Here are some examples of custom Prodigy recipes with custom models in the loop: Named Entity Recognition · Prodigy · An annotation tool for AI, Machine Learning & NLP There are essentially two parts your recipe needs to return: a stream of examples to annotate (a generator, so the suggestions can change as the model is updated) and an update callback that receives answers and updates the model. The specifics here depend on your model implementation: you want to choose a model that is sensitive enough to small updates in small batches, but also not too sensitive so a single decision won't throw it off. This may take some experimentation.
Also, here are some related recent threads on similar topics: