The Intent Horizon: A Structural Primitive for Governed Agentic Operation Version: 0-1-seed Slug: intent-horizon Live page: https://nonsequitur.tech/pubs/white-papers/intent-horizon/ PDF: intent-horizon-v0-1-seed.pdf Abstract Governed agentic systems operate under a structural commitment that has been named in the architecture without being formally specified: the system is supposed to remain aligned with operator intent across time. The prior canon establishes what alignment requires — human-governed authority, curated context, agentically engineered execution, runtime verification (HGC³AE²) — and what the runtime enforcement of those commitments looks like (the Skipjack Protocol). The architecture downstream of those commitments — comprehension instrumentation, operational federation, reference-architecture synthesis — assumes the operator's intent is a coherent, time-bounded artifact that the system tracks against. This paper specifies the artifact. The intent horizon is the temporal and conceptual envelope within which a system's intent must remain coherent and operator-verifiable for the system to be operating as governed. Intent is the artifact (what the operator commits the system to doing); the horizon is the validity envelope of that artifact (how long, in what scope, under what observable boundary conditions). The horizon is not a metaphor; it is an architectural primitive with boundary conditions, failure modes, and operator-facing signals that can be read in real time. This paper develops the horizon construct in three movements. First, it documents five structural failures of agentic operation that the prior canon names without diagnosing — failures whose common shape is the unspecified-horizon condition (§2). Second, it specifies the horizon itself: what its boundary conditions are, what makes an intent horizon-integral or horizon-drifted, and what signals the operator reads to know which state holds (§3). Third, it situates the horizon within HGC³AE²'s role ordering — humans govern the horizon, curated context maintains the horizon's situational awareness, agentic execution operates within the horizon, and runtime verification reads the horizon's state (§4) — and shows what the Skipjack Protocol's enforcement mechanisms operationalize when the horizon is the primitive (§5). Released by zenodo-deposit workflow. Zenodo DOI auto-mints from this Release via the configured Zenodo-GitHub integration.