One paid call on allooloo.io for $0.01 USDC: the surface's own statement of record (a market node: its list_nodes line; a product: its record of record; allooloo.io: the estate scale block), public-record only, with an EdDSA-signed receipt that resolves forever at https://allooloo.io/x402/receipt/{nonce}. Doctrine: https://agentic-x402.ai/.