@igoforth/crypto-mcp

Minimal, auditable MCP server for inspecting Ethereum/Polygon wallet balances and transactions.

Security

• Minimal dependencies: Only viem, @modelcontextprotocol/sdk, and zod
• Read-only: No transaction signing or wallet operations
• Auditable: Single file, <300 lines of code
• Type-safe: Full TypeScript with Zod validation

Tools

| Tool | Description | |------|-------------| | get_balance | Get wallet balance — native only, specific ERC-20, or "all" for native + common tokens | | get_transaction_count | Get transaction count (nonce) for an address | | get_erc20_transfers | Get ERC-20 transfer history (incoming/outgoing) |

Supported Chains

• Ethereum Mainnet
• Polygon (default)
• Polygon Amoy Testnet

Common Tokens (Polygon)

| Token | Address | |-------|---------| | USDC.e | 0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174 | | USDC | 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 | | USDT | 0xc2132D05D31c914a87C6611C10748AEb04B58e8F | | DAI | 0x8f3Cf7ad23Cd3CaDbD9735AFf958023239c6A063 | | WETH | 0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619 | | WMATIC | 0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270 |

Installation

npm install -g @igoforth/crypto-mcp

Or with pnpm:

pnpm add -g @igoforth/crypto-mcp

Usage

Claude Code

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "crypto-wallet": {
      "command": "crypto-mcp"
    }
  }
}

Claude Desktop

Add to your Claude Desktop config:

{
  "mcpServers": {
    "crypto-wallet": {
      "command": "npx",
      "args": ["-y", "@igoforth/crypto-mcp"]
    }
  }
}

Example Queries

Once configured, you can ask:

• "Check my USDC balance on Polygon for address 0x..."
• "Get all token balances for 0x..."
• "What's the MATIC balance for my wallet?"
• "Show recent USDC transfers for 0x..."

RPC Configuration

Uses PublicNode free RPC endpoints by default — no API keys required.

All tools accept an optional rpcUrl parameter to use a custom RPC endpoint (e.g. Alchemy, Infura).

License

MIT