The mints won't actually decode the ecash tokens. At least for Fedimint, the lightning integration is via a "lightning gateway". These gateways are lightning nodes and clients of federation(s) and act as a market maker between ecash notes and btc. So assuming cashu can receive via lightning, a fedimint user can pay a cashu mint using a lightning gateway 👊
Discussion
LND supportifor these lightning gateways just got merged! https://t.co/uVUv6GiPJx
Thank you for sharing this.
I am just assuming that when a fedimint token is scanned on the cashu mint wallet it should know how to send an invoice to the fedimint so that it can claim the token and get the funds through lightning.
Speculating here, this is how I would have designed on the spot 🤔