Skip to content

3rd-Party MCP Servers

NEX natively supports mounting custom Model Context Protocol (MCP) servers. This allows you to seamlessly integrate external tools, databases, and proprietary EDA services directly into NEX's reasoning loop—without having to rely on ad-hoc shell scripts.

What is MCP?

MCP is a standard that allows AI assistants to securely access external data sources and capabilities. By connecting an MCP server, NEX can discover new tools and call them exactly as if they were built-in application tools.

Mounting and Using Servers

NEX dynamically manages custom MCP servers, meaning it can mount specific servers based on your requests and unmount them later to save context space.

When an MCP server is mounted, NEX will:

  1. Discover the tools exposed by the server.
  2. Read their descriptions and parameter schemas.
  3. Automatically invoke them when your task requires those specific capabilities.

Example: Mounting an SQLite MCP Server

To see MCP in action, you can easily mount a local SQLite server. This allows NEX to discover database tools, execute SQL queries, and manipulate data directly.

Prerequisites

This example uses uvx to automatically download and run the Python-based SQLite MCP server. To replicate this exactly, ensure you have the uv package manager installed on your system.

  1. Create the Database and Config File: In your working directory, create a blank database and an mcp.json configuration file.
Terminal
touch test.db
mcp.json
{
  "mcpServers": {
    "sqlite": {
      "command": "uvx",
      "args": [
        "--with",
        "mcp<1.2.0",
        "mcp-server-sqlite",
        "--db-path",
        "./test.db"
      ]
    }
  }
}
  1. Interact via NEX: Launch NEX and instruct it to mount the server and use the new database capabilities:
Prompt
Mount the sqlite MCP server. Then, create a 'components' table with id, name, and footprint columns, insert a few common resistors, and read the table back.
  1. Observe the Tool Usage: NEX will read your configuration, mount the sqlite server, dynamically discover its SQL execution tools, and complete your request without requiring any custom shell scripts.

Best Practices

  • Prefer MCP over Shell Scripts: Whenever a capability is exposed through an integrated MCP server, NEX is instructed to use that structured interface. This provides much more reliable execution compared to invoking underlying executables manually through the shell.
  • Dynamic Remounting: If a previously used custom tool becomes unavailable (e.g., if it was unmounted to save context), NEX will automatically attempt to remount the required MCP server when you ask it to perform the task again.