The Flickr API is available for Commercial & Non Commercial use by outside developers and Flickr users. Flickr API can be used to configure your application on different platforms and applications like Android Phone Apps, Web Applications, Various Plugins & Extensions. Apps use your Flickr API key to fetch information from your account, get you photo stream, photo albums and your photo collection.
Here we get the answer of this qestion that how to get Flickr API Key. And here is the set to get Flickr API Key:
Open the below link to get your Flickr API Key. Make sure you are already logged into your Flickr account before going to click on below link.
Link is: https://www.flickr.com/services/api/misc.api_keys.html
Link will redirect your to Flickr API Key apply page.
Click on “Apply for your key online now” link same as below screenshot.