SparkAudit: autonomous smart-contract security auditing on a private NVIDIA DGX Spark. Send Solidity source or a verified contract address; get severity-ranked findings (reentrancy, access-control, unchecked calls, tx.origin, weak RNG...) with exploit + fix. Free diagnosis tier, no signup. Deep audit (gpt-oss:120b) auto-payable via standard x402 on Base, 0.25 USDC. Also reachable by email johnwork@agentmail.to. Landing: https://ends-missing-feedback-puzzles.trycloudflare.com