[wyager]

A problem I'm currently addressing that maybe someone can help with:

I'm using a BIP32 HD wallet master pubkey to generate addresses on the payment front-end. Now, the ideal payment-watching solution would be the following; it maintains a set of "active" addresses, which I can add to whenever, and notifies me whenever one receives a confirmed payment. However, I'm not sure if this exists. I would also settle for me being able to query arbitrary address balances quickly.

Bitcoin-core doesn't work because adding an address causes a rescan of the entire blockchain (as it doesn't maintain an address-indexed UTXO dictionary for all addresses), which is too slow. I think electrum-server might work. Even though I'm following the same derivation path as electrum-client, I don't think I can use electrum-client for this (because I could conceivably be attacked with hundreds of thousands of address generation requests, which I doubt electrum-client will like). I also want to ignore adderesses more than, say, a week old, which I don't think electrum-client supports.