Bitcoin URI Protocol Scheme

[Pmalek]

You can use a simple code to receive a payment from someone else, where that person only needs to click on a link to automatically fill out the transaction information.
The imported info includes the destination address of the payment, the amount, and a description (optional).

The code looks like this:

Code:

bitcoin:bc1qc8qk228490dwvfcrpzmnx8c2p7sh0k2e72tg78?amount=10&message=payment

- After "bitcoin:" you enter the destination address.
- After the address, the code must include "?amount=" followed by the amount in BTC.
- If you don't want to add a description, delete the part of the code the follows the amount you entered. The code would then look like this:

Code:

bitcoin:bc1qc8qk228490dwvfcrpzmnx8c2p7sh0k2e72tg78?amount=10

If you are using a crypto wallet that supports Bitcoin payment URIs, copy and paste the code into your internet browser (works both on Chrome and Firefox), and you will initiate the transaction generation process.
If you are posting this on Bitcointalk, you can modify the URL with a hyperlink. Here are two examples of how it can look:

Click here to send the funds
Pay 0.25 BTC by clicking on this link

Many popular wallets support the URI scheme. Here are just some that I know of:

• Electrum
• Bitcoin Core
• Armory
• Mycelium
• Trust Wallet
• Copay
• Edge
• Exodus
• Coinomi
• BlueWallet
• Blockchain.com Wallet

     

*Source of the info is this post by pooya87 here.

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[bL4nkcode]

More info - this Bitcoin URI protocol is the one also used in many supported wallet (I guess most of these bitcoin wallets) when sending/receiving via QR code instead of clicking links, mainly for receiving bitcoin with amount and message which are optional.

[Charles-Tim]

This URL can be generated while making transaction, just like on Electrum wallet, by filling in the exact amount of Bitcoin and also filling in the description on the receive page will generate the QR code and URL for the transaction. But one thing I still consider is that irrespective of the way Bitcoin wallet user want to make transaction, he should be very careful of clipboard and QR code malware, to check and recheck the address he want to send to very well before making any transaction because I think this URL means of payment will not be resistant against such malware. And also we should be very careful of malware in general, making our device safe from any form of malware that can result to coin lost.

[coupable]

If you run a business and want users to pay with bitcoin, then this URI is a great feature to help custmers pay without the need to fill transactions details with receipping address and amount... Something similar to invoices when you add a paiement gate from BitPay or Coinpaiement .
However, i think it's not an option that can be used by newbies and less-knowledge people when it comes to regular transactions and P2P operations; This will open the door for thiefs and scammers to decieve ignorant people .
Better for newbies to manually fill the transaction details and carefully re-check those info before sign to broadcast .

[Upgrade00]

I'm curious on something about this URL. Would it modify the settings on my own wallet? For example, if I set my default denomination to mBTC and someone create a transaction in BTC, would it readjust on my end, or remain as mBTC?

Better for newbies to manually fill the transaction details and carefully re-check those info before sign to broadcast .

It's actually better for everyone to manually fill the details and double check (and double check again) before clicking send. Scanning QR codes make the process much easier and the rest isn't much of a hassle.

[Charles-Tim]

I'm curious on something about this URL. Would it modify the settings on my own wallet? For example, if I set my default denomination to mBTC and someone create a transaction in BTC, would it readjust on my end, or remain as mBTC?

It will not, neither can it affect the denomination that you set on your wallet, if the other party have it on his wallet set as BTC, that does not mean it will change on your own wallet, if you set it in mBTC, the BTC amount set by the other party will be displayed as mBTC that you set on your wallet and get the same amount but different denomination.

[witcher_sense]

Bitcoin URI is definitely a convenient tool that facilitates user's interactions with the bitcoin network. However, I don't think that this solution is suitable for complete newbies who have never dealt with payments on the network. First of all, it damages the privacy of both senders, who use the link, and the receiver, who posted it, it encourages a bad practice, which is address reuse. It is good for a one-time payment but doesn't work for donations. Secondly, not all wallets are supporting this kind of link, which may confuse inexperienced users and force them to try different wallets or options. Thirdly, hyperlinks are dangerous by themselves. A nefarious actor can easily hide a link to malicious software or phishing website behind what will look like a normal bitcoin URI. Also, a hacker can simply change the posted address with his own using hyperlinks, and no one will ever notice. It may well be I am exaggerating and there is no issue at all with these URIs but when it comes to newbies and all the ways they could be deceived it is impossible to foresee all outcomes.

[Pmalek]

I think this URL means of payment will not be resistant against such malware.

Good point and it got me thinking about the same thing as well. I am really not sure whether a clipboard hijacker would be able to change the address if you just clicked on it and it automatically filled up the payment details as is the case with this URI scheme. Does anyone know for sure?

Better for newbies to manually fill the transaction details and carefully re-check those info before sign to broadcast .

Everyone should double check where and how they are sending their coins irrespective of if you do it manually or it gets automatically filled. Just check that the destination address matches the one you need to send to after clicking on the link and you will be fine.

I'm curious on something about this URL. Would it modify the settings on my own wallet? For example, if I set my default denomination to mBTC and someone create a transaction in BTC, would it readjust on my end, or remain as mBTC?

I just tried it with the links in OP on Electrum. When I have my base unit set at BTC, the displayed amount to send is 1.4 BTC. When I change it to mBTC, it shows 1400 mBTC instead. It will show the amounts in whatever unit you selected for yourself. 

[Charles-Tim]

Good point and it got me thinking about the same thing as well. I am really not sure whether a clipboard hijacker would be able to change the address if you just clicked on it and it automatically filled up the payment details as is the case with this URI scheme. Does anyone know for sure?

So far the URL will still necessarily fill in the appropriate space that should have been filled manually, this will not be resistant against clipboard malware in my opinion. Just as you commented, anytime someone want to transfer bitcoin to another address, the person should check and recheck the address before sending.

[bL4nkcode]

Btw I have tried the URI on blockchain.com mobile wallet but it wont work while it actually fine when using with trust wallet, electrum and coinomi, both mobile wallets.

Also, it doesn't work on wallets that didn't support wallet address such the both segwit format address, which is obviously the case.

[Welsh]

Also, a hacker can simply change the posted address with his own using hyperlinks, and no one will ever notice. It may well be I am exaggerating and there is no issue at all with these URIs but when it comes to newbies and all the ways they could be deceived it is impossible to foresee all outcomes.

While this is true, if the hacker has got access to change that address, they likely have the capability of tricking someone to send to their address through other means too. I don't think there's a particularly higher risk of address changing just because it's a hyperlink. Okay, theoretically is does have more attack vectors based on being public, and therefore potentially someone could compromise either the user or the forum, and change the address instead of just compromising the user, but the risk of that would be relatively low. Especially, for low level targets. This would be more appropriate for theymos, satoshi, and various other high level users on the forum.

It may well be I am exaggerating and there is no issue at all with these URIs but when it comes to newbies and all the ways they could be deceived it is impossible to foresee all outcomes.

Nope, this is just something that the majority of people ignore, especially when it comes to teaching people about a new thing. My general advice should be; teach everyone to the standard expected, and from a learners perspective learn from the start how you intend to carry on. So, for lack of good phrasing there; learn good protocols at the start, and then you don't have to deviate, and learn more things in the future, which would potentially increase the complexity due to mixing different methods up.

If you are taught to check the Bitcoin address three times, and unless there's a significantly better approach available, that you wasn't aware of at the time of learning, then you should continue doing so. I don't think it's a good idea to teach people about URLS unless they have a specific use for that, otherwise they'll like it because it's pretty gimmicky, and then they'll use that everywhere which wouldn't be appropriate.

[pooya87]

First of all, it damages the privacy of both senders, who use the link, and the receiver, who posted it, it encourages a bad practice, which is address reuse. It is good for a one-time payment but doesn't work for donations.

No it does not. This scheme is simply giving an option to turn the address string into a clickable link. For example when you go to a merchant's website and they create a new address for you to pay they represent you with the string which you have to copy and then paste in your wallet. Then you have to do the same with the amount (since it is never a round number, something like 0.00167894).
Using this scheme you simply click the link and the appropriate fields in your wallet will be filled which you can double check later.

Same with donations, the address is already being reused for donations. This way you simplify the donating process a bit.

Secondly, not all wallets are supporting this kind of link, which may confuse inexperienced users and force them to try different wallets or options.

Not a big deal because when they click it and nothing happens they can simply copy the address and manually handle payment.
For example the merchant's website can have a little tooltip telling them their wallet may not support this but the URI is the "easy way" and otherwise to copy the information themselves.

A nefarious actor can easily hide a link to malicious software or phishing website behind what will look like a normal bitcoin URI.

Someone dealing with a "nefarious actor" is in a lot more danger than clicking a fake link!

Also, a hacker can simply change the posted address with his own using hyperlinks, and no one will ever notice.

I'm not sure if this is possible because for example all the example links you see in OP are protected by bitcointalk's SSL encryption and can not be changed by a MITM attack. And unless the user has a malware on their own system I don't see how else the address could change and if they do have a malware they have more things to worry about.
However there is still BIP-70, BIP-71 and BIP-72 describing solutions to the problem you are talking about.

[Pmalek]

Btw I have tried the URI on blockchain.com mobile wallet but it wont work while it actually fine when using with trust wallet, electrum and coinomi, both mobile wallets.

Thanks for testing that. I wonder why it doesn't work on blockchain. I am sure I remembered correctly that it used to work even with blockchain's wallet.

I will add Trust Wallet and Coinomi to the list of wallets that support the URI Protocol Scheme and I will remove Blockchain.
If anyone else knows any other good wallets where it works, feel free to mention it. But please test it before you do, so we can avoid spreading misinformation.

[Charles-Tim]

I will add Trust Wallet and Coinomi to the list of wallets that support the URI Protocol Scheme and I will remove Blockchain.
If anyone else knows any other good wallets where it works, feel free to mention it. But please test it before you do, so we can avoid spreading misinformation.

Trustwallet and Coinomi are both close source wallets, I think if you will have to include close source wallet, it has to be indicated, although you can do it as you which but just the way I think it should be. Close source wallets are the worst wallet that could be use as an attack in the future, this is the reason I do not even like mentioning close such wallets at all.

[khaled0111]

Thanks for testing that. I wonder why it doesn't work on blockchain. I am sure I remembered correctly that it used to work even with blockchain's wallet.

Blockchain wallet app supports URIs and here is a screenshot from my mobile after clicking on one of the links from OP:

If the blockchain wallet is empty, it won't open the send tab and fill up the fields. It will briefly display an error message stating that you don't have enough balance.
I suppose bL4nkcode didn't notice the warning message and assumed it doesn't support URIs.

[bL4nkcode]

Thanks for testing that. I wonder why it doesn't work on blockchain. I am sure I remembered correctly that it used to work even with blockchain's wallet.

Blockchain wallet app supports URIs and here is a screenshot from my mobile after clicking one of the links from OP:

If the blockchain wallet is empty, it won't open the send tab and fill up the fields. It will briefly display an error message stating that you don't have enough balance.
I suupose this is why bL4nkcode thought it doesn't support URIs.

btw, you can add bitpay to the list.

What actually happens is after I click the URI link actually blockchain.com app shows in the list just like the screenshot but after selecting blockchain.com app, nothing happens, it just open the app, though I don't have a balance but there's nothing message shows that I don't have enough balance or what, unlike on mycelium, electrum, and trustwallet even there's no balance on the wallet it still go to the sending page with the details provided on the URI.
But maybe I'm using a bit outdated blockchain app that's why.

[khaled0111]

...

Weird! I just realized that the warning message appears only when I click on the second link! Maybe it has something to do with the comment part at the end of the link!

Since the app appears on the open with list, it means it supports that URI scheme. Try clicking the second link, blockchain will open the main page but you will see a small warning text in red at the bottom (it disappears quickly).

edit: here is how it looks like:

[Pmalek]

Weird! I just realized that the warning message appears only when I click on the second link! Maybe it has something to do with the comment part at the end of the link!

The difference between the first and second link is in the amounts and the added comment. The first one has a "Payment to Pmalek" comment while the second one has no comment at all. The obvious question to ask now is, does the blockchain wallet have a comments field while sending crypto? If it doesn't, maybe that's why the first links isn't recognized by the app.   

[ABCbits]

Weird! I just realized that the warning message appears only when I click on the second link! Maybe it has something to do with the comment part at the end of the link!

The difference between the first and second link is in the amounts and the added comment. The first one has a "Payment to Pmalek" comment while the second one has no comment at all. The obvious question to ask now is, does the blockchain wallet have a comments field while sending crypto? If it doesn't, maybe that's why the first links isn't recognized by the app.   

Even if the wallet doesn't support adding message/note to a transaction, the wallet could simply ignore the message on URI. It basically means Blockchain wallet made a bug when implementing BIP 21.

[FatFork]

The obvious question to ask now is, does the blockchain wallet have a comments field while sending crypto? If it doesn't, maybe that's why the first links isn't recognized by the app.  

Yes, it does. And, the URI scheme works with the Blockcain.com wallet so you can put it back on the list.

BlueWallet also works (obviously, mainnet wallet only, not LN), so you can add it as well.