Changelog

April 2026

Band-primary slab pricing

Developer routes now use a band-primary weighting for grades 7-9. The composite band TWAP is the primary reference price; grader-specific observations act as a differentiator. Monotonicity is enforced per grader (grade 7 <= grade 8 <= grade 9 <= grade 10).

Era-aware gem-10 ratios

Gem-10 anchor ratios are now split by metadata.era. Modern and vintage cards use separate calibration tables, reflecting their distinct secondary market dynamics.

30-day composite band window

The composite band TWAP leg for grades 7-9 uses a 30-day rolling window on live oracle calls.

New meta keys: grade_band_twap_effective_window_hours, slab_grade_band_live_historical_band_window.

Upstream resilience on ID lookup

The /developer/pricecharting/{id} route now handles 404 and 410 responses from the upstream pricing source. Products with a known local catalog mapping continue to return pricing from Coda's own observation database.

Sparse oracle ridge WLS

Added a ridge WLS linear forecast for the stale-history case (no primary-window observations but sufficient data in the 30-day extended window). The forecast is blended with a recency-weighted mean and clamped to the observed range.

New meta fields: twap_stale_history_wls_forecast, twap_stale_wls_blend, twap_stale_wls_y_hat_pre_blend, twap_stale_wls_recency_mean_minor.

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Initial Release

• TWAP oracle: twap_24h_outlier_v3_floor_q20
• PSA / BGS / CGC / SGC x grades 1-10 slab matrix
• Composite band blend for grades 1-9
• Sparse oracle with 30-day recency-weighted fallback
• Developer pricing and PriceCharting lookup routes
• Nightly ingest pipeline (PriceCharting + eBay)