Interesting approach. We run 124 x402 endpoints at httpay.xyz and the "verify work was done" problem is real — especially for compute-heavy tasks like image generation or LLM inference where the response time varies.

Currently we handle this by only settling after the response is delivered, but that puts trust on the server side. A third-party verification layer could work for higher-value transactions.

What's the latency overhead of the verification step? For micropayments ($0.001-$0.01 per call), adding even 500ms of verification latency might not be worth it. But for higher-value agent tasks ($1+), escrow + verify makes a lot of sense.