Bitcoin Forum

I'd like to propose a BIP for a standard URI scheme to allow wallet
operators that implement instant exchange or pegging to other currencies,
cryptocurrencies or asset classes to allow for interoperable communications
of rates and other pertinent information.

The idea is to include in the wallet address as parameters information that
supplements the presentation of a proposed transaction.

For example, a wallet operator that instantly exchanges bitcoin to gold
would present a wallet address as follows:
bitcoin:1JohnxNT6jRzhu3H1wgVFbSGKmHP4EUjUV?currency=xau&rate=0.2084&expires=1458432000 (bitcoin:1JohnxNT6jRzhu3H1wgVFbSGKmHP4EUjUV?currency=xau&rate=0.2084&expires=1458432000)

Wherein:
<currency> :  the currency, cryptocurrency or asset that the transaction
will end up as encoded in ISO 4217 if applicable.
<rate> : the bitcoin to <currency> rate as dictated by receiving wallet
<expires> : unix timestamp of when the rate loses validity

This would allow the sending wallet the ability to present up-to-date
exchange rates. When, for example, a wallet operator that pegs to the USD
scans the address above, it would be able to present to the user the
following information:

1. USD to XAU rate
2. How much XAU will be received by the address
3. How long before the rates expires

Thoughts?


BTW, I've posted this to the bitcoin-dev mailing list (https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-September/011008.html).

Hello community, I had some time to work on this idea some more and would like to present it for everyone's comment:

Title: Extension to URI Scheme (BIP21) enabling currency exchange presentation
Author: John Bailon <john@sci.ph>
Status: Proposed
Type: Standards Track
Created: 2016-06-30

This BIP is a modification of an earlier BIP 0021 (https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki) by Nils Schneider and Matt Corallo. BIP 0021 was based off an earlier document by Luke Dashjr. Exchange rates, its validity, and destination currency are added.

Abstract
This BIP proposes additional query keys to the URI scheme for making Bitcoin payments that are automatically converted to a different currency by address owner.

Motivation
The purpose of these additional query keys is to enable users to easily view destination currency and exchange rate at which their Bitcoin payment will be converted to by address owner. The rates are also time-bound by an expiration timestamp.

Added Exchange Rate Related Query Keys
*exchange-currency: Currency at which the address owner/payment recipient will convert the payment to, following ISO 4217 (https://en.wikipedia.org/wiki/ISO_4217) standard, if available.
*exchange-rate: The rate at which bitcoins sent will be converted to the destination currency represented in decimal number format. This number shall be multiplied to whatever amount is sent.
*exchange-expiry: Unix timestamp of when the exchange rate expires.

Note: It is optional to use these three new keys altogether, however when one is used, the two other keys are required.

Presentation and Control
Bitcoin clients should make sure that when the user has hit send, a reasonable amount of time is left before the exchange_rate_expiry has elapsed.
Bitcoin clients presenting a Bitcoin address with the 3 exchange- keys should monitor the expiry timestamp and present to the user a notice when the expiration timestamp has elapsed. The user may be asked or can be automatically presented a refreshed rate.

Accessibility (URI scheme name)
Similar to BIP 0021, should someone from the outside happen to see such a URI, the URI scheme name already gives a description.


Simple syntax
Request 1 BTC to be converted to USD at a rate of 642.25, valid until 12:00 AM, July 1, 2016 UTC:

Request to receive any amount to be converted to ETH at a rate of 51.786639047, valid until 12:00 AM, July 1, 2016 UTC:

Note: Characters must be URI encoded properly.

Bitcoin does not know its exchange rate against USD/JPY/CNY/XAU. Any currency conversion scheme at protocol level is pretty meaningless.

Yes, of course but the person/entity who generates the URI does. Or more accurately, they would be the one to set the rate.

This proposal doesn't care about how valid or accurate an exchange rate is. It's only meant to standardize the way in which users are presented with what a bitcoin transaction is meant for.

Oh you are so confused.  Just take it from me, your idea is totally dead. 

Please elaborate?