MCPClient Class

Properties   Methods   Events   Config Settings   Errors  

Provides an easy way to retrieve prompts, resources, and invoke tools from Model Context Protocol (MCP) servers.

Syntax

MCPClient

Remarks

The MCPClient class provides a simple way to communicate with MCP Servers.

Connecting to a Server

When the Transport property is set to ttStdio, the LocalServerPath property must first be set to a file path pointing to a server executable. The Timeout property can be used to specify a timeout when connecting to the server. To initiate the connection, the Connect method should be used.

If successful, the class will then launch the server executable as a subprocess and will be able to send and receive MCP requests.

// Server executable. client.LocalServerPath = @"PATH\\TO\\SERVER\\EXE"; // Launches the server .exe as a subprocess and connects to it. client.Connect();

Key Features

The MCPClient class supports all major MCP functionality, including tools, prompts, resources, and sampling.

Tools

Tools provide an opportunity for LLM clients to execute custom code, interact with external systems, and access dynamic or external data. Anything for which a function can be written can also be exposed as a tool. Common examples include database queries, file operations, or computations.

Listing Tools

Before a client can begin invoking tools, it should first know which tools are available on the server. A client can retrieve a list of valid tools via the ListTools method. When called, the Tools properties will be automatically cleared and populated with the retrieved tools.

Each tool contains a Name, which acts as a unique identifier that can be used to reference the tool.

// Request a list of tools on the server. client.ListTools(); // Display the name of each tool. foreach (var tool in client.Tools) { // A unique identifier for the tool. string name = tool.Name; // A natural language description of the tool. This is often used to allow LLMs to reason over. string description = tool.Description; // Write to 'stderr' as 'stdio' is reserved for client/server communications. Console.Error.WriteLine($"Tool name: {name}"); Console.Error.WriteLine($"Tool description: {description}"); }

Invoking Tools

Once a tool has been identified, it can be invoked using the InvokeTool method. The server will then reply with a list of individual tool messages that can be retrieved via the ToolMessages properties.

Each tool message contains a ToolMessageType indicating the type of response and a Value, which is typically plain text (e.g., a string result or a base64-encoded image).

// Invoke a tool named 'get-weather'. client.InvokeTool("get-weather"); // Write to 'stderr' as 'stdio' is reserved for client/server communications. foreach (var message in client.ToolMessages) { Console.Error.WriteLine($"message.Value"); }

Tool Parameters

Some server implementations allow tools to receive runtime parameters, allowing clients to provide additional data or context at the time of invocation. These parameters can be specified by calling the AddToolParam method prior to calling the InvokeTool method. Each parameter consists of a Name and a Value, which are then passed along to the server with the tool request.

// Set up parameters for the 'get-weather' tool. client.AddToolParam("location", "New York"); client.AddToolParam("units", "metric"); // Invoke the tool with the specified parameters. client.InvokeTool("get-weather"); // The response will contain the weather information for New York in metric units. // Write to 'stderr' as 'stdio' is reserved for client/server communications. foreach (var message in client.ToolMessages) { Console.Error.WriteLine($"Tool response: {message.Value}"); }

Prompts

Prompts are predefined conversation starters or instructions that can be quickly inserted into the LLM's context to guide specific interactions or workflows. Prompts serve as standardized templates for common conversational patterns and allow for consistent responses for tasks like reviewing code, analyzing data, or answering specific types of questions.

Listing Prompts

Before a client can begin retrieving prompts, it should first know which prompts are available on the server. A client can retrieve a list of available prompts via the ListPrompts method. When called, the Prompts properties will be automatically cleared and populated with the retrieved prompts.

client.ListPrompts(); // Write to 'stderr' as 'stdio' is reserved for client/server communications. foreach (var prompt in client.Prompts) { Console.Error.WriteLine($"Prompt name: {prompt.Name}"); Console.Error.WriteLine($"Description: {prompt.Description}"); }

Retrieving Prompts

Once a prompt has been identified, it can be requested using the GetPrompt method. The server will then reply with a list of individual prompt messages that will be available via the PromptMessages properties.

Each prompt message consists of Text and a Role. A Role identifies the speaker or author of a given message, and its Text represents a natural language instruction that can be fed into a language model.

client.GetPrompt("review-code"); // Write to 'stderr' as 'stdio' is reserved for client/server communications. for (var message in client.PromptMessages) { // A role of '0' indicates a prompt message coming from a 'user'. // A value of '1' indicates that it comes from an 'assistant'. string direction = (message.Role == 0) ? "User" : "Assistant"; Console.Error.WriteLine($"Message from {direction}: {message.Text}"); }

Prompt Parameters

Some server implementations support runtime arguments. These parameters allow prompts to be customized with client-specific data before execution. Prompt parameters can be specified by calling the AddPromptParam method before calling the GetPrompt method.

Each parameter consists of a Name and a Value, which are then passed along to the server with the prompt request.

// Request a prompt named 'review-code', passing along the following parameters: // code-language: 'javascript' // code-to-review: 'var a = 5;' client.AddPromptParam("code-language", "javascript"); client.AddPromptParam("code-to-review", "var a = 5;"); client.GetPrompt("review-code"); // The server would then return a code review of the javascript code 'var a = 5;'. // Write to 'stderr' as 'stdio' is reserved for client/server communications. Console.Error.WriteLine($"{client.PromptMessages[0].Text}");

Resources

Resources provide persistent, read-only content that can be requested once by the user and reused throughout the session. These are typically static files such as documentation, source code, or other reference materials that help provide context for LLM interactions.

Listing Resources

Before a client can begin retrieving resources, it should first know which resources are available on the server. A client can retrieve a list of available resources via the ListResources method. When called, the Resources properties will be automatically cleared and populated with the retrieved resources.

Each resource contains a Uri, which acts as a unique identifier that can be used to fetch its contents. Resources may also have a Name and a natural language Description, which are typically used to provide language models context over what each resource represents.

client.ListResources(); // Write to 'stderr' as 'stdio' is reserved for client/server communications. foreach (var resource in client.Resources) { Console.Error.WriteLine($"Resource name: {resource.Name}"); Console.Error.WriteLine($"Description: {resource.Description}"); Console.Error.WriteLine($"URI: {resource.Uri}"); }

Retrieving Resources

Once a resource has been identified, its contents can be retrieved using the ReadResource method. The server will then reply with the resource contents that can be retrieved via the ResourceContents properties.

// Resources are identified by URIs. In this case, this resource can be identified with 'file:///docs/reference.txt'. client.ReadResource("file:///docs/reference.txt"); // Write to 'stderr' as 'stdio' is reserved for client/server communications. foreach (var content in client.ResourceContents) { Console.Error.WriteLine($"Resource content (text): {content.Data}"); }

Disconnecting from a Server

To disconnect from the server, the Disconnect method should be used. When the Transport property is set to ttStdio, the client will drop the underlying connection and the server subprocess will be automatically terminated. client.Disconnect();

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

LocalServerPath Property (MCPClient Class)

The path to the local MCP server executable.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetLocalServerPath();
int SetLocalServerPath(const char* lpszLocalServerPath);

Unicode (Windows)
LPWSTR GetLocalServerPath();
INT SetLocalServerPath(LPCWSTR lpszLocalServerPath);

char* mcpsdk_mcpclient_getlocalserverpath(void* lpObj);
int mcpsdk_mcpclient_setlocalserverpath(void* lpObj, const char* lpszLocalServerPath);

QString getLocalServerPath();
int setLocalServerPath(QString qsLocalServerPath);

Default Value

""

Remarks

When the Transport property is set to ttStdio, this property is used to specify the full path to the local MCP server executable that the class will launch and connect to. When set, the class will start the server process at the specified path and establish a connection for MCP operations.

The supplied path must point to a valid MCP server executable file. If the path is empty or invalid, the class will not attempt to start a local server process.

Data Type

String

PromptMessages Property (MCPClient Class)

A collection of prompt messages received after a prompt request.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKPromptMessage>* GetPromptMessages();
int SetPromptMessages(MCPSDKList<MCPSDKPromptMessage>* val);

int mcpsdk_mcpclient_getpromptmessagecount(void* lpObj);
int mcpsdk_mcpclient_setpromptmessagecount(void* lpObj, int iPromptMessageCount);

int mcpsdk_mcpclient_getpromptmessagerole(void* lpObj, int promptmessageindex);
int mcpsdk_mcpclient_setpromptmessagerole(void* lpObj, int promptmessageindex, int iPromptMessageRole);

char* mcpsdk_mcpclient_getpromptmessagetext(void* lpObj, int promptmessageindex);
int mcpsdk_mcpclient_setpromptmessagetext(void* lpObj, int promptmessageindex, const char* lpszPromptMessageText);

int getPromptMessageCount();
int setPromptMessageCount(int iPromptMessageCount);

int getPromptMessageRole(int iPromptMessageIndex);
int setPromptMessageRole(int iPromptMessageIndex, int iPromptMessageRole);

QString getPromptMessageText(int iPromptMessageIndex);
int setPromptMessageText(int iPromptMessageIndex, QString qsPromptMessageText);

Remarks

This collection holds a list of PromptMessage items.

Calling the GetPrompt method will populate this collection with a list of prompt messages received from the server.

This property is not available at design time.

Data Type

MCPSDKPromptMessage

Prompts Property (MCPClient Class)

A collection of prompts available on the server.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKPrompt>* GetPrompts();

int mcpsdk_mcpclient_getpromptcount(void* lpObj);

char* mcpsdk_mcpclient_getpromptdescription(void* lpObj, int promptindex);

char* mcpsdk_mcpclient_getpromptname(void* lpObj, int promptindex);

int getPromptCount();

QString getPromptDescription(int iPromptIndex);

QString getPromptName(int iPromptIndex);

Remarks

This collection holds a list of Prompt items.

Calling the ListPrompts method will populate this collection with a list of prompts received from the server.

This property is read-only and not available at design time.

Data Type

MCPSDKPrompt

ResourceContents Property (MCPClient Class)

A collection of resource contents received after a resource read request.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKResourceContent>* GetResourceContents();
int SetResourceContents(MCPSDKList<MCPSDKResourceContent>* val);

int mcpsdk_mcpclient_getresourcecontentcount(void* lpObj);
int mcpsdk_mcpclient_setresourcecontentcount(void* lpObj, int iResourceContentCount);

int mcpsdk_mcpclient_getresourcecontentdata(void* lpObj, int resourcecontentindex, char** lpResourceContentData, int* lenResourceContentData);
int mcpsdk_mcpclient_setresourcecontentdata(void* lpObj, int resourcecontentindex, const char* lpResourceContentData, int lenResourceContentData);

char* mcpsdk_mcpclient_getresourcecontentmimetype(void* lpObj, int resourcecontentindex);
int mcpsdk_mcpclient_setresourcecontentmimetype(void* lpObj, int resourcecontentindex, const char* lpszResourceContentMimeType);

char* mcpsdk_mcpclient_getresourcecontenturi(void* lpObj, int resourcecontentindex);
int mcpsdk_mcpclient_setresourcecontenturi(void* lpObj, int resourcecontentindex, const char* lpszResourceContentUri);

int getResourceContentCount();
int setResourceContentCount(int iResourceContentCount);

QByteArray getResourceContentData(int iResourceContentIndex);
int setResourceContentData(int iResourceContentIndex, QByteArray qbaResourceContentData);

QString getResourceContentMimeType(int iResourceContentIndex);
int setResourceContentMimeType(int iResourceContentIndex, QString qsResourceContentMimeType);

QString getResourceContentUri(int iResourceContentIndex);
int setResourceContentUri(int iResourceContentIndex, QString qsResourceContentUri);

Remarks

This collection holds a list of ResourceContent items.

Calling the ReadResource method will populate this collection with a list of resource contents received from the server.

This property is not available at design time.

Data Type

MCPSDKResourceContent

Resources Property (MCPClient Class)

A collection of resources available on the server.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKResource>* GetResources();

int mcpsdk_mcpclient_getresourcecount(void* lpObj);

char* mcpsdk_mcpclient_getresourcedescription(void* lpObj, int resourceindex);

char* mcpsdk_mcpclient_getresourcemimetype(void* lpObj, int resourceindex);

char* mcpsdk_mcpclient_getresourcename(void* lpObj, int resourceindex);

int mcpsdk_mcpclient_getresourcesize(void* lpObj, int resourceindex);

char* mcpsdk_mcpclient_getresourceuri(void* lpObj, int resourceindex);

int getResourceCount();

QString getResourceDescription(int iResourceIndex);

QString getResourceMimetype(int iResourceIndex);

QString getResourceName(int iResourceIndex);

int getResourceSize(int iResourceIndex);

QString getResourceUri(int iResourceIndex);

Remarks

This collection holds a list of Resource items.

Calling the ListResources method will populate this collection with a list of resources received from the server.

This property is read-only and not available at design time.

Data Type

MCPSDKResource

SamplingMessages Property (MCPClient Class)

A collection of messages received when the server requests language model generation.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKSamplingMessage>* GetSamplingMessages();
int SetSamplingMessages(MCPSDKList<MCPSDKSamplingMessage>* val);

int mcpsdk_mcpclient_getsamplingmessagecount(void* lpObj);
int mcpsdk_mcpclient_setsamplingmessagecount(void* lpObj, int iSamplingMessageCount);

int mcpsdk_mcpclient_getsamplingmessagerole(void* lpObj, int samplingmessageindex);

char* mcpsdk_mcpclient_getsamplingmessagetext(void* lpObj, int samplingmessageindex);
int mcpsdk_mcpclient_setsamplingmessagetext(void* lpObj, int samplingmessageindex, const char* lpszSamplingMessageText);

int getSamplingMessageCount();
int setSamplingMessageCount(int iSamplingMessageCount);

int getSamplingMessageRole(int iSamplingMessageIndex);

QString getSamplingMessageText(int iSamplingMessageIndex);
int setSamplingMessageText(int iSamplingMessageIndex, QString qsSamplingMessageText);

Remarks

This collection holds a list of SamplingMessage items.

When the Transport property is set to ttStdio, this collection is populated when the server initiates a sampling request and represents a list of messages meant to be passed into the client's language model.

This property is not available at design time.

Data Type

MCPSDKSamplingMessage

Timeout Property (MCPClient Class)

The timeout for operations in seconds.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetTimeout();
int SetTimeout(int iTimeout);

Unicode (Windows)
INT GetTimeout();
INT SetTimeout(INT iTimeout);

int mcpsdk_mcpclient_gettimeout(void* lpObj);
int mcpsdk_mcpclient_settimeout(void* lpObj, int iTimeout);

int getTimeout();
int setTimeout(int iTimeout);

Default Value

10

Remarks

This property specifies the timeout period in seconds for operations performed by the class.

If this is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.

If this is set to a positive value, the class will wait for the operation to complete before returning control. If the timeout expires before the operation completes, the class throws an exception.

Note that all timeouts are inactivity timeouts, meaning the timeout period is extended by value specified in this property when any amount of data is successfully sent or received.

This property is not available at design time.

Data Type

Integer

ToolMessages Property (MCPClient Class)

A collection of tool messages received after a tool invocation.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKToolMessage>* GetToolMessages();
int SetToolMessages(MCPSDKList<MCPSDKToolMessage>* val);

int mcpsdk_mcpclient_gettoolmessagecount(void* lpObj);
int mcpsdk_mcpclient_settoolmessagecount(void* lpObj, int iToolMessageCount);

int mcpsdk_mcpclient_gettoolmessagemessagetype(void* lpObj, int toolmessageindex);

char* mcpsdk_mcpclient_gettoolmessagevalue(void* lpObj, int toolmessageindex);
int mcpsdk_mcpclient_settoolmessagevalue(void* lpObj, int toolmessageindex, const char* lpszToolMessageValue);

int getToolMessageCount();
int setToolMessageCount(int iToolMessageCount);

int getToolMessageMessageType(int iToolMessageIndex);

QString getToolMessageValue(int iToolMessageIndex);
int setToolMessageValue(int iToolMessageIndex, QString qsToolMessageValue);

Remarks

This collection holds a list of ToolMessage items.

Calling the InvokeTool method will populate this collection with a list of tool messages received from the server.

This property is not available at design time.

Data Type

MCPSDKToolMessage

Tools Property (MCPClient Class)

A collection of tools available on the server.

Syntax

• C++
• C
• Qt

MCPSDKList<MCPSDKTool>* GetTools();

int mcpsdk_mcpclient_gettoolcount(void* lpObj);

char* mcpsdk_mcpclient_gettooldescription(void* lpObj, int toolindex);

char* mcpsdk_mcpclient_gettoolname(void* lpObj, int toolindex);

int getToolCount();

QString getToolDescription(int iToolIndex);

QString getToolName(int iToolIndex);

Remarks

This collection holds a list of Tool items.

Calling the ListTools method will populate this collection with a list of tools received from the server.

This property is read-only and not available at design time.

Data Type

MCPSDKTool

Transport Property (MCPClient Class)

The transport mechanism used for communication.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetTransport();
int SetTransport(int iTransport);

Unicode (Windows)
INT GetTransport();
INT SetTransport(INT iTransport);

TT_STDIO(1), 
TT_HTTP(2)

int mcpsdk_mcpclient_gettransport(void* lpObj);
int mcpsdk_mcpclient_settransport(void* lpObj, int iTransport);

int getTransport();
int setTransport(int iTransport);

Default Value

1

Remarks

This property indicates whether the class operates via the standard input/output or HTTP transport mechanism. Possible values are as follows:

• ttStdio (1, default): Enables communication through standard input and output streams, but the class is limited to serving a single client at once due to the server acting as a subprocess of a client application.
• ttHTTP (2): Enables communication via HTTP requests and responses, and allows the class to serve multiple clients at once.

This property is not available at design time.

Data Type

Integer

AddPromptParam Method (MCPClient Class)

Adds a prompt parameter.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int AddPromptParam(const char* lpszName, const char* lpszValue);

Unicode (Windows)
INT AddPromptParam(LPCWSTR lpszName, LPCWSTR lpszValue);

int mcpsdk_mcpclient_addpromptparam(void* lpObj, const char* lpszName, const char* lpszValue);

int addPromptParam(const QString& qsName, const QString& qsValue);

Remarks

This method is used to add a parameter to be passed into the next prompt request. When called, the specified parameter value will be included in the next prompt requested via the GetPrompt method.

Name specifies the unique name identifier of the parameter.

Value specifies the value of the parameter that will be included in the prompt request.

Example: client.AddPromptParam("code-to-review", "var a = 5;"); client.GetPrompt("review-code"); // Write to 'stderr' as 'stdio' is reserved for client/server communications. Console.Error.WriteLine(client.PromptMessages[0].Text);

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

AddToolParam Method (MCPClient Class)

Adds a tool parameter.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int AddToolParam(const char* lpszName, const char* lpszValue);

Unicode (Windows)
INT AddToolParam(LPCWSTR lpszName, LPCWSTR lpszValue);

int mcpsdk_mcpclient_addtoolparam(void* lpObj, const char* lpszName, const char* lpszValue);

int addToolParam(const QString& qsName, const QString& qsValue);

Remarks

This method is used to add a parameter to be passed into the next tool invocation. When called, the specified parameter value will be included in the next tool invoked via the InvokeTool method.

Name specifies the unique name identifier of the parameter.

Value specifies the value of the parameter that will be included in the tool request.

Example: client.AddToolParam("location", "New York"); // The 'get-weather' tool will receive a 'location' parameter with a value of 'New York'. client.InvokeTool("get-weather"); // Write to 'stderr' as 'stdio' is reserved for client/server communications. Console.Error.WriteLine(client.ToolMessages[0].Value);

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Config Method (MCPClient Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* mcpsdk_mcpclient_config(void* lpObj, const char* lpszConfigurationString);

QString config(const QString& qsConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Connect Method (MCPClient Class)

Connects to a MCP server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Connect();

Unicode (Windows)
INT Connect();

int mcpsdk_mcpclient_connect(void* lpObj);

int connect();

Remarks

This method is used to establish a connection to a MCP server and initializes the communication channel. After establishing the connection, the initialize request is automatically sent to the server.

If the Transport property is set to ttStdio, this method will start the server as a subprocess using the path specified in the LocalServerPath property and enable communication through standard input/output streams.

This method will throw an exception if the connection cannot be established or if the server initialization fails.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Disconnect Method (MCPClient Class)

Disconnects from a MCP server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Disconnect();

Unicode (Windows)
INT Disconnect();

int mcpsdk_mcpclient_disconnect(void* lpObj);

int disconnect();

Remarks

This method is used to close the connection to a MCP server and terminates the communication channel. All active operations will be canceled and any pending requests will be discarded.

If the Transport property is set to ttStdio, this method will also terminate the server subprocess that was started during connection.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

GetPrompt Method (MCPClient Class)

Retrieves a prompt from the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetPrompt(const char* lpszName);

Unicode (Windows)
INT GetPrompt(LPCWSTR lpszName);

int mcpsdk_mcpclient_getprompt(void* lpObj, const char* lpszName);

int getPrompt(const QString& qsName);

Remarks

This method is used to request a prompt from the server. When called, the PromptMessages properties will be cleared and populated with the individual messages that make up the requested prompt.

Name specifies the unique name identifier of the prompt that will be retrieved.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

InvokeTool Method (MCPClient Class)

Invokes a tool from the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int InvokeTool(const char* lpszName);

Unicode (Windows)
INT InvokeTool(LPCWSTR lpszName);

int mcpsdk_mcpclient_invoketool(void* lpObj, const char* lpszName);

int invokeTool(const QString& qsName);

Remarks

This method is used to invoke a tool from the server. When called, the server will execute the requested tool and the ToolMessages properties will be cleared and populated with a list of response messages associated with the tool.

Name specifies the unique name identifier of the tool that will be invoked.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ListPrompts Method (MCPClient Class)

Retrieves the list of prompts available on the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ListPrompts();

Unicode (Windows)
INT ListPrompts();

int mcpsdk_mcpclient_listprompts(void* lpObj);

int listPrompts();

Remarks

This method is used to request a listing of all of the prompts available on the server. When called, the Prompts properties will be cleared and populated with the retrieved prompts.

This method is typically called during the client's initialization phase or when the client needs to retrieve the latest list of prompts it can request via the GetPrompt method.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ListResources Method (MCPClient Class)

Retrieves the list of resources available on the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ListResources();

Unicode (Windows)
INT ListResources();

int mcpsdk_mcpclient_listresources(void* lpObj);

int listResources();

Remarks

This method is used to request a listing of all of the resources available on the server. When called, the Resources properties will be cleared and populated with the retrieved resources.

This method is typically used during the client's initialization phase, or when the client needs to retrieve the latest list of resources it can request via the ReadResource method.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ListTools Method (MCPClient Class)

Retrieves the list of tools available on the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ListTools();

Unicode (Windows)
INT ListTools();

int mcpsdk_mcpclient_listtools(void* lpObj);

int listTools();

Remarks

This method is used to request a listing of all of the tools available on the server. When called, the Tools properties will be cleared and populated with the retrieved tools.

This method is typically used during the client's initialization phase, or when the client needs to retrieve the latest list of tools it can invoke via the InvokeTool method.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ReadResource Method (MCPClient Class)

Reads a resource from the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ReadResource(const char* lpszUri);

Unicode (Windows)
INT ReadResource(LPCWSTR lpszUri);

int mcpsdk_mcpclient_readresource(void* lpObj, const char* lpszUri);

int readResource(const QString& qsUri);

Remarks

This method is used to request a resource from the server. When called, the ResourceContents properties will be cleared and populated with the data of the requested resource.

Uri specifies the unique identifier for the resource, of which common formats include file:///filename.ext for files, standard HTTP/HTTPS URLs for web resources, or custom schemes like db://table_name.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Error Event (MCPClient Class)

Fires when an error occurs during operation.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(MCPClientErrorEventParams *e);

typedef struct {
  int ConnectionId;
  int ErrorCode;
  const char *Description;
  int reserved;
} MCPClientErrorEventParams;


Unicode (Windows)
virtual INT FireError(MCPClientErrorEventParams *e);

typedef struct {
  INT ConnectionId;
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} MCPClientErrorEventParams;

#define EID_MCPCLIENT_ERROR 1

virtual INT MCPSDK_CALL FireError(INT &iConnectionId, INT &iErrorCode, LPSTR &lpszDescription);

class MCPClientErrorEventParams {
public:
  int connectionId();

  int errorCode();

  const QString &description();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass MCPClient and override this emitter function.
virtual int fireError(MCPClientErrorEventParams *e) {...}
// Or, connect one or more slots to this signal.
void error(MCPClientErrorEventParams *e);

Remarks

This event is fired when an unhandled exception is caught by the class, providing information about the error.

ConnectionId identifies the connection associated with the error.

ErrorCode contains the numeric error code representing the specific error condition.

Description contains a textual description of the error that occurred.

Log Event (MCPClient Class)

This event is fired once for each log message.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireLog(MCPClientLogEventParams *e);

typedef struct {
  int LogLevel;
  const char *Message;
  const char *LogType;
  int reserved;
} MCPClientLogEventParams;


Unicode (Windows)
virtual INT FireLog(MCPClientLogEventParams *e);

typedef struct {
  INT LogLevel;
  LPCWSTR Message;
  LPCWSTR LogType;
  INT reserved;
} MCPClientLogEventParams;

#define EID_MCPCLIENT_LOG 2

virtual INT MCPSDK_CALL FireLog(INT &iLogLevel, LPSTR &lpszMessage, LPSTR &lpszLogType);

class MCPClientLogEventParams {
public:
  int logLevel();

  const QString &message();

  const QString &logType();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass MCPClient and override this emitter function.
virtual int fireLog(MCPClientLogEventParams *e) {...}
// Or, connect one or more slots to this signal.
void log(MCPClientLogEventParams *e);

Remarks

This event fires once for each log message generated by the class. The verbosity is controlled by the LogLevel configuration.

LogLevel indicates the detail level of the message. Possible values are:

Message is the log message.

LogType identifies the type of log entry. Possible values are as follows:

• NFS

SamplingRequest Event (MCPClient Class)

Fires when the server requests language model generation.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireSamplingRequest(MCPClientSamplingRequestEventParams *e);

typedef struct {
  char *ResponseText;
  const char *SystemPrompt;
  int Role;
  char *Model;
  const char *IntelligencePriority;
  const char *SpeedPriority;
  int reserved;
} MCPClientSamplingRequestEventParams;


Unicode (Windows)
virtual INT FireSamplingRequest(MCPClientSamplingRequestEventParams *e);

typedef struct {
  LPWSTR ResponseText;
  LPCWSTR SystemPrompt;
  INT Role;
  LPWSTR Model;
  LPCWSTR IntelligencePriority;
  LPCWSTR SpeedPriority;
  INT reserved;
} MCPClientSamplingRequestEventParams;

#define EID_MCPCLIENT_SAMPLINGREQUEST 3

virtual INT MCPSDK_CALL FireSamplingRequest(LPSTR &lpszResponseText, LPSTR &lpszSystemPrompt, INT &iRole, LPSTR &lpszModel, LPSTR &lpszIntelligencePriority, LPSTR &lpszSpeedPriority);

class MCPClientSamplingRequestEventParams {
public:
  const QString &responseText();
  void setResponseText(const QString &qsResponseText);

  const QString &systemPrompt();

  int role();
  void setRole(int iRole);

  const QString &model();
  void setModel(const QString &qsModel);

  const QString &intelligencePriority();

  const QString &speedPriority();

  int eventRetVal();
  void setEventRetVal(int iRetVal);
};

// To handle, subclass MCPClient and override this emitter function.
virtual int fireSamplingRequest(MCPClientSamplingRequestEventParams *e) {...}
// Or, connect one or more slots to this signal.
void samplingRequest(MCPClientSamplingRequestEventParams *e);

Remarks

When the Transport property is set to ttStdio, this event is fired when the server requests to sample the client's language model. When fired, the messages that make up the server's prompt will be available via the SamplingMessages properties.

To successfully handle the event, a client should construct a prompt from the messages in SamplingMessages and generate a response using the client's language model.

ResponseText should be set to the text output generated by the model when fed the messages in SamplingMessages.

SystemPrompt contains a natural language instruction or directive used to guide the model's behavior during generation. It is typically used to establish context, define tone, or specify how the model should respond.

Role should be set to the role used by the language model when generating ResponseText. Valid roles include:

Model should be set to the name of the model used to generate ResponseText.

IntelligencePriority specifies how much the client should prioritize advanced capabilities when generating ResponseText. Its value is a decimal number ranging from 0.0 to 1.0. Higher values prefer more capable models.

SpeedPriority specifies how much the client should prioritize low latency when generating ResponseText. Its value is a decimal number ranging from 0.0 to 1.0. Higher values prefer faster models.

Prompt Type

A registered prompt.

Syntax

MCPSDKPrompt (declared in mcpsdk.h)

Remarks

This type represents a registered prompt that can be requested by the client.

• Description
• Name

Fields

Constructors

Prompt()

PromptMessage Type

A prompt message.

Syntax

MCPSDKPromptMessage (declared in mcpsdk.h)

Remarks

This type represents an individual message within a prompt that can be requested by the client.

• Role
• Text

Fields

Constructors

PromptMessage()

PromptMessage(int iRole, const char* lpszText)

Resource Type

A registered resource.

Syntax

MCPSDKResource (declared in mcpsdk.h)

Remarks

This type represents a registered resource that can be requested by the client.

• Description
• Mimetype
• Name
• Size
• Uri

Fields

Constructors

Resource()

ResourceContent Type

A resource's content.

Syntax

MCPSDKResourceContent (declared in mcpsdk.h)

Remarks

This type represents the content for an individual resource that can be requested by the client.

• Data
• MimeType
• Uri

Fields

Constructors

ResourceContent()

SamplingMessage Type

An individual message in a sampling request.

Syntax

MCPSDKSamplingMessage (declared in mcpsdk.h)

Remarks

This type represents an individual message within a sampling request received by the server.

• Role
• Text

Fields

Constructors

SamplingMessage()

Tool Type

A registered tool.

Syntax

MCPSDKTool (declared in mcpsdk.h)

Remarks

This type represents a registered tool that can be requested by the client.

• Description
• Name

Fields

Constructors

Tool()

ToolMessage Type

A tool message.

Syntax

MCPSDKToolMessage (declared in mcpsdk.h)

Remarks

This type represents an individual message within a tool response.

• MessageType
• Value

Fields

Constructors

ToolMessage()

MCPSDKList Type

Syntax

MCPSDKList<T> (declared in mcpsdk.h)

Remarks

MCPSDKList is a generic class that is used to hold a collection of objects of type T, where T is one of the custom types supported by the MCPClient class.

int GetCount() {}

int SetCount(int count) {}

T* Get(int index) {}

T* Set(int index, T* value) {}

Config Settings (MCPClient Class)

MCPClient Config Settings

Base Config Settings

Trappable Errors (MCPClient Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

MCPClient Errors