MCP Setup Guide

Understanding the Model Context Protocol and how Nexus uses it.

What is MCP?

The Model Context Protocol (MCP) is a standard for AI assistants to access external tools and data. It allows AI clients to:

• Call tools (like search, memory, etc.)
• Access resources (like files, databases)
• Use prompts (predefined templates)

How Nexus Uses MCP

Nexus is an MCP server that provides:

• Tools: 13+ tools for docs, memory, servers, and stacks
• Resources: Not currently used
• Prompts: Not currently used

Prerequisites

API Key Required

All Nexus tool calls require an API key. Get one before setting up:

npx @nexus/cli auth login

Or create one at nexus.yogan.dev/dashboard/keys.

Quick Setup

The fastest way to set up Nexus with your AI client:

Terminal

npx @nexus/cli auth loginAuthenticated successfully!npx @nexus/cli initSelect clients to configure:> [x] Claude Desktop [x] Cursor

Manual Configuration

Add Nexus to your MCP client config:

{
  "mcpServers": {
    "nexus": {
      "command": "npx",
      "args": ["-y", "@nexus/cli", "serve"],
      "env": {
        "NEXUS_API_KEY": "nxs_your_api_key_here"
      }
    }
  }
}

Using CLI Login?

If you authenticated with `npx @nexus/cli auth login`, you can omit the `env` section - the CLI uses your stored key automatically.

Client-Specific Guides

• Claude Desktop
• Cursor
• VS Code
• OpenCode

HTTP Transport (Advanced)

For clients supporting HTTP/SSE transport:

URL: https://api.nexus.yogan.dev/mcp
Headers:
  Authorization: Bearer nxs_your_api_key_here

Troubleshooting

"API key required" or "Authentication required"

You need to authenticate:

npx @nexus/cli auth login

Or add your API key to the MCP config's env section.

"MCP server not responding"

1. Check your internet connection
2. Verify the config syntax (valid JSON)
3. Restart your AI client
4. Test the CLI directly: npx @nexus/cli serve

"Tool not found"

1. Ensure Nexus is properly configured
2. Check that the MCP server is running
3. Look for errors in client logs

Testing Your Setup

Run the CLI directly to verify it works:

Terminal

npx @nexus/cli serveNexus MCP server running...

If you see errors, check your API key and network connection.

Learn More

• MCP Specification
• MCP Servers Registry
• Authentication Guide