With the Freesound API you can browse, search, and retrieve information about Freesound users, packs, and the sounds themselves of course. You can find similar sounds to a given target (based on content analysis) and retrieve automatically extracted features from audio files, as well as perform advanced queries combining content analysis features and other metadata (tags, etc...). With the Freesound API, you can also upload, comment, rate and bookmark sounds!
In order to use the Freesound API you need to be authenticated with an API key. You can manage your existing API keys or apply for a new one in the following url http://freesound.org/apiv2/apply (Freesound login is required).
The API documentation describing offered functionalities and examples can be found here. We have also implemented client libraries for a number of programming languages that provide an even easier way to access the Freesound API.
If you need more help after reading the documentation or want to stay up to date on any changes or future feaures of the Freesound API or if you would like to request more features for the API, please use our google group: http://groups.google.com/group/freesound-api. Freesound API usage is free for non-commercial use, but it can also be licensed for being used in commercial applications. You can find the terms of use for the Freesound API here.
Freesound is an open-source project and we will be very happy to get more people involved in its development! We coordinate all development on Github and welcome pull requests!!