Agent systems can inspect models, tools, retrievals, costs, and outcomes. When a person enters the system, that shared operational picture becomes incomplete.
The person is usually represented by an action: approved, rejected, corrected, intervened. The changing human process that produced the action remains outside the system.
Human Runtime, or HRT, closes that gap.
HRT converts human-performance inputs into agent-native states, events, and traces. It gives agents and operational systems a structured way to work with relevant changes in human capacity, perception, behaviour, and action.
Observability is the starting point. It is not the limit.
From observable to integrated
A system must perceive a relevant change before it can respond intelligently. Once human-runtime information is available, it can support more than monitoring.
- An agent can calibrate confidence in a human intervention.
- An interface can adapt to available attention or context headroom.
- A training system can compare performance across attempts.
- A safety system can identify a degrading handover before the outcome is known.
- An operational workflow can route a decision to a person who currently has the right capacity and context.
- A product can create new services around human–agent coordination.
The same HRT output can create different value in different environments. A measured reduction in context headroom may affect a pilot, an AI reviewer, a technician, or a racing driver in very different ways.
HRT supplies the common structure. Each vertical supplies its domain knowledge, operating constraints, and product logic.
The HRT stack
The stack connects inputs from the human and the task environment to systems that can act on them.
- Inputs — sensors, interfaces, behaviour, task events, and existing software telemetry.
- Core — the protocol, processor, shared data model, confidence model, and runtime services.
- Integration — APIs, events, agent tools, policies, and synchronized timelines.
- Verticals — domain-specific interpretation, workflows, integrations, and products.
This structure is deliberately horizontal. The core does not need to know how to fly an aircraft, supervise an AI agent, run a factory, or coach a driver. It needs to represent what can be known about the human runtime—with timestamps, definitions, provenance, uncertainty, and validity conditions.
Companies can then integrate HRT into existing systems, combine its output with proprietary data, or build vertical products on top of the stack.
A vocabulary for agent systems
Human-facing language and machine-facing language do not need to be identical.
Human Node describes the person as an active, changing part of an intelligent system. Inside the protocol, that person can have an addressable representation: a CogNode.
The wider protocol vocabulary can include:
CogNode— the addressable representation of a human node.CogSpan— a bounded period of human activity, state, or interaction.CogTrace— connected spans placed on the shared human–machine timeline.CogEvent— an observed change, action, intervention, or handover.CogState— a derived estimate with confidence, provenance, and validity conditions.
These objects do not claim access to private thought or complete knowledge of cognition. They represent measurable, operationally relevant observations and estimates. Uncertainty is part of the object rather than an inconvenient footnote.
The result is a vocabulary agents can query, systems can exchange, and people can audit.
Vertical products build above the protocol
HRT is not a single aviation product, human-in-the-loop dashboard, or cognitive analytics package.
Those are possible implementations.
An aviation company could use HRT to improve handovers, training, or crew–automation coordination. An agent platform could use it to interpret approvals and escalation. A racing organization could connect driver state to vehicle telemetry. An industrial operator could combine HRT with alarms, procedures, and control-room events. A training company could build adaptive instruction around the same protocol.
Some partners may expose HRT directly. Others may integrate it invisibly into a larger product. Both expand the value and reach of the stack.
This creates an ecosystem rather than a catalogue of isolated use cases:
HRT provides the shared human-runtime layer. Vertical builders turn that layer into domain value.
The reference point for Human Runtime
humanruntime.org is the reference and coordination point for this emerging layer.
It brings together the core definitions, protocol, processor, research, failure analysis, integration patterns, and vertical applications. It can document what HRT means while allowing many companies to create products from it.
The Topic Sorter supports that work. It helps investors, partners, and adopters learn the concepts, relate them to a specific environment, and reveal promising integrations. It is an onboarding and discovery tool—not the HRT core.
The larger objective is straightforward:
Make the human runtime legible, interoperable, and useful inside agentic systems.