Open Source CRM

Every edition of 1CRM comes with the source code of the CRM system. This provides you with insight into the functionality of 1CRM and the opportunity to modify it to suit your needs. 1CRM can also be used as a platform to create CRM extensions. You can sell them, or provide them as open source software to the community.

1CRM Developer Guide

Here is your complete guide to advanced customization of the 1CRM Customer Relationship and Business Management (CRBM) System – with all-new extended content about the REST API. Learn how to interface with external APIs, develop for the 1CRM framework and package custom extensions.


1CRM provides an API (Application Programming Interface) for integrating with third-party applications such as accounting, ERP, e-commerce, self-service portals and others. With the 1CRM API, you can extract data in JSON format and develop new applications or integrate with existing applications. It may be accessed at /api.php from your URL root.

API Client Library

To make coding against our API easier, 1CRM also provides a Client Library – chunks of code that do the basic things an application needs to do in order to interact with an API. It can reduce the amount of code you need to write, ensures applications follow best practices when using the API, and makes your code more robust.

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