ENS MCP Server

MCP Server for Ethereum Name Service (ENS), enabling Claude to interact with the ENS system to resolve names, check availability, retrieve records, and more.

npm package: https://www.npmjs.com/package/mcp-server-ens

Tools

resolve-name

Resolve an ENS name to an Ethereum address

Required inputs:
- name (string): The ENS name to resolve (e.g., 'vitalik.eth')
Returns: The corresponding Ethereum address or an error message

reverse-lookup

Get the ENS name for an Ethereum address

Required inputs:
- address (string): The Ethereum address to look up
Returns: The corresponding ENS name or an indication that no name was found

get-text-record

Get a text record for an ENS name

Required inputs:
- name (string): The ENS name to query
- key (string): The record key to look up (e.g., 'email', 'url', 'avatar', 'description', 'twitter', etc.)
Returns: The value of the specified text record or indication that no record was found

check-availability

Check if an ENS name is available for registration

Required inputs:
- name (string): The ENS name to check
Returns: Availability status and owner information if registered

get-all-records

Get all available information for an ENS name

Required inputs:
- name (string): The ENS name to query
Returns: Comprehensive information including resolver address, text records, addresses, content hash, ownership, and expiration details

get-subdomains

Get subdomains for an ENS name

Required inputs:
- name (string): The ENS name to query for subdomains
Returns: List of subdomains with their owner information

get-name-history

Get the history of an ENS name

Required inputs:
- name (string): The ENS name to check history for
Returns: Historical events related to the name, including transfers, resolver changes, and registration events

get-registration-price

Get the price to register an ENS name

Required inputs:
- name (string): The ENS name to check price for
Optional inputs:
- duration (number, default: 1): Registration duration in years
Returns: Registration price breakdown including base price, premium, and total

Setup

Prerequisites

Node.js (v16 or higher)
npm or yarn
Access to Ethereum RPC providers (public or private)

Installation

Clone the repository or create a new project:

git clone https://github.com/JustaName-id/ens-mcp-server

Install dependencies:

npm i

Configure Ethereum providers: Create a .env file in the project root with the following (optional):

PROVIDER_URL=https://your-provider-url.com,https://your-backup-provider.com

If no providers are specified, the server will use these defaults:

Usage with Claude Desktop

Add the following to your claude_desktop_config.json:

Using npx

{
  "mcpServers": {
    "ens": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-server-ens"
      ],
      "env": {
        "PROVIDER_URL": "https://your-provider-url.com,https://your-backup-provider.com"
      }
    }
  }
}

Using local script

{
  "mcpServers": {
    "ens": {
      "command": "node",
      "args": [
        "/path/to/your/server.js"
      ],
      "env": {
        "PROVIDER_URL": "https://your-provider-url.com,https://your-backup-provider.com"
      }
    }
  }
}

Usage with Claude Code

claude mcp add ens -- npx -y mcp-server-ens

With custom providers:

claude mcp add ens -e PROVIDER_URL="https://your-provider-url.com" -- npx -y mcp-server-ens

Verify it's connected:

claude mcp list

Error Handling

The server implements robust error handling for various scenarios:

Network errors connecting to Ethereum providers
Invalid ENS names or Ethereum addresses
ENS-specific errors
General operational errors

All errors are normalized into user-friendly messages while preserving technical details for debugging.

Publishing

To publish as an npm package:

npm publish --access public

Troubleshooting

If you encounter errors:

Verify your Ethereum providers are working and accessible
Check that the ENS names you're querying are formatted correctly
Ensure you have the latest version of the ENS libraries
Try using multiple providers by comma-separating them in the PROVIDER_URL environment variable

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.