Flickr Web Services

Flickr is a photo-sharing community that enables users to upload hundreds of photos and tag each photo with descriptive words. Other users can then search on these tags, enabling them to find and comment on the photos of other users. Flickr's active community and addictive sharing features have attracted millions of users. Even better, Flickr exposes a rich set of web services that make the service highly hackable.

Featured Flickr Applications

1. Flickr Related Tag Browser from AirTight Interactive: An engaging visual way to explore tagged photos.
2. Color Fields Experimental Colr Pickr from Jim Bumgardner: Pick a color and adjust for brightness to find photos that are just the shade you want.
3. Photos on maps! Flickr World Map from allthegoodness.com—explore the world in this Flash application, sightseeing via latitude-longitude encoded photos; and Geobloggers by Dan Catt, Flickr photos (and more) plotted to GoogleMaps.

How Do I Get Started?

1. Get an Application ID
   To make Flickr web service calls, you must get an application key. There are no set restrictions on the number of calls your application can make.


2. Read the online documentation
   Flickr provides full documentation for all web service methods.


3. Download an SDK
   Flickr provides links to development kits, which include BSD-licensed examples and libraries for languages such as Perl, Python, PHP, Java, JavaScript, and Flash. If you are familiar with one of these languages, you might find the associated SDK to be more convenient than making direct web service calls via REST.

Using the Flickr API

Key Flickr Concepts

Whether you are using an SDK or working with the Flickr web services directly, it is important to understand a few key Flickr concepts before proceeding to develop your application.

Photos have numerous attributes such as the photo's user, taken date, upload date, list of tags, and Creative Commons license status. The Flickr APIs enable you to view, manipulate, and search on these attributes. You can also upload photos as a multi-part POST using the photo upload API.

Key methods: flickr.photos.search, flickr.photos.getInfo

Every photo has an associated user identifier. Once you have a user identifier, you can easily view information on that user and retrieve that user's photos and tags. Users can belong to groups, which in turn can manage collections of shared photos known as pools.

Key methods: flickr.people.getInfo, flickr.groups.getInfo

A tag is a short piece of text that users can attach to photos. Flickr users typically search on photos with a particular tag ("all photos with the tag cutepuppies") or photos with a particular tag that belong to a particular user ("all photos belong to jsmith with the tag campingtrip"). The Flickr API can retrieve tags for users and photos, which you can then use to construct URLs to particular photos or photo groups.

Key methods: flickr.photos.setTags, flickr.photos.removeTag, flickr.tags.getListPhoto, flickr.photos.getListUser

Although many Flickr methods perform public, read-only functions, certain methods require your application to be authenticated. For example, applications can change the upload date for a photo, but not for any arbitrary user. Flickr provides an Authentication API for applications that need to perform restricted actions.

Commercial Use

Commercial use is generally considered on a case-by-case basis at the current time. You can request a commercial key on the application form.

Character Encodings

The only acceptable character encoding for Flickr applications is UTF-8.

Rate Limit

The Flickr service has no pre-determined rate limit. However, irresponsible use may result in your application key being temporarily suspended. What's "responsible"? Keeping a local cache of information that is unlikely to change, sleep()ing between queries when doing large series of api calls, debugging your own code, that kind of thing. Keep it under an average of one query per second and you'll be fine.

Errors

Flickr methods use a list of error codes that are standard across the entire Flickr API. For example, if you use an expired API key in any method call, the method returns error 100: Invalid API Key. For a list of error codes that a particular method can generate, refer to the Flickr API documentation.

Support & Community

The Flickr API is discussed on the yws-flickr mailing list.