SecFundamentalsImporter (SourceImporter, source=sec_facts): populates immutable
fundamental_snapshots from Company Facts and back-fills tickers.cik/sic, driven
by the EDGAR daily index. Shadow only. Guardrails per review:
- detect_revision caches the resolved universe + exact tracked index rows and
composes the revision from them; stage consumes those same cached inputs
(no index/universe refetch) so promoted data matches the computed revision.
- Resolution is read-only in stage (proposals only); ticker writes happen in
promote via apply_ticker_updates.
- validate runs the index<->Company-Facts consistency gate before any write:
a tracked XBRL index accession missing from Company Facts fails the run
(they lag independently) so we retry, not record null. Non-XBRL amendments
are skipped with a recorded reason. Backfill has a coverage floor.
- promote inserts ON CONFLICT (accession) DO NOTHING (immutable), reports
differing existing accessions without mutating, and applies ticker updates in
the same transaction.
- Full-history backfill on first run / for newly-added issuers (include_history);
incremental fetch only for issuers that filed.
Parser: split parse result into skipped_filings vs field_issues (coverage must
not count field warnings); header notes the us-gaap shares fallback; added
companyfacts_accessions() for the gate.
Verified live end-to-end (AAPL + GOOGL backfill): 112 snapshots, cik/sic set,
GOOGL shares via us-gaap fallback, AAPL via dei. Tests: 6 importer (backfill,
incremental, consistency-gate fail, non-XBRL skip, read-only-on-failure,
conflict-discrepancy) + parser ParseResult updates.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
