LinkedIn API keys are throttled by default. The throttles are designed to ensure maximum performance for all developers and to protect the user experience of all users on LinkedIn.
There are three types of throttles applied to all API keys:
- Application throttles: These throttles limit the number of each API call your application can make using its API key.
- User throttles: These throttles limit the number of calls for any individual user of your application. User-level throttles serve several purposes, but in general are implemented where there is a significant potential impact to the user experience for LinkedIn users.
- Developer throttles: For people listed as developers on their API keys, they will see user throttles that are approximately four times higher than the user throttles for most calls. This gives you extra capacity to build and test your application.
Be aware that the developer throttles give you higher throttle limits as a developer of your application. But your users will experience the User throttle limits, which are lower. Take care to make sure that your application functions correctly with the User throttle limits, not just for the throttle limits for your usage as a developer.
To view current API usage of your application and to ensure you haven't hit any throttle limits, visit https://www.linkedin.com/developer/apps and click on "Usage & Limits".
To test your application using the user throttles, either remove yourself from the developer list of your API key or grant access to your application from a different account that is not a developer.
In addition to these specific controls on the API calls, some features in LinkedIn also have limits, so by watching the error message you get back, you can tell which limit may apply.