What is agent harness engineering?
An AI agent is a model plus a harness. The harness is everything except the model: tools, context, prompts, memory, hooks, guardrails, and feedback loops. Agent harness engineering is the discipline of designing, measuring, and improving that harness so agents are reliable in production.
See the Concepts glossary for short definitions of agent harness, agent observability, agent evals, guardrails, and related terms.
- Observe
- Develop
- Coding Agents
- Improve
- Manage
- Otter
LLM observability and AI agent observability for agents built with CrewAI, LangGraph, or any agent framework. OpenLIT brings OpenTelemetry-native instrumentation so you can analyze how your agents perform in production with full stack visibility:
- Tracing - Instrument once via OpenTelemetry-native SDKs for 90+ LLMs and agent frameworks to produce OpenTelemetry traces.
- Lowest level transparency - Exceptions Monitoring surfaces errors with full stack traces and span context so you know exactly where and why something failed. All telemetry is automatically redacted for sensitive data before it leaves your stack.
- Understand cost and latency - Track token consumption, spend per model, provider, and request. Monitor GPU utilization alongside LLM call latency in custom dashboards built on your raw telemetry.
Get Started
Instrument an AI Agent
Production-ready AI Observability in 2 steps with zero code changes
Observe coding agents
Track spend and usage for Claude Code, Cursor, & more across teams
Deploy OpenLIT
Self-host the full platform with Docker Compose or Helm
Evaluate LLM responses
Score live traces automatically with prebuilt LLM-as-a-judge evaluators
Frequently asked questions
What is OpenLIT?
What is OpenLIT?
OpenLIT is an open-source agent harness engineering platform. It provides OpenTelemetry-native tracing, evaluations, guardrails, prompt management, and cost and GPU monitoring for AI agents and coding agents, and it is free to self-host under Apache 2.0.
What is an agent harness?
What is an agent harness?
An agent harness is everything in an AI agent except the model: the tools, context, prompts, memory, hooks, guardrails, and feedback loops that turn a model into a working agent. Claude Code, Codex, and frameworks such as LangGraph or CrewAI are harnesses; OpenLIT observes, evaluates, and improves any of them via OpenTelemetry.
What is agent harness engineering?
What is agent harness engineering?
Agent harness engineering is the discipline of designing, measuring, and improving everything around the model in an AI agent so the agent is reliable in production. Teams observe failures in traces, evaluate them, fix the harness, and verify the fix. OpenLIT is the open-source platform for that loop.
Is OpenLIT open source?
Is OpenLIT open source?
Yes. OpenLIT is fully open source under Apache 2.0 and self-hostable via Docker Compose or Helm, so your telemetry and prompts never have to leave your infrastructure.
Does OpenLIT require code changes to instrument my app?
Does OpenLIT require code changes to instrument my app?
No. OpenLIT’s SDK auto-instruments 70+ LLMs, agent frameworks, and vector databases with zero code changes, or you can call
openlit.init() once for manual instrumentation if you want more control - both produce the same OpenTelemetry traces.Can OpenLIT send data to my existing observability stack?
Can OpenLIT send data to my existing observability stack?
Yes. Because OpenLIT is OpenTelemetry-native, you can export traces and metrics to Grafana, Datadog, New Relic, SigNoz, or any OTLP-compatible backend - see Destinations.

