# Access Frequency Restrictions
Once you got the access token, your application can successfully call the various interfaces provided by the Linkus backend to manage or access the resources of the Linkus backend.
In order to prevent application errors from causing an abnormal load on the Linkus server, by default, each Linkus user is limited to a certain rate of interface calls, and when this limit is exceeded, the corresponding interface call will receive a error code.
The following is the current default frequency limit, which may be adjusted by the Linkus backend depending on operational conditions.
# Base Frequency
- For an API, no more than 50 calls/second;
- For an API, no more than 50 calls/second per IP;
# Special Frequency
Special settings:
- For paid APIs, the amount of calls will be configured by the system and will be explained in the interface documentation.
- Interfaces with a large I/O ratio, e.g. image uploads, see the corresponding interface documentation for details.