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There is HiveJS and DHive. Dhive was better, but isn't maintained so most people use HiveJS.

Cheers, I was looking at those, but neither seem to make much or any reference to the internal market. Or have I overlooked something?

Is there perhaps any documentation for API endpoints for the market?

Hive internal market or Hive Engine?

I've only used the internal market, so I was referring to that one.

Hive Engine is for all of the other tokens built on Hive correct?

Hive Engine is for all of the other tokens built on Hive correct?

yes

What made DHive better than HiveJS?

It had more functionality and was structured more professionally. I would recommend comparing the documentation and you will clearly see what I mean.

OK it hasn't been updated in a while, how has it fallen behind Hive.js or is out of date?
Has there been much change to the Hive API?

Almost all the Hive libraries are not really maintained much, except when there is a hard fork and there is an emergency update, someone will usually dig in and figure out what needs to be fixed.

Thanks for the clarification.