> ## Documentation Index
> Fetch the complete documentation index at: https://docs.contactbutton.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add a conversation message



## OpenAPI

````yaml /openapi.yaml post /public/pages/{page}/conversations/{conversation}/messages
openapi: 3.1.0
info:
  title: Contact Button API
  version: 1.0.0-alpha.1
  description: >
    API-first management and public agent actions for Contact Buttons and
    button.contact pages.

    API v1 is the first public contract. Existing private legacy API and browser
    workflows remain supported.
  contact:
    name: Contact Button
    url: https://learn.contactbutton.com
servers:
  - url: https://api.contactbutton.com/v1
    description: Production (canonical)
  - url: https://app.contactbutton.com/v1
    description: Backwards-compatible application-domain alias
security:
  - bearerAuth: []
tags:
  - name: Onboarding
    description: Human-verified agent onboarding.
  - name: Workspaces
  - name: Team
  - name: Pages
  - name: Domains
  - name: Buttons
  - name: Forms
  - name: Surveys
  - name: Apps
  - name: Knowledge
  - name: Booking
  - name: Telephony
    description: >-
      Bring-your-own-Telnyx setup, call flows, phone numbers, and voice
      interactions.
  - name: Reviews
    description: >-
      Send consented review requests through workspace-owned email, SMS, and
      WhatsApp channels.
  - name: Commerce
  - name: Engagement inbox
  - name: Public actions
    description: Public, rate-limited actions that may require human confirmation.
paths:
  /public/pages/{page}/conversations/{conversation}/messages:
    post:
      tags:
        - Public actions
      summary: Add a conversation message
      operationId: addConversationMessage
      parameters:
        - $ref: '#/components/parameters/PublicPage'
        - $ref: '#/components/parameters/ConversationId'
        - $ref: '#/components/parameters/ConversationToken'
        - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              description: >-
                Provide body or the ID of a native_chat/request_human reply.
                Popup, app-widget, and URL actions are dispatched by the Contact
                Button runtime.
              properties:
                body:
                  type: string
                  maxLength: 10000
                suggested_reply_id:
                  type: string
                  format: uuid
                button_id:
                  type: string
                  format: uuid
                sender_type:
                  type: string
                  enum:
                    - visitor
                    - agent
                agent_context:
                  $ref: '#/components/schemas/AgentContext'
      responses:
        '200':
          $ref: '#/components/responses/Data'
      security: []
components:
  parameters:
    PublicPage:
      name: page
      in: path
      required: true
      schema:
        type: string
        description: Published page UUID or slug.
    ConversationId:
      name: conversation
      in: path
      required: true
      schema:
        type: string
        format: uuid
    ConversationToken:
      name: X-Conversation-Token
      in: header
      required: true
      description: Opaque participant token returned only when the conversation is created.
      schema:
        type: string
        minLength: 32
        maxLength: 128
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: false
      description: Stable 8–120 character key for safe mutation retries.
      schema:
        type: string
        minLength: 8
        maxLength: 120
  schemas:
    AgentContext:
      type: object
      required:
        - name
      properties:
        name:
          type: string
        provider:
          type: string
        identifier:
          type: string
        acting_for:
          type: string
    DataResponse:
      type: object
      required:
        - data
        - meta
      properties:
        data: {}
        meta:
          type: object
          properties:
            request_id:
              type: string
            next_cursor:
              type:
                - string
                - 'null'
  responses:
    Data:
      description: Successful data envelope.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/DataResponse'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: Sanctum personal access token
      description: >
        A Contact Button scoped bearer key. Send `Authorization: Bearer
        <token>`.

        Token abilities are enforced independently of workspace membership; both
        checks must pass.

        OAuth 2.0 authorization-code flows are not currently available.
      x-contact-button-token-abilities:
        workspaces:read: Read workspaces, teams, domains, settings, and connections.
        workspaces:write: >-
          Create and manage workspaces, teams, domains, settings, and
          connections.
        content:read: Read buttons, forms, lists, pages, booking types, and knowledge.
        content:write: Create, update, publish, and remove content.
        engagements:read: >-
          Read submissions, subscribers, bookings, callbacks, calls, reviews,
          and conversations.
        engagements:manage: Reply to and manage engagement records.
        actions:request: Request protected actions that can still require human confirmation.

````

## Related topics

- [Read a conversation and its messages](/api-reference/engagement-inbox/read-a-conversation-and-its-messages.md)
- [Reply to a conversation as its owner](/api-reference/engagement-inbox/reply-to-a-conversation-as-its-owner.md)
- [Start a conversation](/api-reference/public-actions/start-a-conversation.md)
- [Human and agent chat](/guides/chat.md)
- [Close a conversation](/api-reference/engagement-inbox/close-a-conversation.md)