Thanks. The problem is not how to integrate with an API, but how to program the asymmetry between deposit fees and withdrawal fees. With ERC20, typically exchanges bring forward the cost of withdrawal to the deposit. If I ever find the time to do something similar, I will probably do it by interfacing directly to a local eth wallet, not a third party service. My original intent with this plugin is to let people use their own wallets, and the third party services are there only as a convenience for everyone else. But at this time I do not have the time to work on this.
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