An agent harness is the infrastructure layer that makes an agent loop production-reliable.
What a Harness Typically Includes
- State management and checkpointing
- Retry logic and error recovery
- Guardrails and output validation
- Observability and tracing
- Stall detection and re-planning
Why It Matters
Many failures attributed to “the model” are actually harness failures: missing state, unclear recovery paths, silent tool errors, and weak logging.