[NavinF]

Ehh how does Coinbase deal with this? They gave me a unique deposit address for Etherium which is account based (not UTXO) and IIRC they’ve never asked me to fill out a memo field for any currency.

If you do use the memo field, how do you deal with user error when they copy-paste the wrong number? Banks have humans guessing and correcting wire transfer instructions. Both you and the user will burn a transaction fee each way if you automatically refund unknown transactions.

It’s been a long time since I’ve messed with wallet APIs, but I’m pretty sure you’re using the wrong API. There should be some way to consume a stream of (row_id, transaction) tuples. That way you’re never polling every address. Instead you deal with relevant events that affect any of your addresses as they happen (which is not very often. A whole blockchain might do 15 transactions/second and you see ~0% of that)

[ben165]

It depends on the exchange provider. I use Kraken and they provide an unique address for every costumer. But I read some Exchanges require the memo field especially for Stellar addresses.

If you use a memo field and there is an error the order won't be found in the system. In this case, you can write a script which sends the funds back to the address - fees. In this case you don't lose money and you don't need humans to interact. A more difficult problem would be if sb. sends a wrong amount. Then you have to interact with the costumer.

Yes, you're right. Polling is bad but the easiest solution. The best one would be to listen to incoming transactions and take action if a new one comes in. I'm going to use this solution if I continue the project.