Provenance

Anti-fabrication's twin invariant: always cite. Every stored fact and every answer carries source lineage — which document it came from, and where inside it. There is no path that produces a number without also producing its origin.

Lineage starts at storage

Lineage is not bolted on at answer time — it is a NOT-NULL column at the bottom of the stack.

Structured facts (storage/fact_store.py)

The Fact dataclass's first ten fields are positional-frozen; two of them are lineage:

@dataclass
class Fact:
    metric_code: str
    entity: str
    geography: str
    channel: str
    period_type: str
    period: str
    value: float
    unit: str
    source_doc_id: str    # which document
    source_locator: str   # where inside it (e.g. slide=2,table=1,row=REVENUE,col=FY2024)
    ...

The fact_metric table declares both as TEXT NOT NULL. A fact cannot exist without knowing where it came from. (v2 adds optional version lineage too — source_file_hash, extractor_version, mapping_version — but those are additive.)

Narrative chunks (retrieval/chunking/chunk_store.py)

Each chunk carries doc_id + source_locator (TEXT NOT NULL), alongside metadata like title, entity, period, and sensitivity.

Lineage travels to the answer

from ragspine.agent.agent import answer_question
from ragspine.agent.llm_provider import MockProvider
from ragspine.storage.fact_store import FactStore

store = FactStore("data/fact_metric.db"); store.init_schema()
result = answer_question("中国内地FY2024的REVENUE是多少", store, MockProvider())
print(result.answer)   # number + （来源：… · …）
print(result.sources)  # [{'doc': 'ACME_FY2024_Review.pptx', 'locator': 'slide=2,table=1,...'}]

Where lineage must not be dropped

• Storage — never write a fact/chunk without its lineage columns; they are NOT NULL by design. (storage/CLAUDE.md: "never drop lineage".)
• Found-fact rendering — _structured_answer / _multi_subtask_answer must keep the source dict attached to each rendered line.
• Narrative synthesis — the citation backstop in _run_narrative exists precisely so a model that "forgets" to cite cannot strip provenance off the answer.
• The service edge — the /v1/ask mapping must carry sources through unchanged; a FAQ short-circuit hit carries its own source too (see FAQ short-circuit).