If you are looking to whitelist MessageBird's IP addresses to connect your application to MessageBird's REST API because of your application's requirement, it will not be possible to whitelist the IP range for our REST API since our IP addresses are dynamic. Our REST API platform is offered from a globally distributed infrastructure. Hence you will not be able to whitelist the IP addresses of our platform.
However, we do offer the possibility of using a signing key to verify HTTP requests. You can create a signing key via the left developer pane → API settings or by clicking here.
You can find more information on how to implement it into your API set up by checking our Verify HTTP request Documentation.
If you have any issues with this, feel free to reach out to firstname.lastname@example.org for further help!