# Client libraries
GC Notify (opens new window) was based on the UK government's notification system. Therefore, the API is also available using the clients developed by GOV.UK (opens new window).
# Before integrating the API
You will need to change the API endpoint when creating a client.
Feature differences to keep in mind
- Sending files by email is different with GC Notify
- Sending bulk notifications through the GOV.UK Notify clients is not directly supported. You can still use one if the client supports customization of the URL endpoint
- Sending letters is not available
- Receiving text messages is not available