I am unable to find an endpoint that will provide the mapping between lead source names and ids so I can display names to my users to choose from for lead sources, much in the way that the following endpoint provides the mapping for opportunity stages.
/opportunity/stage_pipeline
Is there an endpoint I am missing?
Not sure that REST will provide that yet (they’ve been adding to REST progressively but I think there might be more to do?).
You can use the RPC api to query the leadsource table though. You can even use the same access token to do so.
Cool, Thanks @John_Borelli
I have not even looked at the RPC api since all the docs say ‘Legacy’ 
Hopefully the REST api will be updated with this functionality, but at least now I have a work around to investigate.
The interactive documentation has the isdk and standard (oauth enabled) version. Just click the item you want (left hand item, labled ‘PHP’, in the right pane of the documentation, as in the image below:
Then on the left, select the ‘Data’ object. You can use that data object to read the tables you can find here:
https://developer.infusionsoft.com/docs/table-schema/
The data object is imaged below as well:
