Single Aggregate

Kind: constraint

Layer: Execution Core

Record: architecture:single-aggregate

Severity: mandatory

Scope: measurement, report

Canonical: Ontology

A rule or precondition that a shared measurement keeps one aggregate, overwritten by each run that can honestly replace it, while a run that cannot streams its verdict instead of writing a second report.

Listed in Architecture principles, after Joinable Mandated Field and before Contradicted Invariant.

Requires

• Read Population

Reinforces

• Single Source of Truth

Enables

• Traceable Guarantee

Conflicts with

• Invocation-Keyed Report
• Narrowed Aggregate

Violated by

• Invocation-Keyed Report
• Narrowed Aggregate

Refactored by

• Write the Aggregate Only from a Full Run
• Stream Narrowed Verdicts

Severity

• mandatory

Category

• Coordination Surfaces

Linked from

• Schema / Canonical Data / Semantics
• Coordination Surfaces
• Coordination Surfaces
• Severity levels

in this codebase

• models/substrate.model.md