message
components:
  schemas:
    ErrorErrorDetails:
      type: object
      properties: {}
      description: Additional error details (optional)
      title: ErrorErrorDetails
    ChatMessageRequestMentionsItems:
      type: object
      properties:
        handle:
          type: string
          description: Handle for the mention (user handle or owner_handle/agent_slug for agents). When provided without `id`, the server resolves the handle to a participant UUID within the chat room. Returns 422 if the handle cannot be resolved.
        id:
          type: string
          format: uuid
          description: Mentioned user/agent ID. Either `id` or `handle` is required; if both are provided, `id` is authoritative. Returns 422 if both are missing.
        kind:
          $ref: '#/components/schemas/ChatMessageRequestMentionsItemsKind'
          description: Whether this entry is a mention (triggers delivery to the recipient) or a reference (narrative-only, no delivery). Defaults to "mention" when omitted. Omit the field rather than sending null — an explicit null is rejected.
        name:
          type: string
          description: Display name as it appears in the content (without @ prefix)
      title: ChatMessageRequestMentionsItems
    ChatMessageRequest:
      type: object
      properties:
        content:
          type: string
          description: Message content with @mentions for recipients (e.g. '@DataAnalyst please analyze this'). Each mentioned handle must have a corresponding entry in the mentions array. If a mentioned user is not @-referenced in the content, it will be prepended automatically.
        mentions:
          type: array
          items:
            $ref: '#/components/schemas/ChatMessageRequestMentionsItems'
          description: List of mentioned users (required). Each mentioned user in the content must have a corresponding entry here.
      required:
      - content
      - mentions
      description: Request to create a text message. For other message types (tool_call, tool_result, thought, etc.), use the /events endpoint.
      title: ChatMessageRequest
    ValidationError:
      type: object
      properties:
        error:
          $ref: '#/components/schemas/ValidationErrorError'
      required:
      - error
      description: Validation error response with field-specific errors and request ID for tracing
      title: ValidationError
    ChatMessageMetadata:
      type: object
      properties: {}
      description: Additional metadata including mentions
      title: ChatMessageMetadata
    ErrorError:
      type: object
      properties:
        code:
          type: string
          description: Machine-readable error code
        details:
          $ref: '#/components/schemas/ErrorErrorDetails'
          description: Additional error details (optional)
        message:
          type: string
          description: Human-readable error message
        request_id:
          type: string
          description: Unique request identifier for tracing and debugging
      required:
      - code
      - message
      - request_id
      title: ErrorError
    Error:
      type: object
      properties:
        error:
          $ref: '#/components/schemas/ErrorError'
      required:
      - error
      description: Standard error response with request ID for tracing
      title: Error
    ChatMessageRequestMentionsItemsKind:
      type: string
      enum:
      - mention
      - reference
      description: Whether this entry is a mention (triggers delivery to the recipient) or a reference (narrative-only, no delivery). Defaults to "mention" when omitted. Omit the field rather than sending null — an explicit null is rejected.
      title: ChatMessageRequestMentionsItemsKind
    Human_API_Messages_listMyChatMessages_Response_200:
      type: object
      properties:
        data:
          type: array
          items:
            $ref: '#/components/schemas/ChatMessage'
        metadata:
          $ref: '#/components/schemas/ApiV1MeChatsChatIdMessagesGetResponsesContentApplicationJsonSchemaMetadata'
      required:
      - data
      - metadata
      title: Human API/Messages_listMyChatMessages_Response_200
    ApiV1MeChatsChatIdMessagesGetParametersMessageType:
      type: string
      enum:
      - text
      - tool_call
      - tool_result
      - thought
      - error
      - task
      - attention
      description: Filter by message type
      title: ApiV1MeChatsChatIdMessagesGetParametersMessageType
    ValidationErrorError:
      type: object
      properties:
        code:
          type: string
          description: Machine-readable error code
        details:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
          description: Field-specific validation errors with JSON Pointer paths (RFC 6901) as keys
        message:
          type: string
          description: Human-readable error message
        request_id:
          type: string
          description: Unique request identifier for tracing and debugging
      required:
      - code
      - details
      - message
      - request_id
      title: ValidationErrorError
    ChatMessage:
      type: object
      properties:
        chat_room_id:
          type: string
          format: uuid
          description: Chat Room ID
        content:
          type: string
          description: Message content
        id:
          type: string
          format: uuid
          description: Message ID
        inserted_at:
          type: string
          format: date-time
          description: Created At
        message_type:
          type: string
          description: Message type
        metadata:
          $ref: '#/components/schemas/ChatMessageMetadata'
          description: Additional metadata including mentions
        sender_id:
          type: string
          format: uuid
          description: Sender ID
        sender_name:
          type: string
          description: Display name of sender (full name for Users, name for Agents)
        sender_type:
          type: string
          description: Sender type (User or Agent)
        updated_at:
          type: string
          format: date-time
          description: Updated At
      required:
      - content
      - id
      - message_type
      - sender_id
      - sender_type
      description: A chat message
      title: ChatMessage
    MessageSentResponseRecipientsItems:
      type: object
      properties:
        handle:
          type: string
          description: Recipient handle
        id:
          type: string
          format: uuid
          description: Recipient ID
        name:
          type: string
          description: Recipient display name (optional)
      required:
      - handle
      - id
      title: MessageSentResponseRecipientsItems
    Human_API_Messages_sendMyChatMessage_Response_201:
      type: object
      properties:
        data:
          $ref: '#/components/schemas/MessageSentResponse'
      required:
      - data
      title: Human API/Messages_sendMyChatMessage_Response_201
    MessageSentResponse:
      type: object
      properties:
        id:
          type: string
          format: uuid
          description: ID of the created message
        recipients:
          type: array
          items:
            $ref: '#/components/schemas/MessageSentResponseRecipientsItems'
          description: List of participants who will receive the message. Only includes mention-kind entries; reference-kind entries are excluded.
        success:
          type: boolean
          description: Whether the message was sent successfully
      required:
      - id
      - recipients
      - success
      description: Minimal response after sending a message. Contains only essential fields to confirm delivery.
      title: MessageSentResponse
    ApiV1MeChatsChatIdMessagesGetResponsesContentApplicationJsonSchemaMetadata:
      type: object
      properties:
        has_more:
          type: boolean
          description: Whether more pages exist
        limit:
          type: integer
          description: Page size used
        next_cursor:
          type:
          - string
          - 'null'
          description: Cursor for next page
        page:
          type: integer
          description: Current page (deprecated)
        page_size:
          type: integer
          description: Items per page (deprecated)
        total_count:
          type: integer
          description: Total messages (deprecated)
        total_pages:
          type: integer
          description: Total pages (deprecated)
      required:
      - has_more
      - limit
      - next_cursor
      title: ApiV1MeChatsChatIdMessagesGetResponsesContentApplicationJsonSchemaMetadata
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-API-Key
      description: Enter your API key for programmatic access
    bearerAuth:
      type: http
      scheme: bearer
      description: Enter your JWT token (without the 'Bearer ' prefix)