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Attributed Fact Extension

Canonical../StructureDefinition/nexus-attributed-fact
Statusdraft (experimental) · 1.26.0
BaseExtension (constraint)
ContextProvenance (element)
SourceFSH · JSON

One factual statement in a piece of AI-generated text, together with the citation(s) that back it: verbatim quotes from the source material the statement was derived from.

Overview

Repeats, in order, to carry the full fact list of a generated summary -- order is significant and MUST be preserved, because the facts compose the summary text. Each fact carries at least one citation by construction: the generating pipeline refuses to emit a citation-free fact, and this extension makes that guarantee structural (citation is 1..*).

The citation's chunk is the generating run's own label for the passage of source material the quote was copied from (for example c3). Chunk labels are opaque and are only meaningful relative to the run that produced this Provenance -- they are stable within one Provenance instance, not across instances. The quote is the verbatim, character-for-character text of the cited passage; it is the auditable part, and it remains checkable against the source document even after the run's chunking is gone. The optional source reference ties a citation to the specific Provenance.entity resource the chunk was drawn from, when the producer can resolve it.

This grain is deliberately finer than Provenance.entity: entity records which resources the activity read; this extension records which statement rests on which passage. A consumer that only needs "what were the inputs" should read entity and ignore this extension.