Among the 25 finance APIs now listed on ProgrammableWeb, there are services from old and new companies, and large and small companies. For example, the venerable Dun and Bradstreet offers the Dun and Bradstreet Credit Check API, personal finance startup Wesabe offers an API and there's an API from Prosper, a peer-to-peer lending service. Overall, most current business and finance APIs fall into one of two categories: APIs from SaaS-based business administration and management services, and APIs that provide financial markets data.
SaaS Business Administration APIs
A variety of new on-demand service providers offer APIs as a means to reach and integrate with their services. For example, the Blinksale API accesses their online invoicing service. The REST API provides access to your Blinksale data, letting you create invoices using a Blinksale invoice template or one of your own creation. The FreshBooks API provides online invoicing and time tracking using your Freshbooks account. The KashFlow and NetAccounts APIs offer broader accounting capabilities, geared toward businesses in the UK and Australia, respectively.
Financial Data APIs
Looking for real-time financial market quotes or historical data? Fifteen APIs are ready to get you the data you need, when you need it. Xignite provides financial data APIs ranging from XigniteRealtime and XigniteFunds (real-time U.S. stock market quotes, and U.S. mutual fund data) to XigniteCurrencies and XigniteRates (currency and international interest rate data) to XigniteEdgar and XigniteCalendar (U.S. SEC Edgar filings and global economic calendars). The Xignite APIs feature SOAP and REST protocols, with all data returned in XML format. Once you've used one Xignite API, it's relatively easy to get started with others, since all the APIs incorporate a common design structure. StrikeIron offers a number of APIs that serve users with U.S. financial data including StrikeIron Stock Quotes Basic, StrikeIron Mutual Funds, and StrikeIron Historical Stock Quotes. The StrikeIron APIs utilize SOAP protocol and return results in XML format.
Business and Financial APIs provide excellent opportunities for developing mashups. One example is the Timepost mashup, which applies the Blinksale and FreshBooks business APIs, along with the popular Basecamp API (from 37signals) and the Harvest time-tracking API. Integration of these APIs results in a rich time tracking and project collaboration solution for small businesses.