View monero subaddress balance without monero-wallet-cli

Question

Is there any way to

1. get the balance of a subaddress, with only the view key (programmaticly) and no monero-wallet-cli installed? At best a js lib. Assume it is connected to an open node.
2. run the monero-wallet-cli on an aws lambda?

I know of the monero-javascript project. https://github.com/monero-ecosystem/monero-javascript

Sadly I can't run a wallet-rpc node on my own.

Answer 1

1. You cannot get a balance with a view key alone. All you can do with a view key is view incoming transactions - not get a wallet balance. To determine a wallet balance you also need a way to know what is spent. With a view-only wallet, you can import key images which will enable you to view a balance. Thus, you would first have to create a view-only wallet using the view key and then import key images.

2. For programatic access you would use the monero-wallet-rpc, not monero-wallet-cli. In theory you could run this on AWS Lambda but whichever tool/host you used, you still need access to a daemon also.