---
id: T01
parent: S03
milestone: M004
provides: []
requires: []
affects: []
key_files: ["backend/schemas.py", "backend/routers/techniques.py"]
key_decisions: ["Populate video_filename via post-processing loop rather than from_attributes auto-mapping, since the field comes from a joined relation not a direct column"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "Rebuilt chrysopedia-api container on ub01 and verified: (1) wave-shaping-synthesis-m-wave-shaper returns 13 key moments all with video_filename populated, (2) second technique page returns 2 moments with video_filename, (3) all existing fields unchanged, (4) assertion script confirms all moments have video_filename and at least one is non-empty."
completed_at: 2026-03-30T06:49:59.009Z
blocker_discovered: false
---

# T01: Added video_filename field to KeyMomentSummary schema and populated it via chained selectinload in the technique detail endpoint

> Added video_filename field to KeyMomentSummary schema and populated it via chained selectinload in the technique detail endpoint

## What Happened
---
id: T01
parent: S03
milestone: M004
key_files:
  - backend/schemas.py
  - backend/routers/techniques.py
key_decisions:
  - Populate video_filename via post-processing loop rather than from_attributes auto-mapping, since the field comes from a joined relation not a direct column
duration: ""
verification_result: passed
completed_at: 2026-03-30T06:49:59.009Z
blocker_discovered: false
---

# T01: Added video_filename field to KeyMomentSummary schema and populated it via chained selectinload in the technique detail endpoint

**Added video_filename field to KeyMomentSummary schema and populated it via chained selectinload in the technique detail endpoint**

## What Happened

Added `video_filename: str = ""` to the KeyMomentSummary Pydantic schema. Chained `.selectinload(KeyMoment.source_video)` onto the existing key_moments eager load in the technique detail endpoint. Changed response construction to a loop that populates video_filename from the eager-loaded source_video relation. Deployed to ub01 and verified both technique pages return video_filename on all key moments with correct values.

## Verification

Rebuilt chrysopedia-api container on ub01 and verified: (1) wave-shaping-synthesis-m-wave-shaper returns 13 key moments all with video_filename populated, (2) second technique page returns 2 moments with video_filename, (3) all existing fields unchanged, (4) assertion script confirms all moments have video_filename and at least one is non-empty.

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `ssh ub01 'docker compose build chrysopedia-api'` | 0 | ✅ pass | 8000ms |
| 2 | `ssh ub01 'docker compose up -d chrysopedia-api'` | 0 | ✅ pass | 5000ms |
| 3 | `ssh ub01 'curl -s .../techniques/wave-shaping-synthesis-m-wave-shaper | python3 assert video_filename'` | 0 | ✅ pass | 1000ms |
| 4 | `ssh ub01 'curl -s .../techniques/balancing-softness-... | python3 check video_filename'` | 0 | ✅ pass | 1000ms |


## Deviations

None.

## Known Issues

None.

## Files Created/Modified

- `backend/schemas.py`
- `backend/routers/techniques.py`


## Deviations
None.

## Known Issues
None.
