Method handleAutomaticTaskPolling

src/server/mcp.ts:363–398

* Handles automatic task polling for tools with taskSupport 'optional'.

(
        tool: RegisteredTool,
        request: RequestT,
        extra: RequestHandlerExtra<ServerRequest, ServerNotification>
    )

     * Handles automatic task polling for tools with taskSupport 'optional'.
     */
    private async handleAutomaticTaskPolling<RequestT extends CallToolRequest>(
        tool: RegisteredTool,
        request: RequestT,
        extra: RequestHandlerExtra<ServerRequest, ServerNotification>
    ): Promise<CallToolResult> {
        if (!extra.taskStore) {
            throw new Error('No task store provided for task-capable tool.');
        }

        // Validate input and create task
        const args = await this.validateToolInput(tool, request.params.arguments, request.params.name);
        const handler = tool.handler as ToolTaskHandler<ZodRawShapeCompat | undefined>;
        const taskExtra = { ...extra, taskStore: extra.taskStore };

        const createTaskResult: CreateTaskResult = args // undefined only if tool.inputSchema is undefined
            ? await Promise.resolve((handler as ToolTaskHandler<ZodRawShapeCompat>).createTask(args, taskExtra))
            : // eslint-disable-next-line @typescript-eslint/no-explicit-any
              await Promise.resolve(((handler as ToolTaskHandler<undefined>).createTask as any)(taskExtra));

        // Poll until completion
        const taskId = createTaskResult.task.taskId;
        let task = createTaskResult.task;
        const pollInterval = task.pollInterval ?? 5000;

        while (task.status !== 'completed' && task.status !== 'failed' && task.status !== 'cancelled') {
            await new Promise(resolve => setTimeout(resolve, pollInterval));
            const updatedTask = await extra.taskStore.getTask(taskId);
            if (!updatedTask) {
                throw new McpError(ErrorCode.InternalError, `Task ${taskId} not found during polling`);
            }
            task = updatedTask;
        }

        // Return the final result
        return (await extra.taskStore.getTaskResult(taskId)) as CallToolResult;
    }

    private _completionHandlerInitialized = false;