nftdata-mcp

nftdata-mcp

An MCP server that exposes the NFT Data API to AI clients (Claude Desktop, Cursor, etc.) as a single tool. It handles the x402 payment flow automatically.

• npm: https://www.npmjs.com/package/nftdata-mcp
• MCP Registry: https://registry.modelcontextprotocol.io/?q=nftdata

Tool

get_collection_data

Returns OpenSea collection market data in one call.

Parameter	Type	Description
collection	string	OpenSea collection slug, from opensea.io/collection/<slug> (e.g. azuki)

Returned fields: name, slug, contracts, floor_price, floor_price_currency, one_day_sales, one_day_volume, seven_day_sales, seven_day_volume, thirty_day_sales, thirty_day_volume, total_sales, total_volume, num_owners, total_supply, created_date. Volume and price currencies are given in the matching *_currency fields (ETH, USDC, HYPE, ...).

Each call costs $0.002 (USDC on Base, paid via x402).

Requirements

• Node.js 20+
• A wallet private key funded with a small amount of USDC on Base

Use a dedicated wallet with only a small balance. Never use your main wallet.

Quick start (npx)

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "nftdata": {
      "command": "npx",
      "args": ["-y", "nftdata-mcp"],
      "env": {
        "EVM_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Restart Claude Desktop, then ask for example: "What is the floor price and 7-day volume of azuki?"

Run from source

npm install

Set the key for the current shell session only, then start:

# macOS / Linux
export EVM_PRIVATE_KEY=0x...
npm start

# Windows PowerShell
$env:EVM_PRIVATE_KEY = "0x..."
npm start

:: Windows cmd
set EVM_PRIVATE_KEY=0x...
npm start

The server waits for an MCP client on stdin, so running it by hand just shows no output; it is meant to be launched by an MCP client.

To use a local checkout with Claude Desktop, point args to ["tsx", "/absolute/path/to/nftdata-mcp/server.ts"] with "command": "npx".

Build

npm run build   # compiles server.ts and lib.ts to dist/
npm test        # offline unit tests, no network and no payments

Configuration

Variable	Required	Default	Description
EVM_PRIVATE_KEY	yes	–	Private key (0x + 64 hex chars) of the wallet that pays for calls
NFTDATA_MAX_REQUESTS	no	100	Max signed payments per session. Integer 1–1000; any other value stops startup with an error
NFTDATA_TIMEOUT_MS	no	15000	Request timeout in milliseconds (1000–60000)
NFTDATA_URL	no	https://www.nftdata.app/api/get-collection-data	Accepts only the official NFT Data endpoint (www.nftdata.app or nftdata.app); anything else stops startup

Behavior

• Sends POST /api/get-collection-data with body {"collection": "<slug>"}.
• The slug is trimmed and lowercased, then must match ^[a-z0-9][a-z0-9_-]*$ (max 100 characters); otherwise no request is made.
• Only Base mainnet (eip155:8453) is registered with the x402 client. Before signing, every payment challenge is checked: scheme exact, network Base mainnet, token USDC on Base, amount exactly 2000 atomic units ($0.002), and recipient (must be 0x344143199642e87320785823c20c2df107d17534). Anything else is refused without signing.
• Each signed payment counts against NFTDATA_MAX_REQUESTS, including payments for requests that later fail or time out.
• No automatic retries: one tool call makes at most one payment attempt.
• Caches successful responses for 5 minutes per slug. Concurrent identical calls share a single in-flight request.
• Returns generic errors for 400 (invalid slug), 404 (collection not found), 429 (rate limit, with Retry-After), timeouts and other failures; server and payment details are not passed to the MCP client.

Limitations

• Only x402 on Base is supported. Solana and MPP payment methods are not implemented in this wrapper.
• The expected recipient address is hardcoded in lib.ts. If the NFT Data payout address ever changes, update OFFICIAL_PAY_TO and release a new version.
• The payment hook (server.ts) depends on the installed @x402/* SDK and is not covered by the offline tests.
• The x402 client libraries change quickly; if imports fail, check the current x402 docs.

API reference

• OpenAPI: https://www.nftdata.app/openapi.json
• Docs: https://www.nftdata.app/docs