Interface McpClientListener

public interface McpClientListener
Listener interface for monitoring MCP client operations.

  • Method Details

    • beforeInitialize

      default void beforeInitialize(McpCallContext context)
      Called before sending the initialize request to the MCP server. Legacy protocol only (up to 2025-11-25).

    • afterInitialize

      default void afterInitialize(McpCallContext context)
      Called after the initialize request completes successfully. Legacy protocol only (up to 2025-11-25).

    • onInitializeError

      default void onInitializeError(McpCallContext context, Throwable error)
      Called when the initialize request fails. Legacy protocol only (up to 2025-11-25).

    • beforeServerDiscover

      default void beforeServerDiscover(McpCallContext context)
      Called before sending the server/discover request to the MCP server. Only used with MCP protocol 2026-07-28 and later.

    • afterServerDiscover

      default void afterServerDiscover(McpCallContext context, McpDiscoverResult result)
      Called after a successful server/discover request. Only used with MCP protocol 2026-07-28 and later.

    • onServerDiscoverError

      default void onServerDiscoverError(McpCallContext context, Throwable error)
      Called when the server/discover request fails. Only used with MCP protocol 2026-07-28 and later.

    • beforeExecuteTool

      default void beforeExecuteTool(McpCallContext context)
      Called before executing a tool.

    • afterExecuteTool

      default void afterExecuteTool(McpCallContext context, ToolExecutionResult result, Map<String,Object> rawResult)
      Called after executing a tool if the execution was successful, or if it resulted in an application-level error (but not a protocol-level or communication error).

    • onExecuteToolError

      default void onExecuteToolError(McpCallContext context, Throwable error)
      Called when a tool execution fails due to a protocol-level or communication error.

    • beforeToolsList

      default void beforeToolsList(McpCallContext context)
      Called before listing tools from the MCP server.

    • afterToolsList

      default void afterToolsList(McpCallContext context, List<ToolSpecification> tools)
      Called after listing tools from the MCP server completes successfully.

    • onToolsListError

      default void onToolsListError(McpCallContext context, Throwable error)
      Called when listing tools from the MCP server fails.

    • beforeResourceGet

      default void beforeResourceGet(McpCallContext context)
      Called before getting a resource.

    • afterResourceGet

      default void afterResourceGet(McpCallContext context, McpReadResourceResult result, Map<String,Object> rawResult)
      Called after getting a resource.

    • onResourceGetError

      default void onResourceGetError(McpCallContext context, Throwable error)
      Called when getting a resource fails.

    • beforeResourcesList

      default void beforeResourcesList(McpCallContext context)
      Called before listing resources from the MCP server.

    • afterResourcesList

      default void afterResourcesList(McpCallContext context, List<McpResource> resources)
      Called after listing resources from the MCP server completes successfully.

    • onResourcesListError

      default void onResourcesListError(McpCallContext context, Throwable error)
      Called when listing resources from the MCP server fails.

    • beforeResourceTemplatesList

      default void beforeResourceTemplatesList(McpCallContext context)
      Called before listing resource templates from the MCP server.

    • afterResourceTemplatesList

      default void afterResourceTemplatesList(McpCallContext context, List<McpResourceTemplate> templates)
      Called after listing resource templates from the MCP server completes successfully.

    • onResourceTemplatesListError

      default void onResourceTemplatesListError(McpCallContext context, Throwable error)
      Called when listing resource templates from the MCP server fails.

    • beforeResourceSubscribe

      default void beforeResourceSubscribe(McpCallContext context)
      Called before subscribing to a resource. Legacy protocol only (up to 2025-11-25).

    • afterResourceSubscribe

      default void afterResourceSubscribe(McpCallContext context)
      Called after subscribing to a resource completes successfully. Legacy protocol only (up to 2025-11-25).

    • onResourceSubscribeError

      default void onResourceSubscribeError(McpCallContext context, Throwable error)
      Called when subscribing to a resource fails. Legacy protocol only (up to 2025-11-25).

    • beforeResourceUnsubscribe

      default void beforeResourceUnsubscribe(McpCallContext context)
      Called before unsubscribing from a resource. Legacy protocol only (up to 2025-11-25).

    • afterResourceUnsubscribe

      default void afterResourceUnsubscribe(McpCallContext context)
      Called after unsubscribing from a resource completes successfully. Legacy protocol only (up to 2025-11-25).

    • onResourceUnsubscribeError

      default void onResourceUnsubscribeError(McpCallContext context, Throwable error)
      Called when unsubscribing from a resource fails. Legacy protocol only (up to 2025-11-25).

    • beforeResourcesSubscribe

      default void beforeResourcesSubscribe(McpCallContext context, List<String> uris)
      Called before subscribing to resources via the modern subscriptions/listen mechanism. Only used with MCP protocol 2026-07-28 and later.

    • afterResourcesSubscribe

      default void afterResourcesSubscribe(McpCallContext context, long subscriptionId, List<String> uris)
      Called after subscribing to resources completes successfully. Only used with MCP protocol 2026-07-28 and later.
      Parameters:
      subscriptionId - the subscription ID (the JSON-RPC request ID of the subscriptions/listen call)

    • onResourcesSubscribeError

      default void onResourcesSubscribeError(McpCallContext context, Throwable error)
      Called when subscribing to resources fails, either because the server rejected the subscriptions/listen request or because it never acknowledged it in time. Only used with MCP protocol 2026-07-28 and later.

    • beforeResourcesUnsubscribe

      default void beforeResourcesUnsubscribe(@Nullable McpCallContext context, long subscriptionId)
      Called before unsubscribing from resources via subscription ID. Only used with MCP protocol 2026-07-28 and later.
      Parameters:
      context - the call context wrapping the notifications/cancelled message, or null for transports that cancel by closing the SSE stream (e.g. Streamable HTTP)

    • afterResourcesUnsubscribe

      default void afterResourcesUnsubscribe(@Nullable McpCallContext context, long subscriptionId)
      Called after unsubscribing from resources completes. Only used with MCP protocol 2026-07-28 and later.
      Parameters:
      context - the call context wrapping the notifications/cancelled message, or null for transports that cancel by closing the SSE stream (e.g. Streamable HTTP)

    • beforePromptGet

      default void beforePromptGet(McpCallContext context)
      Called before getting a prompt.

    • afterPromptGet

      default void afterPromptGet(McpCallContext context, McpGetPromptResult result, Map<String,Object> rawResult)
      Called after getting a prompt.

    • onPromptGetError

      default void onPromptGetError(McpCallContext context, Throwable error)
      Called when getting a prompt fails.

    • beforePromptsList

      default void beforePromptsList(McpCallContext context)
      Called before listing prompts from the MCP server.

    • afterPromptsList

      default void afterPromptsList(McpCallContext context, List<McpPrompt> prompts)
      Called after listing prompts from the MCP server completes successfully.

    • onPromptsListError

      default void onPromptsListError(McpCallContext context, Throwable error)
      Called when listing prompts from the MCP server fails.

    • beforePing

      default void beforePing(McpCallContext context)
      Called before sending a ping request to the MCP server.

    • afterPing

      default void afterPing(McpCallContext context)
      Called after the ping request completes successfully (the server has responded with a pong).

    • onPingError

      default void onPingError(McpCallContext context, Throwable error)
      Called when the ping request fails (the server didn't send a pong in time or some transport-level issue occurred).

    • onRootsListChanged

      default void onRootsListChanged(McpCallContext context)
      Called after the client sends a notifications/roots/list_changed notification to the server.

    • onNotificationToolsListChanged

      default void onNotificationToolsListChanged()
      Called when the server sends a notifications/tools/list_changed notification.

    • onNotificationResourcesListChanged

      default void onNotificationResourcesListChanged()
      Called when the server sends a notifications/resources/list_changed notification.

    • onNotificationPromptsListChanged

      default void onNotificationPromptsListChanged()
      Called when the server sends a notifications/prompts/list_changed notification.

    • onNotificationResourceUpdated

      default void onNotificationResourceUpdated(String uri)
      Called when the server sends a notifications/resources/updated notification.

    • onNotificationMessage

      default void onNotificationMessage(McpLogMessage message)
      Called when the server sends a notifications/message (log message) notification.

    • onNotificationProgress

      default void onNotificationProgress(McpProgressNotification notification)
      Called when the server sends a notifications/progress notification.

    • onNotificationCancelled

      default void onNotificationCancelled(long requestId, String reason)
      Called when the server sends a notifications/cancelled notification to abort a previously accepted request. The corresponding pending operation, if any, is completed exceptionally before this listener is invoked.
      Parameters:
      requestId - the id of the cancelled request, as supplied by the server
      reason - an optional server-supplied reason for the cancellation; may be null

    • onServerPing

      default void onServerPing()
      Called when the server sends a ping request and the client responds.

    • onServerRootsList

      default void onServerRootsList()
      Called when the server sends a roots/list request and the client responds.