November 2021 update: grin payments are currently not being accepted. My payments code broke, and since grin payments were never very common, it hasn't been a priority to fix it.
I'm super excited about
grin. All past altcoins have been just Bitcoin with a few bits tacked on;
occasionally these extra bits are useful/interesting (eg. Monero or Ethereum), but in the vast majority of cases this extra stuff is just meaningless marketing-oriented garbage. But grin is packed full of useful innovation from top to bottom; moreover, it's clearly built in the same cypherpunk spirit that Bitcoin was: increased freedom/sovereignty through technology.
Therefore, I'm happy to announce that the forum is now accepting grin payments automatically, probably the first site other than exchanges to do so. You'll find a link at the bottom of the evil-fee and
copper-membership pages.
grin is new and clunky to use. I don't expect many people to use it, honestly. But I needed to rewrite the forum payments system anyway in order to support LN in the future and to fix some longstanding issues with the old code, so adding grin support worked out nicely.
I don't recommend buying or not buying grin. Due to its emission schedule, I'd guess that its price will have a general downward trend for quite some time, but who knows. Currently I own zero grin (though I will be buying from the forum all grin obtained), I was not paid to add grin support, and in fact not a soul knew that I was going to do so. grin support might be removed later if it dies off or becomes too time-consuming for me to maintain.
I tested this with grin's floonet (testnet), but not mainnet yet since I don't have any grin. Hopefully it works.
A few observations I had while implementing this:
By default they want you to essentially pay to IP addresses. This was stupid when Satoshi tried it 10 years ago, and it's stupid now. At the very least you should strongly encourage (ie. nearly force) people to give out public keys along with their IPs, since otherwise MITM attacks are trivial. Even then it sucks to require the recipient to run an open-to-the-Internet server at all. And for goodness' sake, don't use the broken/centralized HTTPS system; the Bitcoin Core devs have been going to a lot of trouble trying to
remove that garbage from Core.
A better protocol for the copy/paste method is needed. For one, you shouldn't have to use intermediary files. I was annoyed when I did
grin wallet send -m file -d - and it actually created a file called "-" instead of writing to stdout like it should.
grin needs to be much better at handling transactions that never continue beyond the first or second step in the three-way transaction process. They probably shouldn't even show up in the main transaction log.
Currently I think that there's no way for the recipient to get the modified slate after running
receive the first time (eg. if it gets lost), which is nuts. And currently there appears to be no reasonable method for proving that you sent a transaction.
