MCP Client class for connecting to MCP servers. More...

#include <McpClient.qc.dox.h>

Public Member Methods
void	destructor ()
	Destructor - closes the connection.

string	getUrl ()
	Returns the server URL.

bool	isInitialized ()
	Checks if the client is initialized.

soft< string >	getProtocolVersion ()
	Gets the negotiated protocol version.

soft< hash< auto > >	getServerInfo ()
	Gets server information.

soft< hash< auto > >	getServerCapabilities ()
	Gets server capabilities.

bool	ping ()
	Sends a ping request to check server health.

list< auto >	listTools ()
	Lists available tools from the server.

list< auto >	listResources ()
	Lists available resources from the server.

hash< auto >	readResource (string uri)
	Reads a resource from the server.

list< auto >	listPrompts ()
	Lists available prompts from the server.

hash< auto >	getPrompt (string name, soft< hash< auto > > arguments)
	Gets a prompt from the server.

hash< auto >	complete (hash< auto > ref, hash< auto > argument)
	Requests completion suggestions.

void	setLogLevel (string level)
	Sets the server log level.

void	setCallback (string event, code callback)
	Registers an event callback.

void	removeCallback (string event)
	Removes an event callback.

void	startSseListener ()
	Starts the SSE listener for server notifications.

void	stopSseListener ()
	Stops the SSE listener.

bool	isSseListenerRunning ()
	Checks if SSE listener is running.

void	startLegacySseListener ()
	Starts the legacy SSE listener.

void	stopLegacySseListener ()
	Stops the legacy SSE listener.

bool	startStreamableListener ()
	Starts the streamable HTTP GET listener.

void	stopStreamableListener ()
	Stops the streamable HTTP GET listener.

soft< HttpStreamClient::HTTPResponseStream >	openStreamableGet ()
	Opens a streamable HTTP GET event stream.

void	streamableEventLoop ()
	Streamable GET event loop.

void	close ()
	Closes the MCP connection.

soft< string >	getSessionId ()
	Gets the session ID.

void	setSessionId (string sid)
	Sets the session ID (used internally)

void	ensureInitialized ()
	Internal: Ensures the client is initialized.

int	getNextRequestId ()
	Internal: Gets the next request ID.

hash< auto >	sendRequest (string method, soft< hash< auto > > params)
	Internal: Sends a JSON-RPC request with streamable HTTP, falling back to legacy.

hash< auto >	sendRequestLegacy (string method, soft< hash< auto > > params)
	Internal: Sends a JSON-RPC request using legacy HTTP transport.

hash< auto >	sendRequestStreamable (string method, soft< hash< auto > > params)
	Internal: Sends a JSON-RPC request using streamable HTTP.

hash< auto >	readStreamableJsonResponse (HttpStreamClient::HTTPResponseStream stream)
	Internal: Reads a streamable JSON response.

hash< auto >	readStreamableSseResponse (HttpStreamClient::HTTPResponseStream stream, int request_id)
	Internal: Reads a streamable SSE response and returns the matching response.

soft< hash< auto > >	handleStreamableMessage (auto msg, int request_id)
	Internal: Handles parsed streamable message payloads.

string	readStreamableBody (HttpStreamClient::HTTPResponseStream stream)
	Internal: Reads remaining stream body into a string.

void	sendNotification (string method, soft< hash< auto > > params)
	Internal: Sends a JSON-RPC notification (no response expected)

void	invokeCallback (string event, soft< list< auto > > args)
	Internal: Invokes an event callback.

void	handleSseConnected ()
	Internal: Handles SSE connection events.

void	handleSseClosed ()
	Internal: Handles SSE disconnection events.

void	update (string event_id, hash< auto > data_)
	Observer callback for SSE client events.

void	handleNotification (hash< auto > message)
	Internal: Handles a server notification.

void	logDebug (string fmt)
	Internal: Logs a debug message.

Public Attributes
const auto	DefaultConnectTimeout = ...
	Default connection timeout (30 seconds)

const auto	DefaultTimeout = ...
	Default request timeout (60 seconds)

const auto	JsonRpcVersion = ...
	JSON-RPC version.

Private Attributes
string	url
	The server URL.

HTTPClient	http
	HTTP client for requests.

HTTPClient	stream_http
	HTTP client for streamable GET listener.

soft< string >	session_id
	MCP session ID.

soft< string >	protocol_version
	Negotiated protocol version.

soft< hash< auto > >	server_info
	Server info after initialization.

soft< hash< auto > >	server_capabilities
	Server capabilities.

soft< LoggerInterface >	logger
	Logger interface.

hash< string, code >	callbacks
	Event callbacks.

soft< ServerSentEventClient::ServerSentEventClient >	sse_client
	SSE client for receiving server messages.

ThreadPool	stream_tp
	Streamable GET listener thread pool.

soft< HttpStreamClient::HTTPResponseStream >	streamable_stream
	Streamable GET response stream.

hash< string, hash< auto > >	pending_requests
	Pending requests waiting for responses.

Detailed Description

MCP Client class for connecting to MCP servers.

This class provides a client implementation for the Model Context Protocol (MCP). It allows connecting to MCP servers over HTTP with JSON-RPC 2.0 protocol.

Example:: McpClient client("http://localhost:8080/mcp");

# Initialize connection

hash<auto> info = client.initialize({

"name": "MyApp",

"version": "1.0",

});

# Call a tool

hash<auto> result = client.callTool("echo", {"message": "Hello"});

client.close();

McpClient
the McpClient namespace holds all public definitions in the McpClient module
Definition McpClient.qc.dox.h:2

Member Function Documentation

◆ complete()

hash< auto > McpClient::McpClient::complete	(	hash< auto >	ref,
		hash< auto >	argument
	)

Requests completion suggestions.

Parameters

ref	the reference (prompt or resource) to complete for
argument	the argument being completed

Returns: completion suggestions

Exceptions

MCP-ERROR if the request fails

◆ getPrompt()

hash< auto > McpClient::McpClient::getPrompt	(	string	name,
		soft< hash< auto > >	arguments
	)

Gets a prompt from the server.

Parameters

name	the name of the prompt
arguments	optional arguments for the prompt

Returns: the prompt with messages

Exceptions

MCP-ERROR if the request fails

◆ getProtocolVersion()

soft< string > McpClient::McpClient::getProtocolVersion ( )

Gets the negotiated protocol version.

Returns: the protocol version string or NOTHING if not initialized

◆ getServerCapabilities()

soft< hash< auto > > McpClient::McpClient::getServerCapabilities ( )

Gets server capabilities.

Returns: server capabilities hash or NOTHING if not initialized

◆ getServerInfo()

soft< hash< auto > > McpClient::McpClient::getServerInfo ( )

Gets server information.

Returns: server info hash or NOTHING if not initialized

◆ getSessionId()

soft< string > McpClient::McpClient::getSessionId ( )

Gets the session ID.

Returns: the MCP session ID or NOTHING if not set

◆ isInitialized()

bool McpClient::McpClient::isInitialized ( )

Checks if the client is initialized.

Returns: True if initialized, False otherwise

◆ isSseListenerRunning()

bool McpClient::McpClient::isSseListenerRunning ( )

Checks if SSE listener is running.

Returns: True if SSE listener is active

◆ listPrompts()

list< auto > McpClient::McpClient::listPrompts ( )

Lists available prompts from the server.

Returns: list of prompt information

Exceptions

MCP-ERROR if the request fails

◆ listResources()

list< auto > McpClient::McpClient::listResources ( )

Lists available resources from the server.

Returns: list of resource information

Exceptions

MCP-ERROR if the request fails

◆ listTools()

list< auto > McpClient::McpClient::listTools ( )

Lists available tools from the server.

Returns: list of tool information

Exceptions

MCP-ERROR if the request fails

◆ ping()

bool McpClient::McpClient::ping ( )

Sends a ping request to check server health.

Returns: True if server responds successfully

Exceptions

MCP-PING-ERROR if ping fails

◆ readResource()

hash< auto > McpClient::McpClient::readResource ( string uri )

Reads a resource from the server.

Parameters

uri	the URI of the resource to read

Returns: the resource content

Exceptions

MCP-ERROR if the request fails

◆ removeCallback()

void McpClient::McpClient::removeCallback ( string event )

Removes an event callback.

Parameters

event the event name to remove

◆ setCallback()

void McpClient::McpClient::setCallback	(	string	event,
		code	callback
	)

Registers an event callback.

Parameters

event	the event name (onToolsChanged, onResourcesChanged, onPromptsChanged, onLogMessage, onError)
callback	the callback code to invoke

Supported events:

onToolsChanged: called when the server's tool list changes
onResourcesChanged: called when the server's resource list changes
onPromptsChanged: called when the server's prompt list changes
onLogMessage: called when the server sends a log message (receives: string level, *auto data, *string logger)
onError: called when an error occurs (receives: string error_message)
onConnected: called when SSE connection is established
onDisconnected: called when SSE connection is closed

◆ setLogLevel()

void McpClient::McpClient::setLogLevel ( string level )

Sets the server log level.

Parameters

level the log level to set

Exceptions

MCP-ERROR	if the request fails
MCP-INVALID-LOG-LEVEL	if the level is not valid

◆ startSseListener()

void McpClient::McpClient::startSseListener ( )

Starts the SSE listener for server notifications.

This starts a background thread that listens for Server-Sent Events from the MCP server. Call this after initialize() to receive notifications.

Exceptions

MCP-NOT-INITIALIZED if client is not initialized

The documentation for this class was generated from the following file:

doxygen/qlib/McpClient/McpClient.qc.dox.h

Public Member Methods

Public Attributes

Private Attributes

Detailed Description

Member Function Documentation

◆ complete()

◆ getPrompt()

◆ getProtocolVersion()

◆ getServerCapabilities()

◆ getServerInfo()

◆ getSessionId()

◆ isInitialized()

◆ isSseListenerRunning()

◆ listPrompts()

◆ listResources()

◆ listTools()

◆ ping()

◆ readResource()

◆ removeCallback()

◆ setCallback()

◆ setLogLevel()

◆ startSseListener()