This is a simple multithread WebServer supporting simple controller and event based calls.
Perfect for .NET nanoFramework REST API based project. Support all type of Http Methods.
Perfect for simple embedded web pages, with Support of file on a storage (USB, SD Card, in Memory).
Supports both HTTPS and HTTP.
Use this version if you want to serve local files and have support for System.IO.FileSystem on your device.
Otherwise use 'nanoFramework.WebServer' nuget.
.NET nanoFramework WebServer with Model Context Protocol (MCP)
Build status
Component
Build Status
NuGet Package
nanoFramework.WebServer
nanoFramework.WebServer.FileSystem
nanoFramework.WebServer.Mcp
Overview
This library provides a lightweight, multi-threaded HTTP/HTTPS WebServer for .NET nanoFramework with comprehensive Model Context Protocol (MCP) support for AI agent integration.
Key Features
Multi-threaded request handling
Static file serving with FileSystem support
RESTful API support with parameter handling
Route-based controllers with attribute decoration
Authentication support (Basic, API Key)
HTTPS/SSL support with certificates
Model Context Protocol (MCP) for AI agent integration
Automatic tool discovery and JSON-RPC 2.0 compliance
Quick Start
Basic Event Based WebServer
Using the Web Server is very straight forward and supports event based calls.
// You need to be connected to a Wi-Fi or ethernet connection with a proper IP Address
// Optionally you can pass a parameter with the IP address for the server to bind to
using (WebServer server = new WebServer(80, HttpProtocol.Http))
{
server.CommandReceived += ServerCommandReceived;
server.Start();
Thread.Sleep(Timeout.Infinite);
}
private static void ServerCommandReceived(object source, WebServerEventArgs e)
{
if (e.Context.Request.RawUrl.ToLower() == "/hello")
{
WebServer.OutputAsStream(e.Context.Response, "Hello from nanoFramework!");
}
else
{
WebServer.OutputHttpCode(e.Context.Response, HttpStatusCode.NotFound);
}
}
Controller-Based WebServer
Controllers are supported including with parametarized routes like 'api/led/{id}/dosomething/{order}'.
using (WebServer server = new WebServer(80, HttpProtocol.Http, new Type[] { typeof(MyController) }))
{
server.Start();
Thread.Sleep(Timeout.Infinite);
}
public class MyController
{
[Route("api/hello")]
[Method("GET")]
public void Hello(WebServerEventArgs e)
{
WebServer.OutputAsStream(e.Context.Response, "Hello from Controller!");
}
[Route("api/led/{id}")]
[Method("GET")]
public void LedState(WebServerEventArgs e)
{
string ledId = e.GetRouteParameter("id");
WebServer.OutputAsStream(e.Context.Response, $"You selected Led {ledId}!");
}
}
Model Context Protocol (MCP) Support
Enable AI agents to interact with your embedded devices through standardized tools and JSON-RPC 2.0 protocol.
Defining MCP Tools
public class IoTTools
{
[McpServerTool("read_sensor", "Reads temperature from sensor")]
public static string ReadTemperature()
{
// Your sensor reading code
return "23.5°C";
}
[McpServerTool("control_led", "Controls device LED", "Uutput the statusof the LED")]
public static string ControlLed(LedCommand command)
{
// Your LED control code
return $"LED set to {command.State}";
}
}
public class LedCommand
{
[Description("LED state: on, off, or blink")]
public string State { get; set; }
}
Defining MCP Prompts
You can define reusable, high-level prompts for AI agents using the McpServerPrompt attribute. Prompts encapsulate multi-step instructions or workflows that can be invoked by agents.
Here's a simple example:
using nanoFramework.WebServer.Mcp;
public class McpPrompts
{
[McpServerPrompt("echo_sanity_check", "Echo test prompt")]
public static PromptMessage[] EchoSanityCheck()
{
return new PromptMessage[]
{
new PromptMessage("Call Echo with the string 'Hello MCP world!' and return the response.")
};
}
}
Prompts can be discovered and invoked by AI agents in the same way as tools. You can also define prompts with parameters using the McpPromptParameter attribute.
Setting Up MCP Server
public static void Main()
{
// Connect to WiFi first
var connected = WifiNetworkHelper.ConnectDhcp(Ssid, Password, requiresDateTime: true);
// Discover and register MCP tools
McpToolRegistry.DiscoverTools(new Type[] { typeof(IoTTools) });
// Discover and register MCP prompts
McpPromptRegistry.DiscoverPrompts(new Type[] { typeof(McpPrompts) });
// Start WebServer with MCP support
using (var server = new WebServer(80, HttpProtocol.Http, new Type[] { typeof(McpServerController) }))
{
// Optional customization
McpServerController.ServerName = "MyIoTDevice";
McpServerController.Instructions = "IoT device with sensor and LED control capabilities.";
server.Start();
Thread.Sleep(Timeout.Infinite);
}
}
AI Agent Integration
Once running, AI agents can discover and invoke your tools:
No compression support in request/response streams
MCP implementation supports server features only (no notifications or SSE)
No or single parameter limitation for MCP tools (use complex objects for multiple parameters)
Prompt parameters, when declared, are always mandatory.
Installation
Install 'nanoFramework.WebServer' for the Web Server without File System support. Install 'nanoFramework.WebServer.FileSystem' for file serving, so with devices supporting File System.
Install 'nanoFramework.WebServer.Mcp' for MCP support. It does contains the full 'nanoFramework.WebServer' but does not include native file serving. You can add this feature fairly easilly by reusing the code function serving it.
Contributing
For documentation, feedback, issues and contributions, please refer to the Home repo.
This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behaviour in our community.
For more information see the .NET Foundation Code of Conduct.
