API is the abbreviation for an application programming interface.
In simple terms it is an “electronic handshake” between two systems.
This electronic handshake defines a “common language” for the systems to talk to each other. In the world of commercial real estate (CRE), it is most commonly used to pass data between two systems.
As with any formal relationship, the API’s documentation is very important. The documentation generally lists the fields, and indicates what minimum required information is required to pass a message. So ensuring that each party does not have to understand the intricacies behind each system.
A good API will also provide detailed feedback in the event that the wrong data is passed.
API documentation should also be “version controlled” – for example: one this day, the API changed, and these were the changes.
It is a bad practice to make breaking changes to an API (for example adding required fields) without letting the partners to the API know ahead of time