Yes, Meltano has the concept of "Inline Stream Mappers". The way how to invoke those Stream Mappers depends on whether your tap is built with the Meltano SDK or not. Meltano SDK taps can run the stream mapper as part of their own invocation. All other taps need to rely on the
meltano-map-transformer
. Documentation for this feature is available here:
https://docs.meltano.com/guide/mappers