MCP Routes

Plug Your Broker Into Any MCP Tool

MCP (Model Context Protocol) is an open standard that defines how applications communicate with external tool servers. MCP Routes let your Coreflux broker connect to any MCP-compatible server — file systems, messaging platforms, cloud storage, spreadsheets, and more — and call their tools directly from LoT Actions.

Like adding power tools to a workbench. Each MCP Route plugs a new tool into your broker — a Slack server for sending messages, a filesystem server for reading logs, a Google Drive server for cloud backups. Once connected, any LoT Action can pick up and use that tool.

Integration Architecture

MCP Routes allow the Coreflux Broker to connect to external MCP servers as a client. This enables LoT Actions to call tools provided by any MCP server—file systems, cloud services, communication platforms, and more.

How It Works

Define MCP Routes - Each route connects to an external MCP server
Discover Tools - The broker discovers available tools from each server
Call from Actions - Use CALL MCP in LoT Actions to invoke any tool
Reusable Connections - Multiple actions can share the same MCP route

MCP as a Connection Type. Just like database routes or REST API routes, MCP routes provide a reusable connection that any action can leverage. Define the route once, use it everywhere.

Basic Syntax

The MCP route type connects your Coreflux broker to an external MCP server, making that server’s tools callable from LoT Actions. Each route manages one MCP server connection, and you can define multiple routes to connect to different servers simultaneously.

DEFINE ROUTE MCPFilesystem WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "npx"
        WITH SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-filesystem, /data"
        WITH CLIENT_NAME "CorefluxFS"

Once connected, any LoT Action can use CALL MCP to invoke the server’s tools — send Slack messages, read and write files, generate spreadsheet reports, or interact with any other MCP-compatible service.

MCP Configuration

MCP_CONFIG Parameters

SERVER_COMMAND

string

MCP server command to execute (e.g., npx, python, node).

SERVER_ARGUMENTS

string

Comma-separated server arguments (e.g., -y, @modelcontextprotocol/server-filesystem).

CLIENT_NAME

string

MCP client identifier. Default: CorefluxBroker.

Configuration Examples

Filesystem Server
Custom MCP Server
Node.js Server

Enable LoT Actions to perform file operations:

DEFINE ROUTE MCPFilesystem WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "npx"
        WITH SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-filesystem, /data"
        WITH CLIENT_NAME "CorefluxFS"

Connect to a custom MCP server:

DEFINE ROUTE MCPCustom WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "python"
        WITH SERVER_ARGUMENTS "-m, my_mcp_server"
        WITH CLIENT_NAME "CorefluxCustom"

Run a Node.js MCP server:

DEFINE ROUTE MCPNode WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "node"
        WITH SERVER_ARGUMENTS "/opt/mcp/server.js, --config, /etc/mcp/config.json"
        WITH CLIENT_NAME "CorefluxNode"

MCP Server Examples

The MCP ecosystem includes servers for various platforms and services. These examples show how to connect popular MCP servers to your Coreflux broker for IoT integration.

Node.js Servers (npx)
Python Servers (uvx)

Node.js-based MCP servers can be run directly using npx. These are the most common and include official Anthropic servers.

Server	LoT Configuration	IoT Use Case
Filesystem	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-filesystem, /data"`	Read sensor logs, manage config files
Google Drive	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-gdrive"`	Cloud backup of IoT data
Slack	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-slack"`	Send alerts to team channels
Memory	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-memory"`	Persist context across AI sessions
Fetch	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-fetch"`	Access external APIs and web data
Windows Control	`SERVER_COMMAND "npx"` with `SERVER_ARGUMENTS "-y, mcp-control"`	Automate HMI/SCADA systems

Example: Slack Alerts for IoT Events

DEFINE ROUTE MCPSlack WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "npx"
        WITH SERVER_ARGUMENTS "-y, @modelcontextprotocol/server-slack"
        WITH CLIENT_NAME "CorefluxSlack"

Python-based MCP servers use uvx (the uv package runner). These are common for third-party integrations.

Server	LoT Configuration	IoT Use Case
Spotify	`SERVER_COMMAND "uvx"` with `SERVER_ARGUMENTS "spotify-mcp"`	Smart home audio control
Excel	`SERVER_COMMAND "uvx"` with `SERVER_ARGUMENTS "excel-mcp-server"`	Generate reports from sensor data

Example: Excel Reports from Sensor Data

DEFINE ROUTE MCPExcel WITH TYPE MCP
    ADD MCP_CONFIG
        WITH SERVER_COMMAND "uvx"
        WITH SERVER_ARGUMENTS "excel-mcp-server"
        WITH CLIENT_NAME "CorefluxExcel"

Calling MCP Tools

Once an MCP route is defined, you can call its tools from within LoT Actions using the CALL MCP syntax. This enables AI-powered automation triggered by MQTT events.

Basic Syntax

The standard syntax to invoke an MCP tool from an Action:

CALL MCP "RouteName.ToolName"
    WITH (arg1 = value1, arg2 = value2)
    RETURN AS {result_variable}

Component	Format	Description
Route.Tool	`"RouteName.ToolName"`	Route name and tool name separated by a dot
WITH	`WITH (name = value, ...)`	Named arguments in parentheses
RETURN AS	`RETURN AS {varname}`	Capture the result in a variable

Complete Example

This Action monitors a temperature sensor and uses an MCP tool to send a Slack message when the temperature exceeds a threshold:

DEFINE ACTION TemperatureAlert
ON TOPIC "sensors/+/temperature" DO
    SET "temp" WITH (GET JSON "value" IN PAYLOAD AS DOUBLE)
    SET "sensor_id" WITH TOPIC POSITION 2
    
    IF {temp} > 80 THEN
        CALL MCP "MCPSlack.send-message"
            WITH (channel = "alerts", message = "🔥 Sensor " + {sensor_id} + " at " + {temp} + "°C")
            RETURN AS {result}
        
        PUBLISH TOPIC "alerts/temperature/sent" WITH "Sensor: " + {sensor_id} + " Temp: " + {temp} + " Result: " + {result}
    END IF

Syntax Variations

No Arguments

Some tools don’t require arguments:

CALL MCP "MCPSystem.get-status"
    RETURN AS {status}

Multiple Arguments

Pass multiple named parameters:

CALL MCP "MCPFilesystem.write-file"
    WITH (path = "/data/log.txt", content = {payload}, append = true)
    RETURN AS {write_result}

String Concatenation

Build dynamic values using expressions:

CALL MCP "MCPSlack.send-message"
    WITH (message = "Device " + {device_id} + " reported: " + {value} + " at " + TIMESTAMP "UTC")
    RETURN AS {chat_result}

Tool Discovery

When an MCP route connects to a server, Coreflux automatically discovers all available tools and publishes them to MQTT system topics. This allows you to dynamically query what tools are available.

System Topics

Topic	Description
`$SYS/Coreflux/Routes/{RouteName}/Tools`	Summary of all tools for a route
`$SYS/Coreflux/Routes/{RouteName}/Tools/{ToolName}`	Detailed info for a specific tool

Tools Summary Payload

Subscribe to the summary topic to see all available tools:

{
  "route_name": "MCPSlack",
  "route_type": "MCP",
  "total_tools": 8,
  "tools": ["send-message", "list-channels", "get-channel-history", "add-reaction", ...],
  "timestamp": "2025-12-31T12:00:00.000Z"
}

Individual Tool Payload

Each tool publishes detailed metadata including parameters and usage examples:

{
  "name": "send-message",
  "route_name": "MCPSlack",
  "tool_type": "MCP",
  "description": "Send a message to a Slack channel",
  "parameters": {
    "channel": { "type": "string", "required": true },
    "message": { "type": "string", "required": true }
  },
  "usage_example": "CALL MCP \"MCPSlack.send-message\" WITH (channel = {channel}, message = {message}) RETURN AS {result}",
  "capability": {
    "execution_count": 42,
    "average_latency_ms": 150.25,
    "reliability_percent": 98.5
  },
  "timestamp": "2025-12-31T12:00:00.000Z"
}

Subscribing to Tool Discovery

Use MQTT Explorer or any MQTT client to discover available tools:

What to Find	Topic Pattern
All tools for a specific route	`$SYS/Coreflux/Routes/MCPSlack/Tools`
Details for a specific tool	`$SYS/Coreflux/Routes/MCPSlack/Tools/send-message`
All tools across all MCP routes	`$SYS/Coreflux/Routes/+/Tools/#`

Tool discovery topics are retained messages, so the information is immediately available when you subscribe—you don’t need to wait for the next update.

Use Cases

Alerting and Notifications

Connect to Slack, email, or other messaging MCP servers to send alerts directly from LoT Actions. When a sensor crosses a threshold, the Action calls the messaging tool — no external middleware needed.

File and Data Management

Use filesystem MCP servers to read configuration files, write sensor logs, or manage data exports. LoT Actions can read a config file at startup or append readings to a log file on every event.

Cloud Integration

Connect to Google Drive, Excel, or other cloud MCP servers to back up IoT data, generate reports from sensor readings, or sync configurations with cloud storage.

External Automation

Use Windows Control or custom MCP servers to automate HMI/SCADA interfaces, trigger external scripts, or interact with desktop applications as part of your IoT workflow.

Best Practices

Security Considerations

Limit MCP access to specific topics and actions
Use authentication for MCP server connections
Monitor MCP tool calls through logging
Implement rate limiting for MCP requests

Resource Management

Configure appropriate timeouts for MCP operations
Limit concurrent MCP connections if needed
Monitor memory usage of MCP server processes

Error Handling

Implement graceful fallbacks when the MCP server is unavailable
Log MCP communication errors for debugging
Set up alerts for repeated failures

Troubleshooting

MCP Server Won't Start

Verify SERVER_COMMAND path is correct
Check SERVER_ARGUMENTS syntax (comma-separated)
Ensure required packages are installed (npx, node, python)
Check system PATH includes required executables

Connection Timeout

Verify MCP server is running and responsive
Check network/firewall settings
Increase timeout values if server startup is slow
Check server logs for errors

Tool Execution Fails

Verify the requested tool is available
Check permissions for the operation
Review server logs for detailed error messages
Ensure broker has required access rights

Next Steps

REST API Routes

Connect to external REST APIs.

Python Integration

Add custom AI/ML logic with Python.

Quick Start

Developing and Managing Coreflux

Coreflux MQTT Broker

LoT Language

Product Updates

Plug Your Broker Into Any MCP Tool

Integration Architecture

How It Works

Basic Syntax

MCP Configuration

MCP_CONFIG Parameters

Configuration Examples

MCP Server Examples

Calling MCP Tools

Basic Syntax

Complete Example

Syntax Variations

Tool Discovery

System Topics

Tools Summary Payload

Individual Tool Payload

Subscribing to Tool Discovery

Use Cases

Best Practices

Troubleshooting

Next Steps

REST API Routes

Python Integration

​Plug Your Broker Into Any MCP Tool

​Integration Architecture

​How It Works

​Basic Syntax

​MCP Configuration

​MCP_CONFIG Parameters

​Configuration Examples

​MCP Server Examples

​Calling MCP Tools

​Basic Syntax

​Complete Example

​Syntax Variations

​Tool Discovery

​System Topics

​Tools Summary Payload

​Individual Tool Payload

​Subscribing to Tool Discovery

​Use Cases

​Best Practices

​Troubleshooting

​Next Steps

REST API Routes

Python Integration

Plug Your Broker Into Any MCP Tool

Integration Architecture

How It Works

Basic Syntax

MCP Configuration

MCP_CONFIG Parameters

Configuration Examples

MCP Server Examples

Calling MCP Tools

Basic Syntax

Complete Example

Syntax Variations

Tool Discovery

System Topics

Tools Summary Payload

Individual Tool Payload

Subscribing to Tool Discovery

Use Cases

Best Practices

Troubleshooting

Next Steps