---
phase: 06-frontmatter-classification
verified: 2026-02-23T00:00:00Z
status: passed
score: 4/4 must-haves verified
requirements-completed:
  - CLASS-04
  - CLASS-05
---

# Phase 6: Frontmatter Classification Verification Report

**Phase Goal:** The construct classifier reads YAML frontmatter from markdown files as a high-confidence signal, making `--construct` filtering reliably accurate
**Verified:** 2026-02-23
**Status:** passed

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | `corpus search --construct skill` returns files whose frontmatter declares `type: skill` at or near top of results | ✓ VERIFIED (partial) | `classify_by_frontmatter()` returns confidence 0.95 for `type: skill`; stored in LanceDB; search applies `WHERE construct_type='skill'` predicate (engine.py). High-confidence classification improves accuracy. Live ranking requires human verification. |
| 2 | A markdown file with a recognized frontmatter type declaration is classified with confidence ≥ 0.9 | ✓ VERIFIED | `classify_by_frontmatter()` returns `ClassificationResult(val, 0.95, "frontmatter")` for `type:` and `component_type:` matches (classifier.py:87, 93); 12 tests confirm this behavior |
| 3 | Frontmatter `tags` field values are surfaced as classification signals | ✓ VERIFIED | `classify_by_frontmatter()` performs case-insensitive substring match on tags list (classifier.py:100-103); returns confidence 0.70; 4 dedicated tests cover tags behavior |
| 4 | Files without frontmatter continue to be classified with no regression | ✓ VERIFIED | `classify_file()` falls through to `classify_by_rules()` when frontmatter returns None; 8 existing rule-based tests updated and all pass; total 192 tests pass |

**Score:** 4/4 truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `src/corpus_analyzer/search/classifier.py` | `ClassificationResult` dataclass, `classify_by_frontmatter()`, updated `classify_file()` | ✓ EXISTS + SUBSTANTIVE | ClassificationResult at line 24 with construct_type, confidence, source fields; classify_by_frontmatter() at line 53; classify_file() gives frontmatter first priority |
| `src/corpus_analyzer/store/schema.py` | `classification_source`, `classification_confidence` on ChunkRecord; `ensure_schema_v3()` | ✓ EXISTS + SUBSTANTIVE | Fields at lines 159, 166; ensure_schema_v3() at line 68-81 idempotently adds columns using LanceDB add_columns API |
| `src/corpus_analyzer/ingest/indexer.py` | Extracts ClassificationResult; writes source/confidence to chunk dict | ✓ EXISTS + SUBSTANTIVE | classify_result extracted at line 201; .construct_type, .source, .confidence written to chunk dict at lines 246-248 |
| `tests/search/test_classifier.py` | 12 new tests for frontmatter classification | ✓ EXISTS + SUBSTANTIVE | 5 type tests, 3 fallthrough tests, 4 tags tests; all pass |
| `tests/ingest/test_indexer.py` | `test_indexer_stores_frontmatter_classification` | ✓ EXISTS + SUBSTANTIVE | Verifies `construct_type="skill"`, `classification_source="frontmatter"`, `classification_confidence=0.95` in LanceDB row |
| `tests/store/test_schema.py` | Updated `test_all_required_fields_present` | ✓ EXISTS + SUBSTANTIVE | New fields included in schema validation test |

**Artifacts:** 6/6 verified

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|----|--------|---------|
| Markdown file with `type: skill` | `classify_by_frontmatter()` | called first in `classify_file()` | ✓ WIRED | classifier.py:171-174: frontmatter is first priority |
| `classify_file()` return | `ClassificationResult` | indexer.py:201 | ✓ WIRED | `classify_result = classify_file(...)` then .construct_type/.source/.confidence accessed |
| `ClassificationResult` fields | LanceDB chunk dict | indexer.py:246-248 | ✓ WIRED | `chunk["construct_type"]`, `chunk["classification_source"]`, `chunk["classification_confidence"]` all set |
| Existing LanceDB tables | schema v3 columns | `ensure_schema_v3()` via `CorpusIndex.open()` | ✓ WIRED | Called unconditionally at indexer.py:105 on every open |
| `construct_type` in LanceDB | `corpus search --construct` | engine.py WHERE predicate | ✓ WIRED | High-confidence frontmatter values improve filter accuracy |

**Wiring:** 5/5 connections verified

## Requirements Coverage

| Requirement | Status | Blocking Issue |
|-------------|--------|----------------|
| CLASS-04: Classifier reads YAML frontmatter type/component_type/tags as signals | ✓ SATISFIED | — |
| CLASS-05: Recognized frontmatter type → confidence ≥ 0.9 | ✓ SATISFIED | Confidence is 0.95 (≥ 0.9) |

**Coverage:** 2/2 requirements satisfied

## Anti-Patterns Found

None. No TODOs, stubs, or placeholders in Phase 6 implementation.

Minor tech debt (not blockers):
- `indexer.py:139` — dead `use_llm_classification` formal parameter (method reads `source.use_llm_classification` directly)
- `indexer.py:374-375` — two consecutive bare `pass` statements in `close()`

## Human Verification Required

### 1. Search construct ranking with frontmatter
**Test:** Index a directory containing `.md` files with `type: skill` frontmatter; run `corpus search --construct skill <query>`; confirm frontmatter-classified files appear at or near top
**Expected:** Files with explicit frontmatter type appear in results; construct filter works correctly
**Why human:** Live Ollama embedder required for end-to-end search

## Gaps Summary

**No critical gaps found.** Phase goal achieved. `--construct` filtering now benefits from high-confidence (0.95) frontmatter classifications persisted in LanceDB.

## Verification Metadata

**Verification approach:** Goal-backward (derived from phase goal and ROADMAP.md success criteria)
**Must-haves source:** ROADMAP.md Phase 6 success criteria
**Automated checks:** 192 tests passing
**Human checks required:** 1 (live search ranking with real Ollama instance)
**Notes:** Schema migration (`ensure_schema_v3`) confirmed idempotent and safe for existing indexes

---
*Verified: 2026-02-23*
*Verifier: Claude (audit)*
