Bitcoin Forum

For the past few months I have been accepting Bitcoin (via Bitpay) on my site at http://www.cheapflowers.com . I would now like to also accept all the major cryptocurrencies, such as the 200+ traded on Cryptsy.com. I would use the Cryptsy API to automatically give the customer a price quote for their order, and then once they pay I would use the API to automatically liquidate the altcoin for me. The only part I am not sure about is how to handle the payment address (wallet) for each altcoin. It seems like a huge pain in the neck for me to create 200 different wallets, and then monitor them for deposits from customers (just because a customer creates an invoice in my shopping cart does not mean they actually paid it, and that the payment is valid, so I need to verify the money was credited to me).

Instead, it seems a lot easier for me to give the customer my Cryptsy generated payment address for each currency, and then their is no need for me to have my own wallets. The only problem is that I would need to track each payment received in my Cryptsy account so I could associate it with the invoice in my shopping cart that went with. Is there any way to do that? I have used Cryptsy.com, but I have never used their API. Also, if needed I could use a different exchange.

- Eric
   

top 200?
Most of them do not have deep enough market, maybe hand selected 15?

Great! I'll check out the site!



Ugh, now you've lost me.



Bingo! You've just stumbled on EXACTLY why it doesn't make much sense to have more than one or two (really one) currency constructs which do exactly the same thing!

is coinpayments.net an option ?

Interestingly, I happened to read about coinpayments.net a few minutes after I made this posting. So, I signed up and gave it a try, but I don't think it is what I am looking for, even though it is very close. I have not talked with anybody at coinpayments.net and maybe I am wrong about how it works,  but I see 2 major problems with it:

Problem #1: Coinpayments.net quotes a list of estimated currency conversion prices at https://www.coinpayments.net/supported-coins and I assume what they do is instantly liquidate the currency on an exchange (like Cryptsy.com) using an API. The problem is that when they create an invoice for the customer they base the conversion rate on the last sale price, which is meaningless for large transactions (like on my CheapFlowers.com site, most sales are $40-$100). To handle a $40 sale of Catcoin for example, their quoted price is 0.00001452 BTC (this is close to the last sale price at Cryptsy.com), but the actual price it would sell for on Cryptsy would go down to 0.00001220 because the quoted price is almost always for a very small trade amount (see the Buy bids in the order book at Cryptsy at https://www.cryptsy.com/markets/view/136), which is a price 16% lower than what Coinpayments.net quoted the buyer on the payment page.  So, it seems like for anything other than the top 4 or 5 most liquid altcoins, the merchant is losing out with this system. It is not that coinpayments.net is making money from this part, as their profit is only the .50% fee they charge, but it seems to be a bad deal for merchants. Nowhere on the site does it say exactly how the payments work in regards to the currency exchange, so I would think most merchants don't understand this risk. I don't think coinpayments.net is doing any of this on purpose, it is just how the site is setup, since any other way would be much much more complicated.

Interestingly, they give the merchant the option of providing their own wallet address for each cryptocurrency instead of having it go to coinpayments.net. They recommend using Cryptsy deposit addresses so you can use the Cryptsy auto-sell feature automatically sell any deposits that come in. That makes it much easier for the merchant, but still does not solve the currency conversion loss problem.

Since the Coinpayments.net site does not explain how the currency pricing conversions work, I decided to do an experiment. I used their merchant tools to create 2 test invoices, and then I tried paying them (like a customer would) using Catcoin:
$1 invoice - It told me to send 121.03556800 CAT
$100 invoice - It told me to send 12105.00575900 CAT

It is a little complicated to try to figure out the Coinpayments.net conversions, because just like Cryptsy does, they convert all the altcoins to BTC, but I used the current Bitcoin bid price from btc-e.com of $565.60 USD, and the Coinpayments.net quoted rate of 0.00001452 BTC for Catcoin and got these results of how much I would get as the merchant (before fees):
$1 invoice - $.9940
$100 invoice - $99.41

So, it seems like I am figuring out everything the same way coinpayments.net does, since both of the USD conversion rates almost exactly match the $ amount of the invoice. That is good so far, since it means they handle it exactly the way I think they do.  Here's the problem with their system though.  When I looked at the order book in Cryptsy, even to sell $1 of Catcoin had a much lower price than the last sale price, so here's what I would have actually received as a merchant through coinpayments.net:
$1 invoice - Cryptsy bid of 0.00001315 BTC =  $.9002
$100 invoice - Crypsty bid of 0.00001220 BTC = $83.53

This is a problem because if I knew I was going to lose so much on the conversion, I would have quoted the customer a much higher rate. Coinpayments.net does have a feature that lets me charge a percentage extra for each cryptocurrency, but it would a lot of work for me to estimate the average markup I would need for each of the 52 currencies they offer, plus that markup is very dependent on the amount of the sale so there is really no way to estimate it.

Problem #2:  The other problem with their system is they give the customer 4 days to pay the invoice. If the altcoin shoots up in value during those 4 days, the customer will cancel the invoice and not pay, but if it stays the same or crashes they will pay, so there is only downside risk for the merchant with fluctuating exchange rates. For comparison purposes, Bitpay.com give customers only 15 minutes to pay their Bitcoin invoice.


- Eric

I don't see why you want to accept so many different coins. As you've shown, they're not very liquid. If someone wants to buy your product but only has, for example, DoorknobCoin (I hope that's not a thing), they can trade it for a more stable coin pretty easily.

It is good publicity for my site to accept as many altcoins as possible. That way I get listed in many different directories. Isn't the goal of these altcoins that they want as many sites as possible to accept them? Also, doesn't the owner of a "DoorknobCoin" want to actually spend it instead of going to an exchange and converting it?

just looking at C-cex.com today they also offer a merchant feature... you may want to check them out..

Thanks, C-cex.com is interesting.  They have a checkered past (see https://bitcointalk.org/index.php?topic=418700.200) but they seem to be doing ok now, so I signed up.
Their merchant program (https://c-cex.com/?id=merch) is easy to use and much better than nothing (which is what the other exchanges offer), but it seems too unsophisticated for what I need. I created a demo page to test it and had it working in under 1 minute, but it has some problems.  Mainly, it uses a fixed value for the altcoin in the form, which you need to set yourself when you put the form on your site. So, it is not tied at all to the changing market price of the altcoin in BTC or USD. It is just card coded like:
<input type="hidden" name="coin" value="doge">
<input type="hidden" name="amount" value="1.122">
and it then generates a page on the C-cex.com server that tells the customer how much to pay and gives them a payment address:
------------------------------------------
Please, send 1.122 DOGE to this address:
DCiChRa8SW1cMQ458fRMH9naSRTPiJxFeG
------------------------------------------

So, I would need to use programming to make the value of the altcoin dynamic based on the market price using their API, and if I am going to do that, I might as well just setup my own form using their API. Their form also requires each sale to have a unique purchase ID, or otherwise the form won't work (it gives a duplicate ID error). So again, if I am going to have to use programming to generate a unique sale ID, then I might as well do it all myself. Plus, it has an IPN type notification system to let me know that the customer's payment was completed. Their is no way around all of this stuff, so it is not their fault, but it is not as simple as just putting their payment form on your site.

An even bigger problem than all of this though is that unlike with Cryptsy.com, there is no way for me to automatically liquidate the payments when they come in. If a customer pays in Doge, it stays in Doge in my C-cex.com account until I manually convert it to BTC. I could use the API to automatically convert it, but I could do that with the API from any exchange.

- Eric

the more currencies then better - even just as advertising for you.

Actually, it makes sense to save potential customers the extra step they would need to take to convert their crypto into Bitcoin before buying on your ecommerce site. Remember, most exchanges have a trading fee and it means less cost to the customer to be able to buy from you using, say, Mintcoin without having to exchange it first. Anyhow, a lot of the sales I've made involving cryptocurrencies are people who might have been looking for something I'm selling about forever and, now that they've found it, they don't want to hassle around with the exchanges before they buy.

After reading through the entire thread. I didn't see a definitive answer as to which site can provide the service you're looking for best.

A bit of info before beginning......
I'm an Aussie.
I live in Siberia currently.
I have a website where I sell eProducts, The server is located in the USA.

I signed up with coinbase.com to start developing a payment integration system to accept payments on my site.
They have a few different versions of their API which made it difficult to do.
Not only that, when you access their site, they wont let you do anything if your "located" in Russia or any of the countries in their list.
It seems they're still living in the 19th century.

after lots of messaging, they finally told me that they support ONLY people with valid USA Id's..... ok, scratch coinbase form my list.

Next I came to coinpayments.net
lots of sample code.
so I figured out some nice little things I can do.
I get from my eStore, the amount in USD.
I ask the client what currency they want to trade.
I do a conversion request and show them that  the price in the their selected currency is x.xxxx and a button to click
When they click, they are send to coinpayments.net to a custom payments page that lists ALL the currencies that I want to accept and there are a LOT of them. Even paypal is on their list.

Yeah, I may lose a few percent in the trade and conversions, but it's better that not even getting the sale. 80% is better than 0%

So, now that I've figured out the sample code, I can start the integration script for real.

This is just an overview of my experience.