evm-mcp

An MCP (Model Context Protocol) server that exposes EVM blockchain tools to AI assistants. Built with viem and the MCP SDK, it lets any MCP-compatible client (Claude Desktop, etc.) read balances and send ETH on local EVM chains.

Tools

Tool	Description	Parameters
get-eth-balance	Fetch the ETH balance of any address	address — the wallet address
send-eth	Send ETH from the configured wallet to another address	toAddress, amount (in ETH)

Supported Chains

Currently supports local development chains via viem:

• anvil (chain ID 31337)
• localhost (chain ID 1337)

The active chain is selected at startup via the CHAIN_ID environment variable.

Prerequisites

• Node.js 18+
• A running local EVM node (e.g. Anvil from Foundry)

Setup

1. Install dependencies

npm install

2. Build

npm run build

3. Set environment variables

export CHAIN_ID=31337        # Chain ID of your local node
export PRIVATE_KEY=0x...     # Private key of the signing wallet

Usage

Run the server directly:

node build/index.js

The server communicates over stdio using the MCP protocol.

Claude Desktop integration

Add the following to your claude_desktop_config.json:

{
  "mcpServers": {
    "evm": {
      "command": "node",
      "args": ["/path/to/evm-mcp/build/index.js"],
      "env": {
        "CHAIN_ID": "31337",
        "PRIVATE_KEY": "0x<your-private-key>"
      }
    }
  }
}

Development

# Compile TypeScript in watch mode
npx tsc --watch

Dependencies

Package	Purpose
@modelcontextprotocol/sdk	MCP server framework
viem	EVM client (balance queries, transaction sending)
zod	Tool parameter validation