Proof of Prior Delivery
In peer-to-peer compute markets, proving service delivery is the hard problem. Not routing, not pricing, not discovery — proving that a seller actually delivered what they were paid for, without a trusted intermediary watching the exchange.
Most decentralized compute projects sidestep this. They use self-reported metrics (trivially gameable), trusted validators (re-introducing centralization), or optimistic assumptions with dispute windows (which require honest majorities). These are reasonable tradeoffs, but they're not proofs. They're social mechanisms dressed up as cryptographic ones.
AntSeed's answer is the metadataHash — a hash of delivery metrics that the buyer signs into every payment authorization. When the seller wants to settle more funds, they must submit a signature that includes this hash. The hash covers what was actually delivered: tokens in, tokens out, average latency, number of requests. The seller can't get paid without presenting proof of what the buyer received. That proof is the metadataHash.