NFT Metadata API

NFT metadata lookup -- name, image, attributes, collection info from contract + token ID. Ethereum and Base. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "nft-metadata": {
      "url": "https://nft-metadata.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://nft-metadata.api.klymax402.com/api/metadata" \
  -H "Content-Type: application/json" \
  -d '{"contract":"...","tokenId":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

Tool	Method	Path	Price	Description
crypto_get_nft_metadata	POST	/api/metadata	$0.008	Fetch NFT metadata from contract and token ID

crypto_get_nft_metadata

Use this when you need to fetch metadata for a specific NFT by contract address and token ID. Returns full NFT details in JSON.

Parameters

Name	Type	Required	Description
contract	string	yes	NFT contract address (e.g. 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D)
tokenId	string	yes	Token ID within the contract
chain	string	no	Blockchain: 'ethereum' or 'base' (default: ethereum)

Returns

• name -- NFT token name
• description -- token description text
• imageUrl -- URL to the NFT image/media
• attributes -- array of trait objects with trait_type and value
• collection -- collection name and contract info
• tokenStandard -- ERC-721 or ERC-1155
• chain -- which blockchain the NFT is on

Example response:

{"name":"Bored Ape #1234","description":"A unique digital collectible...","imageUrl":"ipfs://Qm...","attributes":[{"trait_type":"Background","value":"Blue"},{"trait_type":"Fur","value":"Gold"}],"collection":"BoredApeYachtClub","tokenStandard":"ERC-721","chain":"ethereum"}

When to use: NFT verification, display, and trait analysis. Essential for NFT marketplace agents and collection tools.

Not for: wallet balances (use wallet_get_portfolio), ENS resolution (use crypto_resolve_ens), token safety (use token_check_safety).

Example agent prompts

• "Fetch metadata for a specific NFT by contract address and token ID"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
• Network: Base L2 (eip155:8453)
• Asset: USDC
• Facilitator: Coinbase CDP (primary), PayAI (fallback)
• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt
• Full API reference: https://klymax402.com/llms-full.txt
• Live stats: https://klymax402.com/stats

License

MIT