I have a REST API, service X, I need customers to integrate with. However there are a lot of fields in the payload (~300) and one thing I'm finding is that some customers developers are resist to doing the work to map their data to mine which is slowing adoption.
I'd like to setup another service, service Y, where a developer can POST any payload representing their systems data and then a business user (who knows and cares about the field level mapping) can log into some kind of web interface and map the two data sources. Then that same service could apply the mapping on every incoming request and forward it to service X.
Now I know these kind of solutions are used in a lot of enterprisey integration tools so I don't want to re-invent too much of the wheel as data mapping and transformation isn't a core competency I want to focus on. I just don't even know what the class of software is call and where to start. What should I look for? What's the most off the shelf solution I can get that does this? Something self-hosted would be nice to host alongside my other services and ideally open source or a flat licensing fee.