Module io.modelcontextprotocol.sdk.mcp

Package io.modelcontextprotocol.server

Class McpAsyncServerExchange

java.lang.Object

io.modelcontextprotocol.server.McpAsyncServerExchange

public class McpAsyncServerExchange
extends Object

Represents an asynchronous exchange with a Model Context Protocol (MCP) client. The exchange provides methods to interact with the client and query its capabilities.

Author:

Dariusz Jędrzejczyk

Constructor Summary

Constructors

Constructor	Description
McpAsyncServerExchange(McpServerSession session, McpSchema.ClientCapabilities clientCapabilities, McpSchema.Implementation clientInfo)	Create a new asynchronous exchange with the client.

Method Summary

Modifier and Type	Method	Description
reactor.core.publisher.Mono<McpSchema.CreateMessageResult>	createMessage(McpSchema.CreateMessageRequest createMessageRequest)	Create a new message using the sampling capabilities of the client.
McpSchema.ClientCapabilities	getClientCapabilities()	Get the client capabilities that define the supported features and functionality.
McpSchema.Implementation	getClientInfo()	Get the client implementation information.
reactor.core.publisher.Mono<McpSchema.ListRootsResult>	listRoots()	Retrieves the list of all roots provided by the client.
reactor.core.publisher.Mono<McpSchema.ListRootsResult>	listRoots(String cursor)	Retrieves a paginated list of roots provided by the client.

Methods inherited from class java.lang.Object

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

Constructor Details

McpAsyncServerExchange

public McpAsyncServerExchange(McpServerSession session,
 McpSchema.ClientCapabilities clientCapabilities,
 McpSchema.Implementation clientInfo)

Create a new asynchronous exchange with the client.

Parameters:

session - The server session representing a 1-1 interaction.

clientCapabilities - The client capabilities that define the supported features and functionality.

clientInfo - The client implementation information.

Method Details

getClientCapabilities

public McpSchema.ClientCapabilities getClientCapabilities()

Get the client capabilities that define the supported features and functionality.

Returns:

The client capabilities

getClientInfo

public McpSchema.Implementation getClientInfo()

Get the client implementation information.

Returns:

The client implementation details

createMessage

public reactor.core.publisher.Mono<McpSchema.CreateMessageResult> createMessage(McpSchema.CreateMessageRequest createMessageRequest)

Create a new message using the sampling capabilities of the client. The Model Context Protocol (MCP) provides a standardized way for servers to request LLM sampling (“completions” or “generations”) from language models via clients. This flow allows clients to maintain control over model access, selection, and permissions while enabling servers to leverage AI capabilities—with no server API keys necessary. Servers can request text or image-based interactions and optionally include context from MCP servers in their prompts.

Parameters:

createMessageRequest - The request to create a new message

Returns:

A Mono that completes when the message has been created

See Also:

• McpSchema.CreateMessageRequest
• McpSchema.CreateMessageResult
• Sampling Specification

listRoots

public reactor.core.publisher.Mono<McpSchema.ListRootsResult> listRoots()

Retrieves the list of all roots provided by the client.

Returns:

A Mono that emits the list of roots result.

listRoots

public reactor.core.publisher.Mono<McpSchema.ListRootsResult> listRoots(String cursor)

Retrieves a paginated list of roots provided by the client.

Parameters:

cursor - Optional pagination cursor from a previous list request

Returns:

A Mono that emits the list of roots result containing