SharpMCP

SharpMCP.Core API Reference

Core abstractions, interfaces, and protocol types for building MCP servers.

Interfaces

IMcpTool

Core interface for all MCP tools.

public interface IMcpTool
{
    string Name { get; }
    string? Description { get; }
    Task<ToolResponse> ExecuteAsync(JsonElement? arguments, CancellationToken cancellationToken = default);
    JsonElement GetInputSchema();
}

IMcpServer

Main server interface for MCP server implementations.

public interface IMcpServer
{
    ServerInfo ServerInfo { get; }
    IReadOnlyList<Tool> Tools { get; }
    
    event EventHandler<ServerLifecycleEventArgs>? Started;
    event EventHandler<ServerLifecycleEventArgs>? Stopped;
    event EventHandler<ToolExecutionEventArgs>? ToolExecuted;
    
    void RegisterTool(IMcpTool tool);
    Task<ToolResponse> ExecuteToolAsync(string toolName, JsonElement? arguments, CancellationToken cancellationToken = default);
    Task StartAsync(CancellationToken cancellationToken = default);
    Task StopAsync(CancellationToken cancellationToken = default);
    Task RunAsync(CancellationToken cancellationToken = default);
}

IMcpTransport

Transport layer abstraction for different communication methods.

public interface IMcpTransport : IDisposable
{
    bool IsConnected { get; }
    event EventHandler<JsonRpcRequest>? RequestReceived;
    event EventHandler? Disconnected;
    
    Task ConnectAsync(CancellationToken cancellationToken = default);
    Task DisconnectAsync(CancellationToken cancellationToken = default);
    Task SendAsync(JsonRpcMessage message, CancellationToken cancellationToken = default);
}

IMcpServerBuilder

Fluent builder interface for server configuration.

public interface IMcpServerBuilder
{
    IMcpServerBuilder WithName(string name);
    IMcpServerBuilder WithVersion(string version);
    IMcpServerBuilder WithDescription(string description);
    IMcpServerBuilder WithOptions(McpServerOptions options);
    IMcpServerBuilder AddTool(IMcpTool tool);
    IMcpServer Build();
}

Base Classes

McpToolBase

Generic base class for strongly-typed tools.

public abstract class McpToolBase<TArgs> : IMcpTool where TArgs : class, new()
{
    public abstract string Name { get; }
    public abstract string? Description { get; }
    
    public virtual async Task<ToolResponse> ExecuteAsync(JsonElement? arguments, CancellationToken cancellationToken = default);
    public virtual JsonElement GetInputSchema();
    
    protected abstract Task<ToolResponse> ExecuteAsync(TArgs args, CancellationToken cancellationToken);
    protected virtual string? ValidateArguments(TArgs args);
    
    protected static ToolResponse Success(string text);
    protected static ToolResponse Success(ContentPart content);
    protected static ToolResponse Error(string error);
}

McpToolBase

Base class for tools without arguments.

public abstract class McpToolBase : IMcpTool
{
    public abstract string Name { get; }
    public abstract string? Description { get; }
    
    public virtual Task<ToolResponse> ExecuteAsync(JsonElement? arguments, CancellationToken cancellationToken = default);
    public virtual JsonElement GetInputSchema();
    
    protected abstract Task<ToolResponse> ExecuteAsync(CancellationToken cancellationToken);
    
    protected static ToolResponse Success(string text);
    protected static ToolResponse Success(ContentPart content);
    protected static ToolResponse Error(string error);
}

Protocol Types

JsonRpcRequest

Represents a JSON-RPC request message.

public class JsonRpcRequest : JsonRpcMessage
{
    public string Method { get; set; } = "";
    public JsonElement? Params { get; set; }
}

JsonRpcResponse

Represents a JSON-RPC response message.

public class JsonRpcResponse : JsonRpcMessage
{
    public JsonElement? Result { get; set; }
    public JsonRpcError? Error { get; set; }
}

ServerInfo

Contains server metadata and capabilities.

public class ServerInfo
{
    public string Name { get; set; } = "";
    public string Version { get; set; } = "";
    public string? Description { get; set; }
    public ServerCapabilities Capabilities { get; set; } = new();
}

Tool

Represents a tool definition in the MCP protocol.

public class Tool
{
    public string Name { get; set; } = "";
    public string? Description { get; set; }
    public JsonElement InputSchema { get; set; }
}

ToolResponse

Represents the response from tool execution.

public class ToolResponse
{
    public List<ContentPart> Content { get; set; } = [];
    public bool IsError { get; set; }
    
    public static ToolResponse FromContent(string text);
    public static ToolResponse FromError(string error);
}

ContentPart

Represents a piece of content in responses.

public class ContentPart
{
    public string Type { get; set; } = "text";
    public string Text { get; set; } = "";
}

Attributes

McpToolAttribute

Decorates classes to mark them as MCP tools.

[AttributeUsage(AttributeTargets.Class)]
public class McpToolAttribute : Attribute
{
    public string Name { get; }
    public string? Description { get; set; }
    
    public McpToolAttribute(string name);
}

JsonRequiredAttribute

Marks properties as required in JSON schema.

[AttributeUsage(AttributeTargets.Property)]
public class JsonRequiredAttribute : Attribute
{
}

JsonDescriptionAttribute

Provides descriptions for JSON schema properties.

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Class)]
public class JsonDescriptionAttribute : Attribute
{
    public string Description { get; }
    
    public JsonDescriptionAttribute(string description);
}

JsonStringConstraintsAttribute

Defines validation constraints for string properties.

[AttributeUsage(AttributeTargets.Property)]
public class JsonStringConstraintsAttribute : Attribute
{
    public int MinLength { get; set; } = -1;
    public int MaxLength { get; set; } = -1;
    public string? Pattern { get; set; }
    public string? Format { get; set; }
}

JsonNumberConstraintsAttribute

Defines validation constraints for numeric properties.

[AttributeUsage(AttributeTargets.Property)]
public class JsonNumberConstraintsAttribute : Attribute
{
    public double Minimum { get; set; }
    public double Maximum { get; set; }
    public bool HasMinimum { get; set; }
    public bool HasMaximum { get; set; }
}

JsonArrayConstraintsAttribute

Defines validation constraints for array properties.

[AttributeUsage(AttributeTargets.Property)]
public class JsonArrayConstraintsAttribute : Attribute
{
    public int MinItems { get; set; } = -1;
    public int MaxItems { get; set; } = -1;
    public bool UniqueItems { get; set; }
}

JsonEnumAttribute

Defines allowed enumeration values.

[AttributeUsage(AttributeTargets.Property)]
public class JsonEnumAttribute : Attribute
{
    public object[] Values { get; }
    
    public JsonEnumAttribute(params object[] values);
}

Utilities

ToolResponseBuilder

Fluent builder for creating tool responses.

public class ToolResponseBuilder
{
    public ToolResponseBuilder WithContent(string text);
    public ToolResponseBuilder WithTypedContent(string type, string text);
    public ToolResponseBuilder WithError(string error);
    public ToolResponse Build();
}

JsonSchemaGenerator

Generates JSON schemas from C# types.

public static class JsonSchemaGenerator
{
    public static JsonSchema GenerateSchema<T>();
    public static JsonSchema GenerateSchema(Type type);
}

Configuration

McpServerOptions

Configuration options for MCP servers.

public class McpServerOptions
{
    public string Name { get; set; } = "";
    public string Version { get; set; } = "1.0.0";
    public string? Description { get; set; }
    public int MaxConcurrentTools { get; set; } = 5;
    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(30);
    public bool EnableDetailedErrors { get; set; } = false;
}

Exceptions

McpToolException

Exception specific to tool execution errors.

public class McpToolException : Exception
{
    public McpToolException(string message);
    public McpToolException(string message, Exception innerException);
}

McpTransportException

Exception for transport-related errors.

public class McpTransportException : Exception
{
    public McpTransportException(string message);
    public McpTransportException(string message, Exception innerException);
}

Event Args

ServerLifecycleEventArgs

Event arguments for server lifecycle events.

public class ServerLifecycleEventArgs : EventArgs
{
    public DateTime Timestamp { get; }
    public ServerInfo ServerInfo { get; }
}

ToolExecutionEventArgs

Event arguments for tool execution events.

public class ToolExecutionEventArgs : EventArgs
{
    public string ToolName { get; }
    public TimeSpan Duration { get; }
    public bool Success { get; }
    public string? Error { get; }
    public DateTime Timestamp { get; }
}

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