{
  "id": "agent-observability",
  "title": "See what your agent is doing",
  "category": "agents",
  "job": "Trace, debug and evaluate an agent in production.",
  "difficulty": "Intermediate",
  "tools": [
    {
      "id": "langfuse",
      "name": "Langfuse",
      "url": "https://langfuse.com",
      "kind": "observability",
      "summary": "Open-source tracing, evals and prompt management for LLM apps and agents.",
      "open_source": true,
      "pricing": {
        "plans": [
          {
            "name": "Hobby",
            "usd_month": 0,
            "note": "50k units/month, 2 users"
          },
          {
            "name": "Core",
            "usd_month": 29,
            "note": "100k units/month, unlimited users"
          }
        ],
        "source": "https://langfuse.com/pricing",
        "status": "verified",
        "notes": null
      },
      "last_checked": "2026-10-21"
    }
  ],
  "model": "Any",
  "mcp_servers": [],
  "config": {
    "filename": "env",
    "language": "bash",
    "code": "LANGFUSE_PUBLIC_KEY=\nLANGFUSE_SECRET_KEY=\nLANGFUSE_HOST="
  },
  "starter_prompt": "Add Langfuse tracing to every model call and tool call in this agent. Tag traces with user id and version. Then write an eval script that replays 20 saved traces and reports regressions.",
  "monthly_cost": {
    "min_usd": 0,
    "max_usd": 29,
    "note": "Langfuse Hobby free (50k units/month), Core $29 (100k units). Open source and self-hostable."
  },
  "steps": [
    "Add keys.",
    "Instrument model and tool calls.",
    "Review failing traces weekly."
  ],
  "why_this_works": "You can't fix what you can't see; traces turn vague bug reports into concrete steps.",
  "watch_out": "Don't log personal data you don't need.",
  "unverified": [],
  "tested": false,
  "last_checked": "2026-10-21"
}