TL;DR
The software infrastructure surrounding a core language model that enables it to interact with external tools, manage state, and execute multi-step workflows.
An agent harness acts as the operational layer that transforms a stateless language model into an active, goal-driven agent. While the base model provides the core reasoning and determines which actions to take, the harness is responsible for executing those actions, routing tool calls, enforcing permission boundaries, and recording process traces. This structural separation ensures that security policies, tool interfaces, and session state are managed deterministically outside the probabilistic model.
Why this matters for your business
It decouples intelligence from execution, allowing companies to seamlessly swap out underlying language models without rewriting their entire application infrastructure.
