| Term | Definition |
|---|---|
| Agent | A system that consumes observations and produces actions through the protocol. |
| World | An endpoint implementing the world side of the protocol; source of observations, sink of actions. |
| Embodiment | A controllable presence a world offers to agents (arm, avatar, cursor). Bound to at most one session at a time unless the world declares shared control. |
| Entity | Anything a world reports in observations, including other agents’ embodiments. |
| Session | The negotiated contract binding an agent to zero or more embodiments, with granted channels, action types, and safety limits. |
| Observation channel | A named, typed stream of percepts declared in the world manifest. |
| Frame | One timestamped unit of a channel (an image, an event, a proprioception sample). |
| Action | A typed intent submitted by an agent, with a defined lifecycle. |
| Intent | The submitted form of an action, prior to acceptance. |
| Tick | One discrete world step in lockstep mode. |
| Session clock | The world’s monotonic nanosecond clock on which every ts_mono_ns is expressed; starts at session open. |
| Agent clock | The agent’s own monotonic nanosecond clock, related to the session clock by the offset estimated over heartbeat exchanges. |
| Clock offset | session clock − agent clock, estimated from the four timestamps of a ping exchange; its error is bounded by half the round-trip time. |
| Basis | The newest observation an intent relies on, named by its capture time in basis_ts_mono_ns. |
| Staleness | The age of an observation at the moment it is used: session-clock now minus its capture time. |
| Time model | Either lockstep or streaming; governs how the world advances relative to agent I/O. |
| Envelope | A quantitative safety limit (spatial, velocity, force, rate) enforced by the world. |
| Grant | An explicit permission attached to a session (action types, channels, embodiments). |
| Profile | A named conformance bundle adding requirements to Core (e.g. robotics). |
| Manifest | The self-description document exchanged at initialization (world manifest, agent manifest). |
Overview
Terminology
Normative definitions used throughout the specification.