x402 Discovery, Identity, and Extensions
A payment protocol becomes much more interesting when software can also discover services.
15.1 Bazaar discovery
x402 includes a discovery mechanism often referred to as Bazaar.
The idea:
Agent:
"I need a company-risk report."
↓
Discovery:
"Here are services that offer that."
↓
Agent compares:
- function
- price
- network
- scheme
- metadata
↓
Agent selects one
↓
Agent pays
↓
Agent consumes resultThat moves x402 beyond “a paywall.”
It creates the ingredients for a machine-native marketplace.
A traditional marketplace lists:
Product
Seller
Price
Reviews
CheckoutA machine marketplace can expose:
Capability
Input schema
Output schema
Price
Payment requirements
Reliability metrics
Network
Machine-readable endpointThis is strategically important.
15.2 Sign-In-With-X / wallet identity
A pure pay-per-call model can be inefficient when a buyer should obtain continuing access after payment.
Wallet-based identity can let the system recognize that the holder of a particular wallet has already paid or has a particular right.
Conceptually:
Pay once
↓
Prove control of wallet later
↓
Regain authorized accessThis creates options for:
paid sessions;
purchased content;
membership access;
repeat access;
differentiated pricing.
15.3 Payment identifiers
Payment identifiers help correlate a commercial operation with its payment.
That matters for:
idempotency;
reconciliation;
invoice-like references;
retries;
support;
internal ledger mapping.
15.4 Builder attribution
Extensions can attribute payments to a builder/application.
Commercially this creates potential for:
affiliate economics;
distribution attribution;
revenue sharing;
channel attribution;
ecosystem commissions.
15.5 Gas-sponsoring extensions
A major user-experience problem in blockchain systems is:
The buyer has the stablecoin but does not have the native gas token.
Gas-sponsoring mechanisms can hide more of that complexity from the buyer.
That is important if x402 is to behave like ordinary internet infrastructure rather than like a crypto-native workflow.
Related x402 Explainers
If You Are Building This Commercially
If discovered services are part of a larger fintech product that also needs conventional bank identity, settlement, or treasury, named accounts and multi-currency accounts may sit behind the machine-facing payment layer.
Key Takeaway
Discovery is strategically significant because it moves x402 from “pay this known endpoint” toward machine procurement: discover, compare, pay, and consume.
This page is part of x402 Protocol Explained, the full guide to how machine-to-machine payments work.