The API IP restriction is a feature that allows you to impose IP restrictions on access to the Content API and Management API. It can be utilized to enhance security measures.
The IP restriction for the API is a feature available in the Business and Enterprise plans.
For details on the features available for each plan, please refer to the pricing page.
Restrictions can be set at the following levels.
Supports CIDR notation for IPv4 / IPv6.
IP restrictions at the environment level can be configured from "Service Settings" → "API IP Restrictions".

Please enter the IP addresses you want to allow access and click the "Change" button.

IP restrictions at the API level can be configured from the target API's "API Settings" → "API IP Restrictions".

After turning on "Set Individually", please enter the IP addresses you want to allow access and click the "Change" button.

The maximum number of allowed IP addresses that can be set for a single API varies by plan.
The HTTP status 400 Bad Request will be returned as a response. The message is as follows:
{
"message": "IP address rejected"
}