@lanodan @lucy @hj I envision two components:
1. you can enter a bitcoin or eth payment URL into a user-defined field and pleroma will make it a real link.
2. you can enter a payment URL in a post and it will be made into a real link.
Literally all that has to be implemented is, recognition of bitcoin and ETH payment URLs, and linkifying it. No integration, no nothing, just recognizing standard links for payments. I think there is a similar mechanism to forward someoen to a Square or Paypal payment page with an amount. Maybe for Liberapay too.