Arbgent

An MCP server that lets Claude bridge and send ETH across Ethereum and Arbitrum. It exposes three tools:

• bridge_eth_L1_to_L2 — deposit ETH from a parent (L1) chain to a child (L2) chain
• bridge_status — check the status of a bridge deposit
• send_eth — send ETH to an address on a given chain

Supported chains: Ethereum Mainnet (1), Ethereum Sepolia (11155111), Arbitrum One (42161), Arbitrum Sepolia (421614).

Setup

All you need is a private key and to register the server in your Claude config.

1. Install and build

pnpm install
pnpm build

This compiles the server to dist/index.js.

2. Provide your private key

The server reads the signing key from the PRIVATE_KEY environment variable, which you pass through the Claude config (see the next step).

⚠️ This key signs and sends real transactions. Use a dedicated, low-value wallet — never your main account.

Optional: custom RPC URLs

Public RPCs are used by default. To override any of them, add these alongside PRIVATE_KEY in the Claude config:

ARB_ONE_RPC=...
ETH_MAINNET_RPC=...
ARB_SEPOLIA_RPC=...
ETH_SEPOLIA_RPC=...

3. Register Arbgent in the Claude files

Add the server to your Claude MCP config so Claude can launch it.

Claude Code — add an .mcp.json in your project (or your user config):

{
  "mcpServers": {
    "Arbgent": {
      "command": "node",
      "args": ["/absolute/path/to/Arbgent/dist/index.js"],
      "env": {
        "PRIVATE_KEY": "0xyour_private_key_here"
      }
    }
  }
}

Claude Desktop — add the same block to claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Use the absolute path to dist/index.js, and put your private key in the env block as shown.

4. Restart Claude

Restart Claude Code / Claude Desktop so it picks up the config. You should see Arbgent connect (it logs Arbgent is Running), and the three tools become available.

Usage

Once connected, just ask Claude in natural language, e.g.:

• "Bridge 0.01 ETH from Sepolia to Arbitrum Sepolia."
• "What's the status of bridge tx 0x… from chain 11155111 to 421614?"
• "Send 0.005 ETH to 0x… on Arbitrum One."