{"protocol":"ACP","version":"1.0","provider":"xproof","chain":"MultiversX","products":[{"id":"xproof-certification","name":"xproof Certification","description":"xproof is the canonical proof layer for AI agents. Create cryptographic proof of existence and integrity for digital files on MultiversX blockchain. Records SHA-256 hash with timestamp, providing immutable evidence of file ownership at a specific point in time.","pricing":{"type":"fixed","amount":"0.01","currency":"USD","note":"Price converted to EGLD at checkout based on current exchange rate"},"inputs":{"file_hash":"SHA-256 hash of the file (64 character hex string)","filename":"Original filename with extension","author_name":"Optional - Name of the author/certifier","metadata":"Optional - Additional JSON metadata (supports model_hash, strategy_hash, version_number and any custom fields). Searchable via GET /api/proofs/search"},"outputs":{"certification_id":"Unique certification ID","certificate_url":"URL to download PDF certificate","proof_url":"Public verification page URL","tx_hash":"MultiversX transaction hash","blockchain_explorer_url":"Link to view transaction on explorer"},"checkout_requirements":{"payer_wallet":"Required (non-admin). The MultiversX wallet address (erd1...) that will send the EGLD payment.","payer_wallet_signature":"Required (non-admin). Hex-encoded Ed25519 signature proving you control payer_wallet. Must be 64 bytes (128 hex chars).","message_format":"xproof-acp-checkout:<product_id>:<file_hash>:<payer_wallet>","message_format_example":"xproof-acp-checkout:xproof-certification:<sha256_file_hash>:<erd1...>","signing_algorithm":"Ed25519 raw signature (no MultiversX prefix) over UTF-8 message bytes using the private key corresponding to payer_wallet's public key. Sign then hex-encode the 64-byte signature."}}]}