Missive Messages API

openapi: 3.0.3
info:
  title: Missive REST Analytics Messages API
  description: The Missive REST API allows developers to manage conversations, messages, contacts, drafts, labels, and analytics programmatically. Authentication uses Bearer tokens (personal access tokens) generated in Missive preferences. The API requires a Productive plan or higher to generate API tokens. Responses are JSON-formatted with HTTP 200 or 201 success codes.
  version: '1'
  contact:
    name: Missive Support
    url: https://missiveapp.com/help
  termsOfService: https://missiveapp.com/terms
servers:
- url: https://public.missiveapp.com/v1
  description: Missive REST API v1
security:
- bearerAuth: []
tags:
- name: Messages
  description: Create messages in custom channels
paths:
  /messages:
    post:
      operationId: createMessage
      summary: Create Message
      description: Create an incoming message in a custom channel. Used to ingest messages from external communication sources into Missive.
      tags:
      - Messages
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateMessageRequest'
      responses:
        '201':
          description: Message created in conversation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MessageResponse'
        '400':
          $ref: '#/components/responses/BadRequest'
components:
  schemas:
    MessageField:
      type: object
      properties:
        name:
          type: string
        address:
          type: string
        phone_number:
          type: string
        id:
          type: string
        username:
          type: string
    Error:
      type: object
      properties:
        error:
          type: string
          description: Error message
    MessageResponse:
      type: object
      properties:
        messages:
          $ref: '#/components/schemas/Message'
    Message:
      type: object
      properties:
        id:
          type: string
        subject:
          type: string
        preview:
          type: string
        body:
          type: string
        type:
          type: string
        from_field:
          $ref: '#/components/schemas/MessageField'
        to_fields:
          type: array
          items:
            $ref: '#/components/schemas/MessageField'
        cc_fields:
          type: array
          items:
            $ref: '#/components/schemas/MessageField'
        bcc_fields:
          type: array
          items:
            $ref: '#/components/schemas/MessageField'
        references:
          type: array
          items:
            type: string
        in_reply_to:
          type: array
          items:
            type: string
        attachments:
          type: array
          items:
            $ref: '#/components/schemas/Attachment'
        created_at:
          type: integer
          format: int64
        updated_at:
          type: integer
          format: int64
    Attachment:
      type: object
      properties:
        id:
          type: string
        filename:
          type: string
        extension:
          type: string
        media_type:
          type: string
        sub_type:
          type: string
        size:
          type: integer
        url:
          type: string
        width:
          type: integer
        height:
          type: integer
    CreateMessageRequest:
      type: object
      required:
      - account
      - from_field
      - to_fields
      - body
      properties:
        account:
          type: string
          description: Custom channel account ID
        from_field:
          $ref: '#/components/schemas/MessageField'
        to_fields:
          type: array
          items:
            $ref: '#/components/schemas/MessageField'
        body:
          type: string
        subject:
          type: string
        external_id:
          type: string
          description: External message identifier for deduplication
        attachments:
          type: array
          items:
            type: object
            properties:
              filename:
                type: string
              base64_data:
                type: string
  responses:
    BadRequest:
      description: Bad request — invalid parameters
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Personal access token generated in Missive preferences. Format: Bearer missive_pat-[token]. Requires Productive plan or higher.'
externalDocs:
  description: Missive Developer Documentation
  url: https://missiveapp.com/docs/developers/rest-api