NFT

What it proves

• On-chain ownership of a specific NFT by a wallet at current or specified block.

When to use

• Gate features or access by NFT holdings.

• Provide collector credentials for allowlists and airdrops.

Inputs

• See authoritative JSON Schema: ../schemas/nft-ownership.json

• Typical fields:

  • ownerAddress: string (address) — holder wallet (SDK may set)

  • contractAddress: string (address) — NFT contract

  • tokenId: string — token ID

  • chainId: number — EVM chain ID

  • blockNumber?: number — optional historical check

Outputs

• qHash-based proof with verification data (owner, contract, tokenId, chainId). Cross-chain voucher propagation can be enabled.

Output shape (representative)

{
  "success": true,
  "data": {
    "qHash": "0x...",
    "status": "verified",
    "verifiedVerifiers": [
      {
        "verifierId": "nft-ownership",
        "verified": true,
        "status": "nft_ownership_verified",
        "data": {
          "input": {
            "ownerAddress": "0x...",
            "contractAddress": "0x...",
            "tokenId": "1234",
            "chainId": 1,
            "tokenType": "erc721"
          },
          "onChainData": {
            "actualOwner": "0x..."
          },
          "verificationTimestamp": 1730000000000
        }
      }
    ]
  }
}

Privacy

• No PII. Uses public chain data. Proof visibility follows your privacyLevel.

Options

• privacyLevel, publicDisplay, enableIpfs, targetChains (testnets only)

High‑value use cases

• Token‑gated commerce and loyalty tiers

• Collector credentials for ticketing or airdrops

• Rights gating for derivative content and remix permissions

SDK example

const result = await client.verify({
  verifier: 'nft-ownership',
  data: {
    ownerAddress: walletAddress,
    contractAddress: '0x...NFT',
    tokenId: '1234',
    chainId: 1
  }
});

HTTP API (manual) outline Use /verification/standardize → sign → submit to /verification. See API reference.

Common errors

• INVALID_WALLET_ADDRESS, SIGNATURE_INVALID

• VERIFIER_NOT_FOUND

• Token not owned / token not found (verifier-specific status)

API reference

• Endpoints and response shapes: ../../api/README.md See also

• Privacy & options: ../../PRIVACY.md

• Protocol standards: ../../STANDARDS.md