What is an API key?

The API key is used by Bungie to measure who and what is using the API.

How do I get one?

Visit the developer portal on

How do I use it?

In a HTTP request, include the following header:

X-API-Key: your-api-key-here

Is the key mandatory?

Yes, although as of May, 2015, it is not being enforced. However, you should include one now to avoid your application breaking in the future.