{
  "tool_id": "art-608-erc2981-royalty-calculator",
  "kernel_id": "art-608-erc2981-royalty-calculator",
  "display_name": "ERC-2981 Royalty Calculator",
  "tool_version": "1.0.0",
  "mandate_type": "payment_policy",
  "purpose": "Recomputes an ERC-2981 royalty amount as floor(sale_price * royalty_fraction_bps / 10000) -- the same integer-division convention the OpenZeppelin reference ERC2981 implementation uses -- from a caller-declared sale_price and royalty_fraction_bps, using BigInt arithmetic throughout so a sale_price beyond Number.MAX_SAFE_INTEGER never loses precision. Flags a bps value above 10000 (100%) as out of range (the value the reference implementation reverts on) while still reporting the raw recompute, and compares against an optional claimed_royalty_amount. Zero network calls: this tool never queries a contract's actual royaltyInfo() return value -- sale_price, royalty_fraction_bps, and receiver are all caller-declared. Cross-links 528-nft-metadata-validator and 521-cant-be-evil-nft-license-picker for adjacent NFT-standard surfaces (metadata shape, license terms) this tool does not cover. ERC-2981 royalty payment is a voluntary off-chain convention: this tool makes no claim that any marketplace will actually pay the computed amount.",
  "control_description": "Recomputes an ERC-2981 royalty amount as floor(sale_price * royalty_fraction_bps / 10000) -- the same integer-division convention the OpenZeppelin reference ERC2981 implementation uses -- from a caller-declared sale_price and royalty_fraction_bps, using BigInt arithmetic throughout so a sale_price beyond Number.MAX_SAFE_INTEGER never loses precision. Flags a bps value above 10000 (100%) as out of range (the value the reference implementation reverts on) while still reporting the raw recompute, and compares against an optional claimed_royalty_amount. Zero network calls: this tool never queries a contract's actual royaltyInfo() return value -- sale_price, royalty_fraction_bps, and receiver are all caller-declared. Cross-links 528-nft-metadata-validator and 521-cant-be-evil-nft-license-picker for adjacent NFT-standard surfaces (metadata shape, license terms) this tool does not cover. ERC-2981 royalty payment is a voluntary off-chain convention: this tool makes no claim that any marketplace will actually pay the computed amount.",
  "declared_inputs": [],
  "declared_outputs": [],
  "kernel_digest": "sha256:c573de67d9322a020f559748f9321e33213cedf75800b73729610cbe6cec2a94",
  "trust_label": "independently verified: zkVM execution proof (risc0/groth16-bn254)",
  "data_vintage": "2026-08-12",
  "last_validated": "2026-08-12",
  "conformance_fixtures_vendored": true,
  "compute_proof_ready": "ready",
  "wave": 99,
  "source_url": "https://ainumbers.co/chaingraph/art-608-erc2981-royalty-calculator.html",
  "generated_at": "2026-08-15T11:12:17.704Z"
}