Module io.modelcontextprotocol.sdk.mcp

Package io.modelcontextprotocol.spec

Class McpServerSession

java.lang.Object

io.modelcontextprotocol.spec.McpServerSession

All Implemented Interfaces:

McpSession

public class McpServerSession
extends Object
implements McpSession

Represents a Model Control Protocol (MCP) session on the server side. It manages bidirectional JSON-RPC communication with the client.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	McpServerSession.Factory	Factory for creating server sessions which delegate to a provided 1:1 transport with a connected client.
static interface	McpServerSession.InitNotificationHandler	Notification handler for the initialization notification from the client.
static interface	McpServerSession.InitRequestHandler	Request handler for the initialization request.
static interface	McpServerSession.NotificationHandler	A handler for client-initiated notifications.
static interface	McpServerSession.RequestHandler<T>	A handler for client-initiated requests.

Constructor Summary

Constructors

Constructor	Description
McpServerSession(String id, Duration requestTimeout, McpServerTransport transport, McpServerSession.InitRequestHandler initHandler, McpServerSession.InitNotificationHandler initNotificationHandler, Map<String,McpServerSession.RequestHandler<?>> requestHandlers, Map<String,McpServerSession.NotificationHandler> notificationHandlers)	Creates a new server session with the given parameters and the transport to use.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the session and releases any associated resources.
reactor.core.publisher.Mono<Void>	closeGracefully()	Closes the session and releases any associated resources asynchronously.
String	getId()	Retrieve the session id.
reactor.core.publisher.Mono<Void>	handle(McpSchema.JSONRPCMessage message)	Called by the McpServerTransportProvider once the session is determined.
void	init(McpSchema.ClientCapabilities clientCapabilities, McpSchema.Implementation clientInfo)	Called upon successful initialization sequence between the client and the server with the client capabilities and information.
reactor.core.publisher.Mono<Void>	sendNotification(String method, Object params)	Sends a notification to the model client or server with parameters.
<T> reactor.core.publisher.Mono<T>	sendRequest(String method, Object requestParams, com.fasterxml.jackson.core.type.TypeReference<T> typeRef)	Sends a request to the model counterparty and expects a response of type T.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.modelcontextprotocol.spec.McpSession

sendNotification

Constructor Details

McpServerSession

public McpServerSession(String id,
 Duration requestTimeout,
 McpServerTransport transport,
 McpServerSession.InitRequestHandler initHandler,
 McpServerSession.InitNotificationHandler initNotificationHandler,
 Map<String,McpServerSession.RequestHandler<?>> requestHandlers,
 Map<String,McpServerSession.NotificationHandler> notificationHandlers)

Creates a new server session with the given parameters and the transport to use.

Parameters:

id - session id

transport - the transport to use

initHandler - called when a McpSchema.InitializeRequest is received by the server

initNotificationHandler - called when a McpSchema.METHOD_NOTIFICATION_INITIALIZED is received.

requestHandlers - map of request handlers to use

notificationHandlers - map of notification handlers to use

Method Details

getId

public String getId()

Retrieve the session id.

Returns:

session id

init

public void init(McpSchema.ClientCapabilities clientCapabilities,
 McpSchema.Implementation clientInfo)

Called upon successful initialization sequence between the client and the server with the client capabilities and information. Initialization Spec

Parameters:

clientCapabilities - the capabilities the connected client provides

clientInfo - the information about the connected client

sendRequest

public <T> reactor.core.publisher.Mono<T> sendRequest(String method,
 Object requestParams,
 com.fasterxml.jackson.core.type.TypeReference<T> typeRef)

Description copied from interface: McpSession

Sends a request to the model counterparty and expects a response of type T.

This method handles the request-response pattern where a response is expected from the client or server. The response type is determined by the provided TypeReference.

Specified by:

sendRequest in interface McpSession

Type Parameters:

T - the type of the expected response

Parameters:

method - the name of the method to be called on the counterparty

requestParams - the parameters to be sent with the request

typeRef - the TypeReference describing the expected response type

Returns:

a Mono that will emit the response when received

sendNotification

public reactor.core.publisher.Mono<Void> sendNotification(String method,
 Object params)

Description copied from interface: McpSession

Sends a notification to the model client or server with parameters.

Similar to McpSession.sendNotification(String) but allows sending additional parameters with the notification.

Specified by:

sendNotification in interface McpSession

Parameters:

method - the name of the notification method to be sent to the counterparty

params - parameters to be sent with the notification

Returns:

a Mono that completes when the notification has been sent

handle

public reactor.core.publisher.Mono<Void> handle(McpSchema.JSONRPCMessage message)

Called by the McpServerTransportProvider once the session is determined. The purpose of this method is to dispatch the message to an appropriate handler as specified by the MCP server implementation (McpAsyncServer or McpSyncServer) via McpServerSession.Factory that the server creates.

Parameters:

message - the incoming JSON-RPC message

Returns:

a Mono that completes when the message is processed

closeGracefully

public reactor.core.publisher.Mono<Void> closeGracefully()

Description copied from interface: McpSession

Closes the session and releases any associated resources asynchronously.

Specified by:

closeGracefully in interface McpSession

Returns:

a reactor.core.publisher.Mono<Void> that completes when the session has been closed.

close

public void close()

Description copied from interface: McpSession

Closes the session and releases any associated resources.

Specified by:

close in interface McpSession