Detection of abnormal application programming interface (API) sessions including a sequence of API requests

A computer-implemented method includes receiving training data including a plurality of API requests from a plurality of client devices. The method includes generating a plurality of permissible API sessions based on the training data. The method includes applying a sequence embedding technique to the plurality of permissible API sessions to generate a plurality of embeddings. The method includes applying a dimensionality reduction technique to the plurality of embeddings to generate a plurality of compact embeddings. The method includes applying a clustering technique to the plurality of compact embeddings to determine a plurality of different clusters of the compact embeddings. The method includes generating a plurality of patterns based on the plurality of different clusters. Each of the plurality of patterns is descriptive of permissible API sessions associated with a corresponding cluster of the plurality of different clusters.