API

• Documentation: Here's the documentation for the whole Flickr API. You can find here all the methods and feeds available, plus API kit details.
• Authentication: Flickr's auth flow is designed to ensure our users' accounts are safe. We require that users go to Flickr to authenticate a 3rd party application (such as yours), instead of allowing a possibly malicious 3rd party to handle the username/password. We make no exceptions. This approach supports all manner of applications, from websites, to mobile clients, to set-top boxes. Please carefully review the documentation to choose the flow that is most appropriate for your integration.
• Limits: Since the Flickr API is quite easy to use, it's also quite easy to abuse, which threatens all services relying on the Flickr API. To help prevent this, we limit the access to the API per key. If your application stays under 3600 queries per hour across the whole key (which means the aggregate of all the users of your integration), you'll be fine. If we detect abuse on your key, we will need to expire the key, or turn it off, in order to preserve the Flickr API functionality for others (including us!). We also track usage on other factors as well to ensure no API user abuses the system.
• Data Security: Don't store all user data, such as auth tokens, in a central place. Doing so creates a tempting place for hackers to target in order to access many accounts at once.
• Optimizing API queries: Search and localized calls take more CPU cycles than simple data lookups and so they may take more time to execute. Also, keep an eye out for the "extras" parameters availability in the API queries which may help reduce how many calls you need to make. Check out our Code blog for some tips, such as this post on the Standard Photo Response.
• Privacy: Every user has a default privacy setting for photos uploaded to their account. Please honor this default by either uploading with this setting or presenting it as the pre-selected option in a list of other privacy options. You can get this default via the flickr.prefs.getPrivacy API call, and please check this default daily in case the user has changed it. If your project is presenting the privacy options for a user to choose among, please use the standardized Flickr terms: Public, Friends, Family, Friends and Family, Private.
• Short-term caching: Your application can cache API results and images for up to 24 hrs to help reduce API load.
• Revoking API keys: We revoke keys for integrations that violate our API Terms of Use and our Community Guidelines. So make sure you read them carefully.
• Using the "flic.kr" shorturl: If you'd like to use a short url for a photo, you can use the native flic.kr url shortener. The format is: flic.kr/p/[short-photo-id] where the short photo id is a base58 conversion of the photo id. You can find more info and code samples on this post of the Flickr API Group.
• Requesting keys: You can request an API key here. We cannot change which account a key is handled under, so make sure you don't apply for the key under a developer's personal account since if they leave, your Flickr API key would be harder for you to control.