Design (not implementation) for phase A3, grounded in live SEC data probes.
Key findings: fp has no Q4 (derive it); fy/fp are the filing's context not each
fact's period (select by end==reportDate); SEC provides both discrete and YTD
facts (confirms stored-YTD schema); companyfacts endpoint has no ETag/
Last-Modified (conditional GET impossible); tickers are dash-form and GOOG/GOOGL
share one CIK.
Two plan deviations flagged for sign-off:
1. Fetch via the EDGAR daily-index (fetch companyfacts only for tracked issuers
that filed) rather than the multi-GB bulk zip — lighter and restores the
revision/no_op model.
2. One snapshot row per accession for its primary period (YTD-cumulative);
comparative-only restatements out of scope (only real 10-K/A updates a period).
Plus a metric tag catalog, read-time derivation rules (missing period -> null),
CIK resolution, validation gates, and SEC fair-access handling.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
