01MerchantOffer. A request without payment gets 402 and a fresh invoice the merchant signed, offered over x402 and MPP.
1 ms
02SolverQuote. The solver checks the invoice and its liquidity, then signs a quote: amount plus fee.
5 ms
03AgentSign. The agent signs its channel's next total, with a payment id that makes retries safe.
15 ms
04Solver → merchantForward. The solver raises its own channel to the merchant, and the merchant signs a receipt.
15 ms
05Agent → merchantFetch. The agent repeats the request with the receipt. The merchant serves it once.
17 ms
Payment 016● settled off chain
Protocolx402 v2
RequestPOST /api/echo
Amount2,000 zat
Solver fee100 zat
Protocol time17 ms
Chain txnone
Receiptsigned by merchant ✓
Oct 27, 2026, merchant-d in proxy mode, co-located with agent and solver. Steps 03 and 04 finish together: the agent's signature and the solver's forward are one exchange.