Langfuse MCP Server

import { z } from 'zod'; import { LangfuseAnalyticsClient } from '../langfuse-client.js'; import { ServiceUsage } from '../types.js'; export const usageByServiceSchema = z.object({ from: z.string().datetime(), to: z.string().datetime(), serviceTagKey: z.string().default('service'), environment: z.string().optional(), limit: z.number().optional().default(20), }); export async function usageByService( client: LangfuseAnalyticsClient, args: z.infer<typeof usageByServiceSchema> ) { const filters: any[] = []; if (args.environment) { filters.push({ column: 'environment', operator: 'equals', value: args.environment, type: 'string', }); } const response = await client.getMetrics({ view: 'traces', from: args.from, to: args.to, metrics: [ { measure: 'totalCost', aggregation: 'sum' }, { measure: 'totalTokens', aggregation: 'sum' }, { measure: 'count', aggregation: 'count' }, ], dimensions: [{ field: 'tags' }], filters, }); // Post-process to extract service from tags const serviceMap = new Map<string, ServiceUsage>(); if (response.data && Array.isArray(response.data)) { response.data.forEach((row: any) => { const tags = Array.isArray(row.tags) ? row.tags : []; // Find service tag const serviceTag = tags.find((tag: string) => typeof tag === 'string' && tag.startsWith(`${args.serviceTagKey}:`) ); if (serviceTag) { const service = serviceTag.split(':')[1]; const existing = serviceMap.get(service) || { service, totalCost: 0, totalTokens: 0, traceCount: 0, }; serviceMap.set(service, { service, totalCost: existing.totalCost + (row.totalCost_sum || 0), totalTokens: existing.totalTokens + (row.totalTokens_sum || 0), traceCount: existing.traceCount + (row.count_count || 0), }); } }); } const serviceUsages = Array.from(serviceMap.values()) .sort((a, b) => b.totalCost - a.totalCost) .slice(0, args.limit); return { content: [ { type: 'text' as const, text: JSON.stringify( { projectId: client.getProjectId(), from: args.from, to: args.to, serviceTagKey: args.serviceTagKey, services: serviceUsages, }, null, 2 ), }, ], }; }