What is an AI agent harness?
An AI agent harness is everything around the model that makes an agent operable: orchestration, the tools it may call and with what permissions, what it may retain, evaluation, guardrails, logging and a way to stop it. The model provides reasoning; the harness decides what that reasoning is allowed to touch.
A harness for an established enterprise estate adds four things:
- Boundaries: what the agent may call, on whose authority, and what data never leaves your environment.
- Structured outputs and defined failure modes, so downstream systems receive something they can validate and reject.
- Fallbacks and a documented rollback, tested before go-live.
- Observability that your operations team can use: logs, traces and alerts in the tools they already watch.
The design follows a simple idea from software architecture. Bounded contexts give clear limits on what an agent may call; composition decides how tools, evaluation and guardrails stack on top of each other.