How to implement crypto payments in a project?

Question

Payment systems

Hello everyone. The situation is as follows.
I have a couple of projects on the Internet). Recently, very often, customers began to ask about the possibility of paying with cryptocurrency.
I made separate payments with a link to the wallet, but this is inconvenient, and there was a need for a complete system. Thank you all in advance.

Answer 1

If you need fiat (bucks, euro, yuan, ..):
Option A, wrong, but the easiest - go to existing payment systems (some exchanges provide this as an option), and they will automatically count and convert all deposits to your bank account , with an interface and other goodies.
Option B, correct, but the most difficult - cut your processing system, open an account on the cryptocurrency exchange for fiat (or several to spread the risks), calculate the real-time cost of cryptocurrencies (not a ticker, but a glass), more precisely, how much you can sell cryptocurrencies in order to get the required amount of fiat for each product (usually people make a ticker for themselves and multiply the cost of the goods sold by this price, but if the goods are expensive and you did not take this into account by the glass, a surprise may arise if there is not enough liquidity on the exchanges), also to the price add a commission in which you include the risks of price changes while the client makes a transfer to you.
Each deposit is a new address (or if these are cryptocurrencies with accounts, you define a unique string that will identify a specific payment, and issue it to the user for placement in a memo), as soon as an incoming transaction has arrived on your account, you make a fiat purchase on the exchange for this amount (remember, the deal should not be a limit but a market), so you get exactly as much fiat as the goods cost,... of course, for this on the exchange you will have to keep a certain amount in cryptocurrencies and quickly replenish it from the accounts to which you received translations from users.
For each payment, generate a new address (you can create a pool in advance and spin it, freeing the addresses by a timeout of several days, if the user did not pay, just warn about it). We received the transfer (we waited for the required number of confirmations), noted that the goods were sold, that's all.