Viamo Application Programming Interface (API)


Viamo is an easy, affordable, ready-to-use service for sharing information and gathering feedback through mobile interactions. With Viamo you can immediately start sending and receiving interactive voice calls, SMS messages, and USSD conversations to thousands of mobile phones, in minutes. With pre-established connections to mobile networks around the world, Viamo lets you concentrate on designing engaging content, while taking care of the technical and integration barriers for you.

The easiest way to get started with Viamo is through the web application at In addition to the web application, a complete REST API provides access to nearly all features, enabling you to easily embed interactive mobile engagement within your own applications and services.

Getting started is easy:

  1. Add subscribers
  2. Upload audio files. (Viamo can send the same content to different subscribers in different languages, so feel free to provide audio files in multiple languages.)
  3. Create a message
  4. Send out a phone call

For more powerful features, see the detailed documentation for creating Messages, Surveys (Retiring – 28 Sept. 2018), Subscribers, and Outgoing Calls. You can monitor the status of individual calls with Delivery Logs, and retrieve summarized or complete Survey Results.


All API requests must authenticate by posting an organisation’s API Key.

You can request an API Key for a new account by contacting To look up your API Key, visit

The parameter ‘api_key’ can be included as a parameter with every GET or POST request. HTTPS is used to protect the security of API keys.

The ‘api_key’ can also be posted in the header of the request

Your API Key provides full access to your organisation’s account. Please keep it secure.


Additional API calls

Check Account Credit

Method: GET



  • api_key

Returns: The organisation’s current credit balance, in Viamo credits. (1 Viamo credit = 1 USD).

{status:200, code:"2001", data:"341.02", message:"Organisation's credit fetched successfully", more_info:""}

Ping the API Server

Method: GET



  • api_key


{status:200, code:2000, data:null, message:"OK", more_info:"API Server Online at"}

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