Proofwork Base USDC Receipt Verification (AgenticTrade)

Read-only Base-mainnet USDC payment verification. For a paid marketplace call, request POST or GET /v1/base-usdc-receipt on the listed endpoint with a transaction hash, expected recipient, and exact amount. Returns receipt success, Circle USDC transfer evidence, confirmations, finality, and Basescan links. No keys, signing, broadcasting, custody, or trading.