Learning mode won’t work if you have 10 existing collections and want to create #11. We could rather have a SchemaLearningUpdateHandler so people could explicitly post documents to say /schema-guess to modify the schema. We could even have this implicit. Then the _default config would have just _root_, is and a few more, and if you want guessing you first send a number of docs to /schema-guess endpoint and then inspect in schema browser what you got. That handler could support a Parma &reset=true which would wipe the schema to start guessing from scratch.