Probe
Call the resource with no payment and expect a structured HTTP 402 requirement.
Interactive pattern
Try a paid endpoint agents can actually buy.
Use this page as a buyer-agent script: ask for the resource, get a 402, approve signing in your wallet, retry with proof, and save the receipt.
What should happen
The flow is visible at every step.
Nothing should feel like a dead end. If a wallet, rail, provider, or endpoint blocks, the agent should say what happened and what the next useful move is.
Approve
Show amount, asset, network, payee, expiry, and exact resource before asking for wallet signing.
Retry
Send proof, invoke once, stream progress if slow, and return the receipt.
Agent prompt
Use Wisely. Call /paid/facilitator-echo with no payment, read the 402 requirement, ask me before signing, retry after payment, and save the receipt.