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"
    }
  }
}

Related MCP server: nft-floor

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

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

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