API testing is a type of software testing that involves testing application programming interfaces (APIs) directly
and as part of integration testing to determine if they meet expectations for functionality, reliability, performa
nce, and security.[1] Since APIs lack a GUI, API testing is performed at the message layer.[2] API testing is no
w considered critical for automating testing because APIs now serve as the primary interface to application lo
gic and because GUI tests are difficult to maintain with the short release cycles and frequent changes commo
nly used with Agile software development and DevOps) ————引自维基百科
接口测试的开始阶段