It's been a quick transition from app provider to API provider for photo-sharing Instagram and its Instagram API. Today the company launched a new Instagram Real-time API, which provides access to the site's content via Webhooks as photos are added that match pre-determined criteria.
In the announcement, Instagram outlines the types of content developers can get in real-time:
As of today, developers will be able to tell the Instagram API that they'd like to subscribe to new photos from four different entities:
1) Users of the developer's application: every time a user of an Instagram-linked application posts a photo, the developer's application will receive a notification. Developers like Foodspotting and sites like Dropbox now both utilize this new functionality.
2) Tags: An application can track a given tag and receive updates every time a new photo is posted with a given tag.
3) Locations: Every time a new photo is geo-tagged with a specific location, the developer will receive a notification.
4) Geographies: Sometimes individual locations are too specific. For these cases, we suggest subscribing to Geographies. Geographies consist of a latitude and longitude and a radius. This allows developers to subscribe to a given area like Austin or a specific city block of Manhattan.
Instagram's API was reverse engineered late last year by sniffing the official app's calls to the server. Later the company shut down some mashups using the unofficial API. The public beta of Instagram's official API was announced earlier this month.