llm-observability

Trace LLM calls and track token costs across LangSmith, LangFuse, and Phoenix.

5|1|Updated Jun 17, 2026
One-click install
npx skills add https://github.com/roanbrasil/engineer-grade-agent-skills --skill llm-observability-roanbrasil
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: llm-observability
Source: https://github.com/roanbrasil/engineer-grade-agent-skills/tree/main/skills/llm-observability
Command: npx skills add https://github.com/roanbrasil/engineer-grade-agent-skills --skill llm-observability-roanbrasil

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Traditional application performance monitoring (APM) tools are built for deterministic systems with fixed latency and predictable costs, making them ineffective for LLM applications that have non-deterministic outputs, variable latency, token-based pricing, and prompt versioning requirements that directly impact output quality and cost.

Core Features & Use Cases

  • Multi-Platform Tracing: Integrate with LangSmith, LangFuse, and Phoenix/Arize to trace LLM calls, RAG pipeline steps, and agent workflows across any LLM provider.
  • LLM-Specific Metrics: Track input/output token counts, per-call cost, latency percentiles, cache hit rates, and LLM-specific errors like rate limits, context length breaches, and content filter blocks.
  • Prompt Versioning & Evaluation: Version prompts like code, link production traces to evaluation datasets, and track performance changes across prompt iterations.
  • Use Case: A team running a production RAG customer support bot can use this skill to identify which prompt versions reduce hallucination rates, catch latency spikes in the retrieval step, and monitor daily cost against budget thresholds.

Quick Start

Use the llm-observability skill to set up end-to-end tracing, cost tracking, and alerting for your production LLM application.

Frequently Asked Questions about llm-observability

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I monitor LLM application performance and token costs in production?

To monitor LLM application performance and token costs, you need specialized observability that tracks input/output token counts, per-call cost, and latency percentiles for non-deterministic LLM workloads. This provides end-to-end trace collection and alerting for production RAG pipelines and agent systems.

Why does traditional APM not work for monitoring RAG pipelines and agent workflows?

Traditional APM fails for monitoring RAG pipelines because it is built for deterministic systems with fixed latency and predictable costs. LLM applications require observability for non-deterministic outputs, variable token-based pricing, and prompt versioning that traditional tools cannot track effectively.

Can I track prompt versioning and link production traces to evaluation datasets?

Yes, you can track prompt versioning and link production traces to evaluation datasets. This allows you to version prompts like code, track performance changes across prompt iterations, and identify which prompt versions reduce hallucination rates in your LLM application.

Does this observability approach integrate with LangSmith, LangFuse, and Phoenix?

Yes, this observability approach integrates with LangSmith, LangFuse, and Phoenix/Arize to trace LLM calls, RAG pipeline steps, and agent workflows. It captures LLM-specific metrics like cache hit rates, rate limits, and context length breaches across any LLM provider.

What is the best way to catch latency spikes and monitor daily cost against budget thresholds for LLM apps?

The best way to catch latency spikes and monitor daily cost against budget thresholds is to implement LLM-specific metric collection and performance alerting. This traces retrieval steps in RAG pipelines and categorizes LLM-specific errors like content filter blocks to maintain application reliability.