BIP 73 Payment URL Negotiation made simple. See what the proposal changes, its current status and what it means for Bitcoin users and operators.
BIP 73 Payment URL Negotiation: This guide explains BIP 73 Use "Accept" header for response type negotiation with Payment Request URLs in plain English. It covers the problem behind the BIP, why it matters and whether the proposal is part of Bitcoin today.
BIP 73 Payment URL Negotiation: Embedding a destination, amount and long payment-request URL inside one bitcoin URI produced dense QR symbols that cameras struggled to scan.
A node operator is checking BIP 73 Payment URL Negotiation. If both were offered, the payment request took precedence under the simplified rules. With neither or no Accept header, the server could return HTML useful to a general QR scanner or web browser.
Embedding a destination, amount and long payment-request URL inside one bitcoin URI produced dense QR symbols that cameras struggled to scan. BIP 73 let the QR contain only an endpoint. The wallet then requested the representation it understood, trading visual density for an online lookup and its associated availability and substitution risks.
A client advertised application/bitcoin-paymentrequest for BIP 70 or text/uri-list for a bitcoin URI. If both were offered, the payment request took precedence under the simplified rules. With neither or no Accept header, the server could return HTML useful to a general QR scanner or web browser.
For text/uri-list, the wallet used only the first returned item and expected it to be a bitcoin URI. It still needed to parse the address, network, amount and parameters safely and require approval. Extra lines were ignored rather than treated as alternative destinations or fallback commands.
A generic scanner could open the endpoint as a webpage containing a bitcoin link, letting the user continue into an installed wallet. HTML is active untrusted web content, not a payment protocol response. Wallet code should not render it in a privileged signing context or follow scripts and redirects without normal browser safeguards.
The endpoint controls the response and can observe request metadata. HTTPS authenticates the web endpoint under its certificate but does not independently verify the commercial intent. Redirects can cross origins, and content negotiation can be cached incorrectly unless responses vary by Accept. Clients need tight redirect, MIME and size rules.
Only wallets implementing BIP 73 understood a bare payment endpoint from a QR code. Others required an alternate bitcoin URI or generic scanner flow. Current support for BIP 70 and its media type is limited, so merchants should publish an explicit modern fallback and never assume historical deployed status means broad present-day compatibility.
Developers test the proposal with made-up data on an isolated test network. They check normal cases and deliberately invalid cases. Different implementations should reach the same result before anyone relies on the proposal.
BIP 73 Payment URL Negotiation: Embedding a destination, amount and long payment-request URL inside one bitcoin URI produced dense QR symbols that cameras struggled to scan.
Embedding a destination, amount and long payment-request URL inside one bitcoin URI produced dense QR symbols that cameras struggled to scan.
A client advertised application/bitcoin-paymentrequest for BIP 70 or text/uri-list for a bitcoin URI.
For text/uri-list, the wallet used only the first returned item and expected it to be a bitcoin URI.
BIP 73 reduced QR density through ordinary HTTP negotiation, but it moved trust and availability into a web endpoint. Safe compatibility requires strict media handling, visible fallback and a complete confirmation step after every scanned response.
Check the current specification status and the documentation for the exact implementation you operate before moving production funds or changing a mining node.
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