Langfuse MCP Server

import { z } from 'zod'; import { LangfuseAnalyticsClient } from '../langfuse-client.js'; import { ExpensiveTrace } from '../types.js'; export const topExpensiveTracesSchema = z.object({ from: z.string().datetime(), to: z.string().datetime(), limit: z.number().optional().default(10), environment: z.string().optional(), }); export async function topExpensiveTraces( client: LangfuseAnalyticsClient, args: z.infer<typeof topExpensiveTracesSchema> ) { const tags = args.environment ? [`environment:${args.environment}`] : undefined; const response = await client.listTraces({ fromTimestamp: args.from, toTimestamp: args.to, orderBy: 'totalCost', orderDirection: 'desc', // Most expensive first limit: args.limit, tags, }); const traces: ExpensiveTrace[] = []; // Parse the response data - correct structure based on Langfuse API if (response.data && Array.isArray(response.data)) { response.data .filter((trace: any) => (trace.totalCost || 0) > 0) // Only include traces with cost .sort((a: any, b: any) => (b.totalCost || 0) - (a.totalCost || 0)) // Sort by cost descending .slice(0, args.limit) // Limit results .forEach((trace: any) => { traces.push({ traceId: trace.id, name: trace.name || 'Unnamed trace', totalCost: trace.totalCost || 0, totalTokens: trace.totalTokens || 0, timestamp: trace.timestamp || trace.startTime, userId: trace.userId, tags: trace.tags || [], metadata: trace.metadata, }); }); } return { content: [ { type: 'text' as const, text: JSON.stringify( { projectId: client.getProjectId(), from: args.from, to: args.to, environment: args.environment, traces, }, null, 2 ), }, ], }; }