MCP Discovery

NexusIDE includes a built-in browser for discovering and connecting to Model Context Protocol (MCP) servers. MCP extends NexusCore's capabilities by providing access to external tools and data sources.

What is MCP?

The Model Context Protocol is a standardized interface that allows AI agents to interact with external tools and data sources. MCP servers expose tools that NexusCore can use during agent sessions — databases, APIs, file systems, and more.

Browsing MCP Servers

1. Open the MCP panel from the activity bar (left sidebar)
2. Browse available servers by category
3. View each server's description, available tools, and connection requirements
4. Click Connect to add a server to your workspace

Configuring MCP Servers

MCP servers are configured in your workspace's .nexuscore/mcp.json:

{
  "servers": [
    {
      "name": "my-database",
      "transport": "stdio",
      "command": "npx",
      "args": ["@modelcontextprotocol/server-postgres", "postgresql://localhost/mydb"]
    },
    {
      "name": "github",
      "transport": "stdio",
      "command": "npx",
      "args": ["@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_TOKEN": "${env:GITHUB_TOKEN}"
      }
    },
    {
      "name": "custom-api",
      "transport": "sse",
      "url": "http://localhost:3001/mcp"
    }
  ]
}

Transport Types

Transport	Description	Use Case
stdio	Communicates via stdin/stdout with a local process	Most MCP servers
sse	Connects via Server-Sent Events over HTTP	Remote or web-based servers

Using MCP Tools

Once an MCP server is connected, its tools appear in the agent's tool list. The agent can use them automatically during sessions:

You: Query the database for all users created this week

NexusCore: I'll use the database MCP server to run that query.
[Tool: mcp_my-database.query] SELECT * FROM users WHERE created_at > now() - interval '7 days'

Found 23 users created this week...

MCP tools follow the same approval policies as built-in tools. By default, MCP tools require approval before each execution.

Managing Connections

From NexusIDE

The MCP panel shows all configured servers with their connection status:

• 🟢 Connected — Server is running and responsive
• 🔴 Disconnected — Server is not reachable
• 🟡 Connecting — Connection in progress

Click a server to view its available tools, or click Disconnect to remove it.

From NexusCore CLI

# List connected MCP servers
nexus-cli mcp list

# Add a server
nexus-cli mcp add my-server --transport stdio --command "npx @modelcontextprotocol/server-postgres"

# Remove a server
nexus-cli mcp remove my-server

Private MCP Servers (Studio)

Studio tier organizations can provision private, hosted MCP servers managed by Nexus Suite:

• Servers run in isolated containers with network access restricted to authenticated organization members
• Deploy from a Git repository URL or a pre-built container image
• Up to 5 private MCP server instances per organization
• RBAC controls which team members can access each server

Manage private MCP servers from the organization admin dashboard on the Portal, or via the MCP Hosting API.

Connecting to a Private MCP Server

{
  "servers": [
    {
      "name": "team-database",
      "transport": "sse",
      "url": "wss://mcp.nexus-suite.dev/mcp_abc123",
      "auth": "nexus-suite"
    }
  ]
}

When auth is set to "nexus-suite", NexusIDE automatically authenticates using your JWT and verifies RBAC permissions.

Tips

• Start with community MCP servers for common integrations (databases, GitHub, Slack)
• Use stdio transport for local servers — it's simpler and doesn't require a running HTTP server
• Use sse transport for remote servers or when multiple clients need to share a connection
• Review MCP tool permissions in Settings → NexusCore → Trust & Approvals