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OpenAPI Specification

openapi: 3.2.0
info:
  title: SMS API
  version: 1.0.0
  x-provenance:
    method: searched
    source: https://help.clickatell.com/developers-api-reference/ (OpenAPI fragments embedded verbatim in the GitBook .md twins, merged by info.title)
    generated: '2026-10-13'
servers:
- url: https://platform.clickatell.com
security:
- api-key: []
tags:
- name: SMS API
paths:
  /messages:
    post:
      tags:
      - SMS API
      summary: Send message via REST integration
      operationId: sendMessageREST_1
      parameters: []
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendMessageRequest'
          application/xml:
            schema:
              $ref: '#/components/schemas/SendMessageRequest'
        required: true
      responses:
        '202':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendMessagesListResponse'
            application/xml:
              schema:
                $ref: '#/components/schemas/SendMessagesListResponse'
  /messages/rest/bulk:
    post:
      tags:
      - SMS API
      summary: Send bulk messages via REST integration
      operationId: sendBulkMessageREST
      parameters: []
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendBulkMessageRequest'
        required: true
      responses:
        '202':
          description: Success
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/SendMessagesListResponse'
  /messages/http/send:
    get:
      tags:
      - SMS API
      summary: Send message via HTTP integration
      operationId: sendMessageHTTP
      parameters:
      - name: apiKey
        in: query
        description: Integration API key.
        required: true
        schema:
          type: string
      - name: to
        in: query
        description: Receiver number.
        required: true
        schema:
          type: string
      - name: from
        in: query
        description: Sender number in two-way integration.
        schema:
          type: string
      - name: content
        in: query
        description: Message content.
        required: true
        schema:
          type: string
      - name: clientMessageId
        in: query
        description: Client message id
        schema:
          type: string
      responses:
        '202':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendMessagesListResponse'
            application/xml:
              schema:
                $ref: '#/components/schemas/SendMessagesListResponse'
components:
  schemas:
    SendMessageRequest:
      type: object
      properties:
        content:
          type: string
          xml:
            name: Content
        to:
          uniqueItems: true
          type: array
          xml:
            name: To
          items:
            type: string
            xml:
              name: To
        from:
          type: string
          xml:
            name: From
        binary:
          type: boolean
          xml:
            name: Binary
        clientMessageId:
          type: string
          xml:
            name: ClientMessageId
        scheduledDeliveryTime:
          type: string
          xml:
            name: ScheduledDeliveryTime
        userDataHeader:
          maxLength: 2147483647
          minLength: 1
          type: string
          xml:
            name: UserDataHeader
        validityPeriod:
          type: integer
          format: int32
          xml:
            name: ValidityPeriod
        charset:
          type: string
          xml:
            name: Charset
      description: Send sms request
      xml:
        name: SendMessageRequest
    SendMessagesListResponse:
      type: object
      properties:
        messages:
          type: array
          xml:
            name: Messages
            wrapped: true
          items:
            $ref: '#/components/schemas/SendMessageResponse'
        errorCode:
          type: integer
          format: int32
          xml:
            name: ErrorCode
        error:
          type: string
          xml:
            name: Error
        errorDescription:
          type: string
          xml:
            name: ErrorDescription
      xml:
        name: SendMessagesResponse
    SendBulkMessageRequest:
      type: object
      properties:
        messageList:
          type: array
          items:
            $ref: '#/components/schemas/SendMessageRequest'
    SendMessageResponse:
      type: object
      properties:
        apiMessageId:
          type: string
          xml:
            name: ApiMessageId
        accepted:
          type: boolean
          xml:
            name: Accepted
        to:
          type: string
          xml:
            name: To
        errorCode:
          type: integer
          format: int32
          xml:
            name: ErrorCode
        error:
          type: string
          xml:
            name: Error
        errorDescription:
          type: string
          xml:
            name: ErrorDescription
  securitySchemes:
    api-key:
      type: apiKey
      name: Authorization
      in: header