Contacts Overview

What is the Contacts API?

In MainBrainer, Contacts help you store all information related to your customers – their names, email addresses, mobile numbers, date of birth, any custom information that you would like to store about them, etc. Contacts API helps you sync this contacts’ information between the MainBrainer CRM and other third-party CRMs.

Usage scenario for this API:

We understand that you might be using another CRM system for your other organizational needs. In such cases, it is important to have updated information across all your systems and databases.

The Contacts API comes in handy in such situations. It helps you sync and integrate your contacts’ information across the two systems.


To learn more about our CRM and how to use it, please feel free to go through our detailed article series on the same.

Batch endpoints

For many methods, there are batch endpoints which help you to make:

  •	GET calls that can return contacts and list details, or  
  •	POST calls that can create/update multiple contacts at once.

When using the batch endpoints to upsert (insert+update) contacts, ensure that you include the parameter webhookURL in your request body to get notified of batch updates instantly as they happen. Alternatively, you can retrieve the update status of the batch using the endpoint Get Contact batch insert and update status.

• Number of Contacts inserted along with the Contact IDs

• Number of Contacts updated along with the Contact IDs

• Number of Contacts skipped along with the Contact IDs

Contact properties

All information related to your contacts is stored as Contact properties. In addition to the default properties, you can store custom data under the custom fields.


SMSs will only be delivered to the contacts if their Contact Property – mobileOptIn has the value true. Similarly, emails will only be delivered to the contacts if their Contact Property – emailOptIn has the value true. read more about our opt-in process.


All integrations are subject to certain limits when consuming the MainBrainer public APIs. read more about these limits.