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

# Preview a transmission from a CSV recipient list

> Validates recipients against a template's variables, creating a DRAFT transmission. No messages are sent until the draft is confirmed.



## OpenAPI

````yaml /api-reference/openapi.json post /api/v1/transmissions/preview
openapi: 3.1.0
info:
  title: iZap API
  version: v1
  description: Public REST API for the iZap WhatsApp business messaging platform.
  contact:
    name: iZap API Support
    email: suporte@izap.ai
  license:
    name: MIT
    url: https://opensource.org/licenses/MIT
servers:
  - url: https://api.izap.ai
    description: Production
  - url: https://api-staging.izap.ai
    description: Staging
security:
  - bearerAuth: []
tags:
  - name: Auth
    description: Login and token refresh.
  - name: OAuth
    description: OAuth 2.1 / PKCE authorization for third-party and MCP clients.
  - name: Businesses
    description: Business profile, hours, menus, and chatbot configuration.
  - name: Chats
    description: Conversations, messages, and template sends.
  - name: Scheduling
    description: Customers, services, providers, and bookings (Trinks-backed).
  - name: WhatsApp Templates
    description: Manage and sync WhatsApp message templates.
  - name: Transmissions
    description: Bulk WhatsApp template broadcasts.
  - name: Me
    description: The authenticated user's own profile and active business.
paths:
  /api/v1/transmissions/preview:
    post:
      tags:
        - Transmissions
      summary: Preview a transmission from a CSV recipient list
      description: >-
        Validates recipients against a template's variables, creating a DRAFT
        transmission. No messages are sent until the draft is confirmed.
      operationId: previewTransmission
      parameters:
        - name: business-id
          in: header
          required: true
          schema:
            type: string
            format: uuid
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/TransmissionPreviewCreate'
      responses:
        '200':
          description: Draft transmission preview.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TransmissionPreview'
              example:
                transmission_id: tr1a2b3c-1234-4a5b-9c8d-abcdef123456
                name: July promo
                status: draft
                transmission_type: whatsapp_template
                template_name: order_confirmation
                template_language: pt_BR
                recipient_count: 100
                valid_count: 98
                invalid_count: 2
                duplicate_count: 0
                estimated_duration_seconds: 60
        '401':
          description: Missing or invalid credentials.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
              example:
                detail: Not authenticated
components:
  schemas:
    TransmissionPreviewCreate:
      type: object
      required:
        - name
        - template_name
        - template_language
        - recipients
        - phone_column
      properties:
        name:
          type: string
          minLength: 1
          maxLength: 255
        transmission_type:
          type: string
          enum:
            - whatsapp_template
          default: whatsapp_template
        max_messages_per_minute:
          type: integer
          minimum: 1
          maximum: 200
          default: 60
        template_name:
          type: string
        template_language:
          type: string
        recipients:
          type: array
          description: Parsed CSV rows (column header -> value).
          items:
            type: object
            additionalProperties:
              type: string
        phone_column:
          type: string
        variable_columns:
          type: object
          additionalProperties:
            type: string
          nullable: true
        scheduled_at:
          type: string
          format: date-time
          nullable: true
        timezone:
          type: string
          nullable: true
    TransmissionPreview:
      type: object
      properties:
        transmission_id:
          type: string
          format: uuid
        name:
          type: string
        status:
          type: string
          example: draft
        transmission_type:
          type: string
        template_name:
          type: string
        template_language:
          type: string
        recipient_count:
          type: integer
        valid_count:
          type: integer
        invalid_count:
          type: integer
        duplicate_count:
          type: integer
        estimated_duration_seconds:
          type: integer
        scheduled_at:
          type: string
          format: date-time
          nullable: true
        warnings:
          type: array
          items:
            type: string
      additionalProperties: true
    Error:
      type: object
      properties:
        detail:
          type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: >-
        JWT access token obtained from POST /api/v1/auth/jwt/login, the OAuth
        token endpoint, or a business-scoped API token. Some
        Business/Chat/Template/Scheduling endpoints alternatively accept HTTP
        Basic credentials scoped to the business slug.

````