Each day, the need for as well as the amount of network-based applications grows and with it the implementation of RESTful APIs. For all these APIs there is a need for documentation of the API's behavior, its benefits, how it interacts with other APIs, and its expected result. To solve this; An API specification is constructed. This is a document containing the design philosophy of the APIs and can act as a guideline for how they should be constructed. When designing API specifications it is often difficult to understand what objective quality the API document upholds.

To understand the objective quality of an API specification it must first be understood what a good objective quality is in this regard. We used static code tests (linter rules) that are mapped to three quality attributes that fit the industry's consensus of the most important quality attributes that need to be complacent for a good quality API. We then implemented an automatic process of splitting API specifications into positive and negative training data using the linter results of the rules. The resulting data is used to train our BERT model.The model will then be able to give an objective score to unseen API specifications. We then used a saliency map (textual heatmap) in order to understand BERT's decisions, which added the potential to generate new linter rules from the given results.

After testing unseen API specifications on our BERT model, we saw that it was able to generate a reasonable quality score. Although, when inserting smaller features to generate a textual heatmap, the predictions of our model were not correct, hence not making it possible to understand BERT's decisions through our implementation. This also meant that new rules could not be acquired from reviewing the BERT's result.