{"service":"Witness","version":"0.1.0-phase-c-passed","phase":"C-testnet-passed","mcp":"/mcp","paid_http":"/v1/contract-witness","tool":"contract_witness","payment":{"protocol":"x402-v2","network":"eip155:84532","facilitator":"https://api.cdp.coinbase.com/platform/v2/x402","price":"$0.001","testnet_only":true},"proof_semantics":{"input_backward":"OLD-valid -> NEW-invalid","output_backward":"NEW-valid -> OLD-invalid","unknown_means_compatible":false}}