MCP Server

Early Alpha Version

AI Agents are in early alpha. Node interfaces, behaviors, and APIs are subject to change.

The MCP Server node connects your agents to the Model Context Protocol (MCP) ecosystem. It works in two modes:

• Client — Connect to an external MCP server to consume its tools
• Server — Expose your own tools via MCP for external agents to use

Inputs

Input	Type	Default	Description
Mode	Enum	Client	Client (consume tools) or Server (expose tools)
Server URL	String	—	(Client) URL of the MCP server to connect to
Transport	Enum	SSE	(Client) Connection method: SSE, Stdio, or WebSocket
Command	String	—	(Client, Stdio) The command to execute for stdio transport
Arguments	String	—	(Client, Stdio) Command-line arguments
Headers	JSON	—	(Client) HTTP headers for authentication
Exposed Tools	Array	—	(Server) Tool definitions to expose via MCP
Server Port	Number	3100	(Server) Port to listen on
Connect	Signal	—	Trigger to establish the connection
Disconnect	Signal	—	Trigger to close the connection
Refresh Tools	Signal	—	Re-fetch the tool list from the server

Outputs

Output	Type	Description
Tools	Array	Tool definitions discovered from the MCP server
Tool Names	Array	Simple list of tool name strings
Connected	Boolean	Whether the connection is active
Status	String	Current connection status (disconnected, connecting, connected, error)
Server Info	Object	Information about the connected MCP server
Error	String	Error message if the connection failed
Connected	Signal	Fires when the connection is established
Disconnected	Signal	Fires when the connection is closed
Tools Updated	Signal	Fires when the tool list changes

Client Mode

Use Client mode to connect to external MCP servers and consume their tools.

SSE Transport

The most common transport. Connect to a server via HTTP Server-Sent Events:

1. Set Mode to Client
2. Set Transport to SSE
3. Enter the Server URL (e.g. http://localhost:3100/sse)
4. Add any required Headers (e.g. API keys)
5. Fire the Connect signal

Stdio Transport

For local MCP servers that run as command-line processes:

1. Set Transport to Stdio
2. Set the Command (e.g. npx)
3. Set Arguments (e.g. -y @modelcontextprotocol/server-filesystem /path/to/dir)
4. Fire Connect

WebSocket Transport

For real-time bidirectional communication:

1. Set Transport to WebSocket
2. Set the Server URL (e.g. ws://localhost:3100)
3. Fire Connect

Server Mode

Use Server mode to expose your own tools to external MCP clients:

1. Set Mode to Server
2. Wire Agent Tool definitions to the Exposed Tools input
3. Set the Server Port
4. Fire Connect to start the server

Using MCP Tools with Agents

Once connected, the Tools output contains tool definitions compatible with the AI Agent node:

[MCP Server] ─── Tools ──→ [Agent] (Tools input)

Alternatively, place the MCP Server in the same component as an Agent — auto-discovery will find the tools automatically.

Usage Tips

• The MCP ecosystem has hundreds of pre-built servers for databases, APIs, file systems, and more
• Use Refresh Tools if the remote server's tool list changes while connected
• In Server mode, you can expose any XGENIA logic as an MCP-compatible tool server
• Check the Status output to show connection state in your UI