GoldenMatch

goldenmatch 1.18.0 -- 2026-05-22

Addresses all four follow-up items from the golden-field
consolidation discussion + adds post-cluster auto-config refinement.

Three new built-in strategies

• longest_value -- longest non-null string. Free-text use case.
• unanimous_or_null -- emit value only on full agreement; emit
  None on any disagreement. Compliance use case.
• confidence_majority -- majority weighted by cluster pair_scores.
  Strong-edge minority can beat weak-edge majority.

Post-cluster GoldenRulesRefiner

Two-phase auto-config: matchkey + blocking stays pre-cluster
(clustering depends on them); golden-rules picking moves
POST-cluster where it benefits from real cluster shape signals.

core/golden_rules_refiner.py runs between build_clusters and
build_golden_records when golden_rules.adaptive=True. Reads:

• Compliance column-name patterns (ssn / npi / tax_id / license /
  dob / mrn / passport / hipaa_id / cusip / lei / isin / etc.)
• High-cardinality identifier columns
• Sibling timestamp detection (updated_at / modified_at / etc.
  with > 80% coverage)
• Within-cluster value spread
• Per-source completeness (uses source if present)
• Date-column timestamp coverage
• ColumnProfile signals (col_type, avg_len, null_rate)

Rule table:

1. (PRE) compliance column name -> unanimous_or_null
2. (PRE) col_type=identifier + cardinality > 0.9 -> unanimous_or_null
3. col_type=date + > 50% cluster coverage -> most_recent
4. Mutable field + sibling timestamp -> most_recent on the sibling
5. One source > 1.5x median completeness -> source_priority
6. Free-text + long + within-cluster disagreement -> longest_value
7. null_rate > 0.5 -> first_non_null
8. spread > 2.0 -> confidence_majority
9. Else -> defer to base default

Opt-in via GoldenRulesConfig.adaptive: bool = False (default off).
Default-on is a v1.19 candidate after benchmark validation.

Custom plugin slot

strategy="custom:<name>" looks up a registered GoldenStrategyPlugin.
Rich protocol signature (values + sources + dates + quality_weights

• pair_scores + rule_kwargs). Defensive defaults: missing plugin OR
  plugin exception -> WARNING + most_complete fallback. Opt-in strict
  mode via GOLDENMATCH_GOLDEN_STRATEGY_STRICT=1.

Specs

• docs/superpowers/specs/2026-05-22-intelligent-golden-rules-design.md
• docs/superpowers/specs/2026-05-22-golden-strategy-plugin-slot-design.md

Full CHANGELOG: https://github.com/benseverndev-oss/goldenmatch/blob/v1.18.0/packages/python/goldenmatch/CHANGELOG.md