In org.hibernate.search.v6poc.backend.document.model.IndexSchemaFieldContext.

See in Search 5:

• NumericBridgeProvider
• JavaTimeBridgeProvider
• BasicJDKTypesBridgeProvider

Also, don't forget about enums, which may have to be handled differently:

• See org.hibernate.search.v6poc.integrationtest.showcase.library.model.BookCopy#medium and org.hibernate.search.v6poc.integrationtest.showcase.library.model.BookCopy#medium for tests in the showcase.
• See https://docs.google.com/document/d/16PAa__LsxyLZcbW3q1MvgyIznh4ZnCYLupbNMXKMRds/edit?pli=1#heading=h.vsfoi5og7qy0 for more advanced type matching than just "this exact class" when resolving default bridges.
• And good luck about passing the actual type to the bridge builder or to the bridge :]

Do not forget to change the implementations of org.hibernate.search.v6poc.backend.document.model.IndexSchemaFieldContext#as as appropriate.