1.16 Maintain your APIApril 15th, 2009 — Marieke Guy
Once an API has been released it should be kept static and not be changed. If you do have to change an API maintain backwards compatibility. Contact the API users and warn then well in advance and ask them to get back to you if changes affect the services they are offering. Provide a transitional frame-time with deprecated APIs support.
“By making the API’s network aware and destination-agnostic you enhance an API’s usability.“
Logging the detail of API usage can help identify the most common types of request, which can help direct optimisation strategies. When using external APIs it is best to design defensively: e.g. to cater for situations when the remote services are unavailable or the API fails.
Consider having a business model in place so that your API remains sustainable
“Understand the responsibility to users which comes with creating and promoting APIs: they should be stable, reliable, sustainable, responsive, capable of scaling, well-suited to the needs of the customer, well-documented, standards-based, and backwards compatible.“