> ## Documentation Index > Fetch the complete documentation index at: https://help.commbox.io/llms.txt > Use this file to discover all available pages before exploring further. # Send Campaign > This API sends a WhatsApp campaign using a pre-approved template.

The request uses `multipart/form-data` and can include an audience file (`audience_file`), one or more IDs of audiences already saved in CommBox (`audience_id`), or both. The selected `stream_id` must belong to an active WhatsApp channel.
**Audience file requirements:** The CSV or Excel file must contain a `phone1` column. Phone numbers must include the full country code, for example `442079832100`. There is a 10 MB file size limit.
**Template requirements:** The template must be approved by WhatsApp, and `language_code` must exactly match the language configured for the template, for example `en` or `en_US`. For templates with input parameters, all placeholders must have values. Separate the values with a semicolon `;` ## OpenAPI ````json POST /campaigns { "openapi": "3.0.3", "info": { "title": "CommBox API", "x-logo": { "url": "https://www.commbox.io/logo/commbox_logo_large.png" }, "version": "2.07", "termsOfService": "https://www.commbox.io/end-user-license-agreement-eula/", "contact": { "name": "commbox", "url": "https://www.commbox.io", "email": "contactus@commbox.io" } }, "servers": [ { "url": "https://api.commbox.io/", "description": "Production server" } ], "security": [ { "BearerAuth": [] } ], "tags": [ { "name": "Core", "description": "

Systemwide verification" }, { "name": "Objects", "description": "

Objects are conversations between the AI Agent or the human agent and the customers, where each segment of the conversation is referred to as a Child. Every conversation must have a designated Stream – a communication channel such as Chat, Email, Text/SMS, etc., through which the conversation takes place.
The Object APIs category concentrates on a specific conversation, where the Stream is part of the identifying parameters. In contrast, the Streams APIs category, the Channel is the focal point of the request, and the objects and users are the filtering aspects." }, { "name": "Media", "description": "Converting media files to Base64" }, { "name": "AI Services", "description": "APIs that provide AI capabilities by the platform. " }, { "name": "Streams", "description": "

Streams are communication channels used in CommBox, such as Chat, WhatsApp, SMS/Text, etc. In the Streams category of APIs, the channel is the focal point of the request, and the objects and users are the filtering aspects. See the Enums Section for available channels and their CommBox code." }, { "name": "Tags", "description": "

Tags are a classification tool for summarizing aspects of the conversation or the user. It can mark the conversation to indicate a new sale or identify a customer as not interested in the product. To help manage the Tags assets, Tags can be grouped with a common identifier." }, { "name": "SMS", "description": "

Sending customers **SMS messages** (Texting) requires an initial opt-in step, which is not offered by CommBox and is the sole responsibility of the sending entity (Business)." }, { "name": "WhatsApp", "description": "

CommBox facilitates activities in **WABA** for the clients. Our platform helps clients create new templates and manage existing ones.

**Opt-in for WhatsApp**
Before sending WhatsApp messages to someone, you must first receive opt-in permission confirming that they wish to receive future messages from you on WhatsApp. This can be done using any channel your business uses to communicate with people — your website, app, email, retail location, etc.