Single-payee x402 + on-chain split

A match payment is one transfer. The 402 challenge lists a single accept:

Gross — the full price in USDC to the split address (a 0xSplits PushSplit v2 on Base).

This is spec-compliant single-payee x402: the buyer signs one payment. The seller cut and the protocol fee are settled on-chain, not as separate payment legs.

Rail

USDC on Base (eip155:8453) via x402.

Buyers (or their wallets / facilitators / clients) satisfy the one challenge; the hub marks the match paid and issues a grant.

How the split works

Buyer pays gross USDC once to the split address (payTo).
The gross accumulates in the 0xSplits split contract.
A keeper calls the split's distribute() — an immutable, on-chain fan-out to the recipients: seller (e.g. 95%) + hub protocol fee (e.g. 5%).

Why single-payee: standard x402 clients sign one payment; the split is enforced on-chain by an immutable contract, so the hub never custodies the seller's cut and never proxies token streams. The extra.breakdown on the accept is display-only — the on-chain allocation is authoritative.