# Event **Meta-Universe Specification** **Document ID:** MU-V2-CORE-007 **Title:** Event — The Evolution of Semantic Reality **Document Class:** Normative **Version:** 2.0 (Draft) **Status:** Working Draft **Normative References:** MUC, MMAS, MUFP **Informative References:** [Object](../04-core-concepts/Object.md), [Relationship](../04-core-concepts/Relationship.md), [Lifecycle](../04-core-concepts/Lifecycle.md), [Traceability](../02-architecture/Traceability.md) **Copyright:** © Orkestron.AI **License:** Apache-2.0 --- # 1. Purpose This document defines the concept of an **Event** within the Meta-Universe. An Event is a first-class semantic entity that records how semantic reality evolves. Where an [Object](../04-core-concepts/Object.md) answers *what exists* and a [Relationship](../04-core-concepts/Relationship.md) answers *how things are connected*, an Event answers a different question: **why the world became the way it is.** An Event is not merely a change log entry. It is the unit through which the Meta-Universe remembers its own history. --- # 2. Definition An Event is an immutable semantic assertion that something meaningful happened to a Meta-Object, a Relationship, a Projection, a Contract or a Universe at a specific point in time. An Event SHALL: - describe a meaningful change or occurrence; - reference the semantic entities it affects; - declare when it occurred and who asserted it; - remain immutable once recorded. Events accumulate. They are never overwritten. The present state of any semantic entity is derivable from the sequence of Events that produced it. --- # 3. Principles - **Events are immutable.** History is not edited; it is appended to. - **State is derived.** The current state of an entity is a projection of its Event history, not an independent source of truth. - **Events carry meaning, not just data.** An Event records intent and cause, not only the changed value. - **Events are traceable.** Every Event declares its provenance. - **Events are federation-aware.** An Event may be disclosed to another Universe through a [Semantic Contract](../04-core-concepts/Contract.md), never leaked implicitly. --- # 4. Scope This document applies to: - Events affecting Meta-Objects, Relationships, Projections, Contracts and Universes; - the temporal model used to order and interpret Events; - the reconstruction of historical state from Events; - the disclosure of Events during federation. It does not define the storage or transport technology used to persist or transmit Events. --- # 5. Components of an Event Every Event SHALL declare: | Component | Meaning | |-----------|---------| | **Identity** | A stable identifier for the Event itself. | | **Type** | The category of occurrence (see Section 6). | | **Subject** | The Meta-Object, Relationship, Projection or Contract affected. | | **Timestamp** | When the Event occurred. | | **Provenance** | Who asserted the Event and on what authority. | | **Payload** | The semantic content of the change. | | **Causality** | References to the Events or facts that caused it (optional but RECOMMENDED). | --- # 6. Categories of Events Events SHOULD be classified to support reasoning and federation: - **Lifecycle Events** — creation, activation, deprecation, retirement of an entity. - **Structural Events** — a Relationship is established, modified or dissolved. - **Semantic Events** — the meaning, classification or interpretation of an entity changes. - **Disclosure Events** — knowledge is disclosed under a Semantic Contract (see [Consent and Disclosure](../03-federation/Consent-and-Disclosure.md)). - **Federation Events** — a federation is established, suspended or terminated. - **Conflict Events** — a semantic conflict is detected or resolved (see [Conflict Resolution](../03-federation/Conflict-Resolution.md)). --- # 7. Temporal Model Every Event SHALL be associated with at least one time: - **Occurrence Time** — when the change happened in reality. - **Assertion Time** — when the change was recorded in the Universe. These MAY differ. A change in the real world may be recorded later, and the difference itself is semantically meaningful. Implementations SHOULD preserve both so that history can be reconstructed either as *what was true* or as *what was known*. --- # 8. Identity, Provenance and Immutability Each Event SHALL possess a stable [Identity](../04-core-concepts/Identity.md), independent of the entities it affects. Each Event SHALL declare its [provenance](../02-architecture/Traceability.md): the actor, the authority under which it was asserted, and the source of the assertion. Once recorded, an Event SHALL NOT be modified or deleted. Corrections are themselves expressed as new Events that reference the Event being corrected. This preserves historical integrity and prevents silent rewriting of the past. --- # 9. Causality Events MAY reference the Events or facts that caused them, forming a causal graph. Causality allows an AI agent or auditor to answer not only *what changed* but *why it changed* and *what followed from it*. Causality links are the temporal counterpart of [Semantic Lineage](../02-architecture/Traceability.md): lineage explains the origin of meaning across entities; causality explains the origin of change across time. --- # 10. Federation of Events Events are not automatically shared between Universes. An Event MAY be disclosed to another Universe only: - through a [Projection](../04-core-concepts/Projection.md) appropriate to the recipient's context, and - governed by a [Semantic Contract](../04-core-concepts/Contract.md) that defines which Events, for which Purpose, may be disclosed. This allows a Universe to notify a federated partner of relevant change without surrendering its full history. --- # 11. Event Streams A sequence of related Events forms an **Event Stream**. Event Streams are the mechanism through which Universes observe meaningful change over time. A federated partner MAY subscribe — under contract — to a stream of Disclosure or Lifecycle Events relevant to an agreed Purpose, rather than repeatedly polling for current state. --- # 12. Semantic Timeline The full set of Events forms more than a journal. It forms a **Semantic Timeline** — a reconstructable picture of semantic reality at any point in time. Because state is derived from Events, the Meta-Universe can answer historical questions that conventional systems cannot: - *What did the organization's structure look like on 1 January 2025?* - *Which knowledge was available to an agent before a new contract was signed?* - *Which objects existed before two departments were merged?* The Semantic Timeline turns the Meta-Universe into a **time machine for knowledge**: any past state of any entity, relationship or projection can be reconstructed by replaying the Events that produced it. This capability underpins auditability, explainable AI reasoning and conflict reconstruction across federated Universes. --- # 13. Validation An Event model conforms to this specification when: - every Event is immutable and uniquely identified; - every Event declares a subject, type, timestamp and provenance; - current state is derivable from the Event history; - corrections are expressed as new Events, never as edits; - federated Events are disclosed only under explicit contracts. See [Validation](../02-architecture/Validation.md) for the validation levels that apply. --- # 14. Architectural Invariants - Events SHALL be immutable. - State SHALL be derivable from Events. - Events SHALL declare provenance. - Events SHALL NOT cross Universe boundaries without an explicit Semantic Contract. - History SHALL NOT be rewritten; only appended to. --- # Future Directions The Semantic Timeline may evolve into a dedicated capability for **temporal querying and reconstruction** across federated Universes — a standardized way to ask "show me this semantic reality as of date *T*" and receive a verifiable, contract-governed answer. This would build directly on the Event model defined here and on [Traceability](../02-architecture/Traceability.md). --- # Final Statement > An Object tells us what exists. A Relationship tells us how it connects. An Event tells us why the world became the way it is — and lets us return to any moment it has ever been.