Set up comprehensive observability for Langfuse with metrics, dashboards, and alerts.
Use when implementing monitoring for LLM operations, setting up dashboards,
or configuring alerting for Langfuse integration health.
Trigger with phrases like "langfuse monitoring", "langfuse metrics",
"langfuse observability", "monitor langfuse", "langfuse alerts", "langfuse dashboard".
Set up monitoring for your Langfuse integration: Prometheus metrics for trace/generation throughput, Grafana dashboards, alert rules, and integration with Langfuse's built-in analytics dashboards and Metrics API.
Prerequisites
Langfuse SDK integrated and producing traces
For custom metrics: Prometheus + Grafana (or compatible stack)
For Langfuse analytics: access to the Langfuse UI dashboard
Instructions
Step 1: Langfuse Built-In Dashboards
Langfuse provides pre-built dashboards in the UI at https://cloud.langfuse.com (or your self-hosted URL):
Overview: Total traces, generations, scores, and errors
Cost Dashboard: Token usage and costs over time, broken down by model, user, session
Latency Dashboard: Response times across models and user segments
Custom Dashboards: Build your own with the query engine (multi-level aggregations, filters by user/model/tag)
Accessing via Metrics API:
import { LangfuseClient } from "@langfuse/client";
const langfuse = new LangfuseClient();
// Fetch aggregated metrics programmatically
const traces = await langfuse.api.traces.list({
fromTimestamp: new Date(Date.now() - 3600000).toISOString(), // Last hour
limit: 100,
});
console.log(`Traces in last hour: ${traces.data.length}`);
// Get observations with cost data
const observations = await langfuse.api.observations.list({
type: "GENERATION",
fromTimestamp: new Date(Date.now() - 86400000).toISOString(),
limit: 500,
});
const totalCost = observations.data.reduce(
(sum, obs) => sum + (obs.calculatedTotalCost || 0), 0
);
console.log(`Total cost (24h): $${totalCost.toFixed(4)}`);
Step 2: Prometheus Metrics for Your App
Track the health of your Langfuse integration with custom Prometheus metrics:
