agentlens-observe

Debug AI agents visually — Python SDK for AgentLens, the self-hosted AI agent observability platform.

Install

pip install agentlens-observe

Quick Start

import agentlens

agentlens.configure(server_url="http://localhost:8000")

@agentlens.trace(name="ResearchAgent")
def run_agent(query: str) -> str:
    with agentlens.span("web_search", "tool_call") as s:
        result = search(query)
        s.set_output(result)
        s.set_cost("gpt-4o", input_tokens=500, output_tokens=200)
    return summarize(result)

run_agent("Latest AI research papers")
# → Traces stream to your AgentLens dashboard

Features

• 2-line integration — @agentlens.trace decorator + agentlens.span() context manager
• Fire-and-forget — never blocks your agent (daemon thread transport)
• Async-safe — uses contextvars.ContextVar for trace propagation
• Cost tracking — built-in pricing for 12+ models (GPT-4o, Claude, etc.)
• Framework integrations — LangChain, CrewAI

Framework Integrations

LangChain / LangGraph

from agentlens.integrations.langchain import AgentLensCallbackHandler
agent.run("task", callbacks=[AgentLensCallbackHandler()])

CrewAI

from agentlens.integrations.crewai import patch_crewai
patch_crewai()  # Auto-instruments all Crew runs

License

MIT — see LICENSE