Class McpServer

Namespace: LMKit.Mcp.Server

Assembly: LM-Kit.NET.dll

Hosts a Model Context Protocol server: it exposes registered tools and resources to an MCP client and answers JSON-RPC messages.

[Obfuscation(Exclude = true)]
public sealed class McpServer

Inheritance: object

McpServer

Inherited Members: object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

var server = new McpServer(new McpServerOptions { Name = "my-server", Version = "1.0.0" });
server.RegisterTool(new MyTool());

string reply = await server.HandleMessageAsync(incomingJson, new McpRequestContext());

Remarks

The server is transport-agnostic. It consumes a JSON-RPC message and produces the reply, so a host can drive it over HTTP, over standard input and output, or over any other channel. McpStdioServer provides the standard input and output loop.

Tools are ordinary ITool implementations. A tool that also implements IToolMetadata has its MCP annotations derived from its declared side effect and idempotence, and becomes governable through PermissionPolicy. A tool that implements IMcpTool may additionally return images, resource links, and a structured projection.

Constructors

McpServer(McpServerOptions): Initializes a new server.

Fields

DefaultProtocolVersion: The protocol revision this implementation targets.

Properties

Capabilities: Gets the capabilities this server advertises, derived from what is actually registered.

LogLevel: Gets the minimum severity the client has asked to receive. Defaults to Info; a server should not send anything below it.

Options: Gets the options this server was created with.

PermissionPolicy: Gets or sets the policy deciding which registered tools are exposed and callable. When null, every registered tool is exposed.

Tools: Gets the tools currently exposed, after the permission policy has been applied.

Methods

BuildLogNotification(McpLogLevel, string, string): Builds a notifications/message log message. Hosts push this over the server-to-client channel and drop anything below LogLevel.

BuildProgressNotification(string, double, double?, string): Builds a notifications/progress message. Hosts push this to the client over whatever channel carries server-initiated messages.

BuildToolListChangedNotification(): Builds a notifications/tools/list_changed message, sent when the exposed tool set changes so a live session does not have to reconnect to see it.

HandleMessageAsync(string, McpRequestContext, CancellationToken): Handles one incoming JSON-RPC message and produces the reply.

RegisterCompletionProvider(IMcpCompletionProvider): Registers an argument-completion provider. Providers are consulted in registration order until one answers.

RegisterPromptProvider(IMcpPromptProvider): Registers a prompt provider. Providers are consulted in registration order until one claims the prompt being expanded.

RegisterResourceProvider(IMcpResourceProvider): Registers a resource provider. Providers are consulted in registration order until one claims the URI being read.

RegisterTool(ITool): Registers a tool. Registering a name that is already present replaces the previous tool.

UnregisterTool(string): Removes a tool by name.

Events

LogLevelChanged: Raised when a client sets its minimum log level through logging/setLevel. Hosts use it to start or stop forwarding log messages.

ToolListChanged: Raised when the exposed tool set changes. Hosts forward this as a notifications/tools/list_changed notification so live sessions pick up the change without reconnecting.

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