---
id: T01
parent: S01
milestone: M012
provides: []
requires: []
affects: []
key_files: ["backend/search_service.py", "backend/schemas.py", "backend/routers/search.py", "backend/tests/test_search.py"]
key_decisions: ["TechniquePage keyword search JOINs Creator for cross-field token matching", "partial_matches only triggers on multi-token queries with zero AND results", "keyword_search returns dict with items + partial_matches instead of flat list"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "All 19 search tests pass (13 existing updated for new return shape + 6 new tests covering multi-token AND logic, cross-field matching, partial_matches, topic_tags via array_to_string, and creator genres matching). All 3 source files pass AST syntax validation."
completed_at: 2026-04-01T06:15:17.535Z
blocker_discovered: false
---

# T01: Refactored keyword_search to multi-token AND with cross-field matching and partial_matches fallback

> Refactored keyword_search to multi-token AND with cross-field matching and partial_matches fallback

## What Happened
---
id: T01
parent: S01
milestone: M012
key_files:
  - backend/search_service.py
  - backend/schemas.py
  - backend/routers/search.py
  - backend/tests/test_search.py
key_decisions:
  - TechniquePage keyword search JOINs Creator for cross-field token matching
  - partial_matches only triggers on multi-token queries with zero AND results
  - keyword_search returns dict with items + partial_matches instead of flat list
duration: ""
verification_result: passed
completed_at: 2026-04-01T06:15:17.536Z
blocker_discovered: false
---

# T01: Refactored keyword_search to multi-token AND with cross-field matching and partial_matches fallback

**Refactored keyword_search to multi-token AND with cross-field matching and partial_matches fallback**

## What Happened

Rewrote SearchService.keyword_search() from single-pattern ILIKE to multi-token AND architecture. Each token generates OR conditions across entity fields (title, summary, topic_category, topic_tags, creator name), all AND'd together. TechniquePage now JOINs Creator for cross-field matching. Added partial_matches fallback that scores by token coverage when AND yields zero results on multi-token queries. Extended SearchResponse schema with partial_matches field and threaded it through the router.

## Verification

All 19 search tests pass (13 existing updated for new return shape + 6 new tests covering multi-token AND logic, cross-field matching, partial_matches, topic_tags via array_to_string, and creator genres matching). All 3 source files pass AST syntax validation.

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `python -m pytest tests/test_search.py -x -v` | 0 | ✅ pass | 8880ms |
| 2 | `python -c "import ast; ast.parse(open('search_service.py').read())"` | 0 | ✅ pass | 200ms |
| 3 | `python -c "import ast; ast.parse(open('schemas.py').read())"` | 0 | ✅ pass | 200ms |


## Deviations

Used integration tests against PostgreSQL test DB via SSH tunnel instead of localhost:8001 curl since API runs in Docker on ub01.

## Known Issues

None.

## Files Created/Modified

- `backend/search_service.py`
- `backend/schemas.py`
- `backend/routers/search.py`
- `backend/tests/test_search.py`


## Deviations
Used integration tests against PostgreSQL test DB via SSH tunnel instead of localhost:8001 curl since API runs in Docker on ub01.

## Known Issues
None.
