Agent Harness vs Agent Runtime: What’s the difference?

In enterprise AI, the concepts of agent harness and agent runtime are often confused but serve distinct roles; the harness provides application-layer scaffolding that enables a model to function as an agent, while the runtime operates as the infrastructure-layer execution environment where the agent runs. The harness dictates how the agent processes information and interacts with tools, while the runtime ensures secure and isolated execution of tasks, enforcing resource limits and maintaining state. Separating these layers is crucial for effective governance, security, and observability, allowing for clear delineation of responsibilities such as input and output guardrails in the harness and network controls in the runtime. This separation also facilitates the creation of audit trails that link decision-making processes in the harness with execution tasks in the runtime, enhancing transparency and security. Credal is an enterprise AI platform that manages both layers, offering a managed harness to streamline application-layer tasks and a control plane to oversee authorization policies and audit trails across different agents.