import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import type { ReadResourceResult } from '@modelcontextprotocol/sdk/types.js';
import { getServerWithInternals } from '../mcp/server-internals.js';
import { logger } from '../utils/logger.js';
/**
* Dynamic status resource that changes over time.
* Demonstrates resource subscriptions and update notifications.
*/
// Server status state
const serverStatus = {
status: 'running' as 'running' | 'idle' | 'busy',
uptime: 0,
requestCount: 0,
lastUpdated: new Date().toISOString(),
};
// Track update interval
let statusUpdateInterval: NodeJS.Timeout | null = null;
/**
* Start status updates (for demonstration).
* In production, this would track real server metrics.
*/
export function startStatusUpdates(server: McpServer): void {
if (statusUpdateInterval) {
return; // Already running
}
// Update status every 10 seconds
statusUpdateInterval = setInterval(() => {
// Simulate status changes
serverStatus.uptime += 10;
serverStatus.requestCount += Math.floor(Math.random() * 5);
const statuses: Array<'running' | 'idle' | 'busy'> = ['running', 'idle', 'busy'];
serverStatus.status = statuses[Math.floor(Math.random() * 3)];
serverStatus.lastUpdated = new Date().toISOString();
// Notify subscribers of the update
try {
getServerWithInternals(server).sendResourceUpdated?.({
uri: 'status://server',
});
logger.debug('status_resource', {
message: 'Status updated, notification sent',
status: serverStatus.status,
uptime: serverStatus.uptime,
});
} catch (error) {
logger.error('status_resource', {
message: 'Failed to send resource update notification',
error: (error as Error).message,
});
}
}, 10_000);
logger.info('status_resource', {
message: 'Status update notifications started (every 10s)',
});
}
/**
* Stop status updates.
*/
export function stopStatusUpdates(): void {
if (statusUpdateInterval) {
clearInterval(statusUpdateInterval);
statusUpdateInterval = null;
logger.info('status_resource', {
message: 'Status update notifications stopped',
});
}
}
/**
* Increment request count (call this from request handlers to track real metrics).
*/
export function incrementRequestCount(): void {
serverStatus.requestCount++;
serverStatus.lastUpdated = new Date().toISOString();
}
/**
* Status resource handler.
*/
export const statusResource = {
uri: 'status://server',
name: 'Server Status',
description:
'Dynamic server status (subscribable resource with update notifications)',
mimeType: 'application/json',
handler: async (): Promise<ReadResourceResult> => {
logger.debug('status_resource', { message: 'Server status requested' });
const statusData = {
...serverStatus,
timestamp: new Date().toISOString(),
};
return {
contents: [
{
uri: 'status://server',
mimeType: 'application/json',
text: JSON.stringify(statusData, null, 2),
},
],
};
},
};
