Methods, systems, apparatuses, devices, and computer program products are described. A mocking service may log a set of real application programming interface (API) data including a set of API requests and corresponding API responses. Using a generator function of a generative adversarial network (GAN), the mocking service may generate a set of sample (e.g., mock) data that mimics the API requests and responses. The mocking service may use a discriminator function to compare the sample data to the real API data and weight parameters of the GAN (e.g., retrain a machine learning model of the GAN) until the generator function generates sample data similar enough to the real API data. When the discriminator function is unable to distinguish the sample data, the real data, the mocking service may store the trained GAN and use it to generate mock API responses to API requests from users.