The Graph Token API MCP

import promClient from 'prom-client'; // Create a registry for our metrics export const register = new promClient.Registry(); // Tool calls counter metric export const toolCallsCounter = new promClient.Counter({ name: 'tokenapi_mcp_tool_calls_total', help: 'Total number of MCP tool calls', labelNames: ['tool_name', 'status'] as const, registers: [register] }); // Tool call duration histogram metric export const toolCallDurationHistogram = new promClient.Histogram({ name: 'tokenapi_mcp_tool_call_duration_seconds', help: 'Duration of MCP tool calls in seconds', labelNames: ['tool_name'] as const, buckets: [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0], registers: [register] }); // Helper function to track tool execution export async function trackToolExecution<T>( toolName: string, execution: () => Promise<T> ): Promise<T> { const endTimer = toolCallDurationHistogram.startTimer({ tool_name: toolName }); try { const result = await execution(); // Record successful execution toolCallsCounter.inc({ tool_name: toolName, status: 'success' }); endTimer(); return result; } catch (error) { // Record failed execution toolCallsCounter.inc({ tool_name: toolName, status: 'error' }); endTimer(); throw error; } } // Export metrics endpoint handler export async function getMetrics(): Promise<string> { return await register.metrics(); } // Start metrics server using Bun export function startMetricsServer(hostname: string = "0.0.0.0", port: number = 9090) { const server = Bun.serve({ hostname, port, async fetch(req) { const url = new URL(req.url); if (url.pathname === '/metrics') { return new Response(await getMetrics(), { headers: { 'Content-Type': 'text/plain; version=0.0.4; charset=utf-8', }, }); } if (url.pathname === '/health') { return new Response('OK', { status: 200 }); } return new Response('Not Found', { status: 404 }); }, }); console.log(`Metrics server running on http://localhost:${port}/metrics`); return server; }