API management is the process of creating and publishing APIs, enforcing their usage policies, controlling access, nurturing the subscriber community, and collecting and analyzing usage statistics.
While solutions vary, the following functionality is typically found in API management products:
Gateway: servers that act as API front-end, receive API requests, enforce throttling and security policies, pass the calls to the back-end service, and then pass the response back to the invoker. Gateways often include transformation engines to orchestrate and modify the requests and responses on the fly. They can also collect analytics data, provide caching and other functionality.Publishing tools: user interface that API providers use to define the APIs and their access and usage policies, debug execution, manage API lifecycle.Developer portal / API store: community site for API subscribers that is typically branded by API providers and includes documentation, interactive API console to try the APIs, ability to subscribe to the APIs and manage subscription keys, and get support from the API vendor and community.Reporting and analytics: reports on API usage and subscriber behavior that let API publisher optimize their offering.Monetization: ability to charge money for commercial APIs.Gartner estimated API management to be $70 million in 2013 and growing at 40% a year.
According to Forrester Research, in US alone, annual spent on API management was at $140 million in 2014 and expected to grow to $660 million by 2020. By that time, global sales are expected to exceed a billion dollars.
The wide adoption of APIs led to the emergence of off-the-shelf API management products, open-source projects, and SaaS offerings.
Forrester Research includes the following API management vendors in their reports:
3scaleApigeeAxwayCA TechnologiesIBMInformaticaIntel ServicesMuleSoftSOA SoftwareTibco SoftwareTyk TechnologiesWSO2