FirstGiving maintains a searchable database of all US non-profit organizations, and also provides a secure donation pathway allowing one to contribute to anyone of them. It is the meta-charity donation gateway, sure to come as a technological boost to many charities which likely do not have electronic donation processing systems in place on the web. The FirstGiving API is only the 5th in our directory tagged charity, proving it a potentially under-served sector, technology-wise. To be precise, not all non-profit organizations are charitable, and so the user of this system should know the difference when electing to contribute his or her funds, though FirstGiving can process funds for any non-profit.
Providing this API further opens up the non-profits registered with FirstGiving to receive even more donations. The FirstGiving site already functions as an index of non-profit causes, hosting donation pages for many different causes. There are pages for the familiar races for cancer research and also simple appeals for funds from projects to benefit many different groups, such as trafficking survivors to take one example. Each non-profit is classified with a NTEE code, which helps to group the organizations into clusters. It's another data mapping use case just waiting for a slick visualization.
FirstGiving splits its API by two distinct purposes: searching for a charity & donating to a charity. An API key and secret are required for the more sensitive donation API, but the search API can be used without either. It seems a little odd that the search API returns results in JSON (or JSONP if you prefer) but the donations API responds in XML. Perhaps that will change in the future. The Donation registration process also requires a specific IP to be used. The good news is that FirstGiving has open sourced an implementation of its API in PHP on github, so if you want to work with it you won’t be starting from scratch.