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Langfuse Observability

Production observability with Langfuse.

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Environment Variables

export LANGFUSE_SECRET_KEY=sk-lf-...
export LANGFUSE_PUBLIC_KEY=pk-lf-...
export LANGFUSE_HOST=https://cloud.langfuse.com  # optional
VariableRequiredDescription
LANGFUSE_SECRET_KEYYesLangfuse secret key
LANGFUSE_PUBLIC_KEYYesLangfuse public key
LANGFUSE_HOSTNoCustom Langfuse host

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Features

FeatureSupported
Traces✅
Spans✅
Events✅
Errors✅
Metrics✅
Export✅

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Quick Start

1

Simple Usage

import { Agent, setObservabilityAdapter } from 'praisonai';
import { LangfuseObservabilityAdapter } from 'praisonai/observability';

// Initialize Langfuse adapter
const obs = new LangfuseObservabilityAdapter();
await obs.initialize();
setObservabilityAdapter(obs);

// Create agent with tracing
const agent = new Agent({
  name: 'TracedAgent',
  instructions: 'You are a helpful assistant.',
  llm: 'openai/gpt-4o-mini'
});

// Run with automatic tracing
const response = await agent.chat('Hello!');

// Flush traces to Langfuse
await obs.flush();
2

With Configuration

Adjust observability adapter options and agent settings for production — see the sections above.

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Multi-Agent Tracing

import { Agent, Agents, setObservabilityAdapter } from 'praisonai';
import { LangfuseObservabilityAdapter } from 'praisonai/observability';

const obs = new LangfuseObservabilityAdapter();
await obs.initialize();
setObservabilityAdapter(obs);

const researcher = new Agent({
  name: 'Researcher',
  instructions: 'Research topics.',
  llm: 'openai/gpt-4o'
});

const writer = new Agent({
  name: 'Writer',
  instructions: 'Write summaries.',
  llm: 'openai/gpt-4o-mini'
});

const agents = new AgentTeam({
  agents: [researcher, writer],
  tasks: [
    { agent: researcher, description: 'Research {topic}' },
    { agent: writer, description: 'Summarize findings' }
  ]
});

await agents.start({ topic: 'AI trends' });
await obs.flush();

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Troubleshooting

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Missing API Keys

Error: Langfuse SDK not available
Solution: Set both LANGFUSE_SECRET_KEY and LANGFUSE_PUBLIC_KEY.

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Traces Not Appearing

Solution: Ensure you call await obs.flush() before the process exits.

Langfuse CLI Usage

Langfuse CLI Usage

Observability Overview

Observability Overview