TL;DR - I have an idea for a P2P decentralized marketplace using Monero and Nostr, but I'm looking for feedback and help.
So I'm a web developer that works mainly in Python (Flask), and I believe in Monero. I recently had an idea to make an open source P2P marketplace. Basically, this would work like Nostr (or on the Nostr protocol) where everything is decentralized, allowing each individual merchant to be responsible for their own legality. Payments wouldn't be handled by the marketplace. All that it would do is display the seller's receive address or qr code, and then check if the payment came through in full. So the seller would need to provide their receive address and view key which would be stored locally on the seller's computer. Once the payment is received, the marketplace would mark the order as confirmed and the seller would be responsible for fulfilling the order. I could even automate the release of digital goods on confirmation.
Since there is no way to really enforce that sellers are legitimate with this idea, there would need to be some kind of review system, like what LocalMonero.co has. Basically you can rate a merchant if you have bought from them before. People who cheat the system would drop in rankings and be avoided, while good sellers would move up in discoverability. And all merchants would be discoverable in the home screen via search or browsing. You could also subscribe to favorite merchants.
In my mind, this marketplace would solve a lot of problems at once. First off, it would make a decentralized place to buy and sell goods in private. This adds liquidity to Monero and gives us all a way to use our Monero for goods that we actually want to receive. Making the on boarding to this app super simple would allow it to basically function like a P2P amazon or ebay. The more people that sign up, the more things we have available. Merchants can be businesses or individuals.
Another thing it solves is onboarding to Monero in general. Instead of having people buy their Monero, they can get a wallet app on their phone, make a merchant account as quickly as you can sign up for a Nostr account, and sell something for Monero. No CEXs, just exchanging goods for digital cash. Want more Monero? Sell some more stuff? If it gained enough traction, it could easily attract more people to Monero as well.
This has even been done before, but it is on the Lightning Network and requires you to set up a lightning node, from what I can tell. It's not as easy as scanning a qr code to send money to someone for a good. Still, it's worth checking out. Here's the code: https://github.com/lnbits/nostrmarket, and here's a demonstration of it: https://www.youtube.com/live/2NueacYJovA?feature=share&t=6846
I'm posting this all here for two reasons. First, I wanted to know if this makes sense to anyone else. Does this sound like as good of an idea to others as it does to me? Is there anything I am missing? Has this been done before with Monero or is it being worked on by anyone else? I know of MoneroTalk's XMRBazaar, which was part of the inspiration for this, but from what I remember, that was going to use mediators to facilitate transactions, which is more overhead than I am thinking is necessary.
The other reason I bring it up is to see if others are interested in helping (or taking the idea and building it themselves before I can). I am inexperienced in coding around Monero as well as Nostr. I'm not afraid of the Monero part. That sounds pretty straightforward, especially with the python-monero package. The Nostr stuff might take me a while to figure out though. And since this seems like such a good idea to me, I'd rather tell others about it and maybe get a workable version sooner than keep it to myself. So if you'd like to help or run with this idea, go for it.
I was actually looking to avoid escrow or any of the complicated parts of money handling. My plan was just to click buy, scan the qr code with your own wallet (separate from the marketplace), and then send the funds. The marketplace wouldn't touch any crypto, and would only interact with it by checking if the funds came in on the seller's client. That would make it super easy to onboard new sellers and buyers and keep legal stuff completely on the buyers and sellers.
That wouldn't be that useful to people. All it takes is one or two people scamming and the reputation of the platform (if you can even call it that) is gone. People won't use it for long without escrow.
If you think avoiding escrow will shelter you from defending yourself in court you're wrong. If you run a web UI for your system for example, and it's the first UI so it's the most popular, and people get scammed, you're looking at lawsuits. You might win those lawsuits, but it still costs money to win a lawsuit.
I wouldn't be hosting or running a marketplace though. My plan is to write the code to make it possible for each individual seller to host/run their own shop that is accessible by anyone else running the same code. The code will be open source, so I'm not sure how I could be sued for any of that. My only involvement would be writing the code.
That also mitigates the problems with a centralized marketplace gaining a bad reputation. Some sellers will definitely cheat the system and those sellers will get a bad reputation, but that is true of anything on the internet. Any website can sell stuff and steal from you technically. Many don't though because they don't just want the money from your purchase, but also from all future sales.
Well, I'd say so long as you don't run a web app that is a frontend UI for it you can't be accused of running a marketplace. Sounds to me like you're trying to make something like OpenBazaar without escrow and with XMR as a main currency.
Also bear in mind, the things you take for granted today may not he the case tomorrow. Today we are very clear headed about this kind of thing. You can write code and as long as you're not running a service you can't be liable. But the way things are going, you've got the US government trying to classify "custodial wallet providers" as financial institutions, you've got the EU trying to make open source developers liable to their users for bugs, it seems to me the governments of the west are trying to take away our ability to just create things and give them to the world to empower them, trying to normalize this idea that if you create something you're responsible for how people use it. You may wake up one day and find that a law somewhere makes even publishing your code bad for you.
I'm not saying don't do it. Do it. But I'm saying be clear on the potential outcomes.
Avoiding escrow isn't really possible unless you somehow live in a perfect world without bad actors. I recommend doing some digging into how different defunct darknet markets have utilized escrows and monero as even if your market does everything legally there's still valuable leasons to learn. If you want recommendations you should look into White house market (mods it's defunct) as their system handled escrow in a way where everything happened at the transaction level meaning the only coins that could be stolen were the exact transaction ammount.