---
title: 'Commit Review: R2 Video Storage Migration (fe74d1f)'
type: note
permalink: development/commit-review-r2-video-storage-migration-fe74d1f
---

# Commit Review: R2 Video Storage Migration

**Commit Hash:** fe74d1fc51103df2fb505a1cdc1f0e1f53845c3f
**Date:** December 12, 2025
**Author:** Sebastian Otaegui
**Type:** feat (feature addition)

## Overview

This commit implements a complete migration from Vercel blob storage to Cloudflare R2 for serving original videos. The change addresses MVP requirement #12 and introduces a flexible URL generation strategy supporting both public and presigned URLs.

## Key Changes

### Backend (app.py)

#### 1. **New `get_object_url()` Method** ✅
- **Location:** `R2StorageClient` class (lines 161-172)
- **Purpose:** Abstracts URL generation logic with fallback strategy
- **Implementation:**
  - Prefers public URL if `R2_PUBLIC_BASE_URL` is configured
  - Falls back to presigned URL with configurable expiration
- **Best Practice Alignment:** Matches Cloudflare R2 documentation patterns (from Exa context)
- **Code Quality:** Clean separation of concerns, well-documented

#### 2. **Configuration Enhancements** ✅
- Added `public_base_url` attribute (line 115)
- Added `presign_expiration_s` attribute with error handling (lines 117-122)
- Default: 3600 seconds (1 hour) for presigned URLs
- **Security:** Supports both public domains and custom R2 domains

#### 3. **Video Upload Strategy** ✅
- **UUID-based naming:** `{upload_id}{suffix}` instead of original filename (line 625)
- **Benefits:**
  - Prevents filename collisions
  - Maintains file extension for proper MIME types
  - Consistent naming across original/debug/results files
- **R2 Path Structure:**
  - Original videos: `videos/{jump_type}/{uuid}.mp4`
  - Results: `results/{jump_type}/{uuid}_results.json`
  - Debug videos: `debug_videos/{jump_type}/{uuid}_debug.mp4`

#### 4. **AnalysisResponse Extension** ✅
- Added `original_video_url` field (lines 62, 71, 92-93)
- Properly serialized in `to_dict()` method
- **Type Safety:** Optional field with `str | None`

### Frontend (React/TypeScript)

#### 1. **ResultsDisplay.tsx Changes** ✅
- **Smart URL Prioritization:** R2 URL > local blob URL > undefined (line 231)
- **useEffect Hook:** Proper cleanup of blob URLs to prevent memory leaks (lines 216-229)
- **Conditional Rendering:** Shows original video when either URL is available (line 232)
- **Download Links:** Both original and debug videos (lines 269-291)

#### 2. **Type Definitions** ✅
- Added `original_video_url?: string` to `AnalysisResponse` interface (frontend/src/types/api.ts)

#### 3. **Test Updates** ✅
- **ResultsDisplay.test.tsx:**
  - Added test for R2 original video URL rendering
  - Verified download link presence
- **UploadForm.test.tsx:**
  - Fixed React import (explicit import)
  - Added proper TypeScript interface
  - Fixed timestamp type (number vs ISO string)

### Dependencies

#### Frontend Package Updates ✅
- Added `@types/jest@^30.0.0` for better test type safety
- Updated yarn.lock with 366 new lines (Jest-related dependencies)

## Code Quality Assessment

### ✅ **Strengths**

1. **Conventional Commits:** Properly formatted commit message with scope
2. **Type Safety:** All new fields properly typed (TypeScript + Python)
3. **Error Handling:** OSError exceptions with proper logging
4. **Documentation:** Clear docstrings for `get_object_url()`
5. **Flexibility:** Supports both public and presigned URL strategies
6. **Memory Safety:** Proper blob URL cleanup in useEffect
7. **Testing:** Comprehensive test coverage for new features
8. **Logging:** Added URL logging for R2 uploads (lines 633-634)

### ⚠️ **Minor Concerns**

1. **Presigned URL Expiration:**
   - Default 1 hour may be too short for long analysis sessions
   - **Recommendation:** Consider 24 hours for production (86400s)
   - **Justification:** Videos should remain accessible after analysis

2. **Missing Backend Tests:**
   - No explicit backend tests for `get_object_url()` method
   - Search didn't find tests for `original_video_url` in backend
   - **Recommendation:** Add unit tests for R2StorageClient methods

3. **Public URL Configuration:**
   - `R2_PUBLIC_BASE_URL` not documented in commit message
   - **Missing:** Deployment documentation for environment variable
   - **Recommendation:** Update deployment checklist

4. **Frontend Type Import:**
   - Explicit `import React` added to test files (lines 174, 300)
   - This is unnecessary with React 17+ JSX transform
   - **Note:** May be required by test setup (vitest)

### 📋 **Compliance with Project Standards**

| Standard | Status | Notes |
|----------|--------|-------|
| Conventional Commits | ✅ | `feat:` prefix, clear description |
| Type Safety | ✅ | All new code properly typed |
| Test Coverage | ⚠️ | Frontend tested, backend needs tests |
| Documentation | ⚠️ | Code documented, deployment docs needed |
| Error Handling | ✅ | Proper exception handling with logging |
| Code Duplication | ✅ | No new duplication introduced |
| Linting | ✅ | Follows project formatting standards |

## Best Practices Validation

### Cloudflare R2 Best Practices (from Exa research)

1. **✅ Presigned URLs:** Correctly implemented with boto3 client
2. **✅ Public URLs:** Supports custom domain configuration
3. **✅ S3-Compatible API:** Uses standard boto3 S3 client
4. **✅ Error Handling:** OSError wrapping for R2 operations

### FastAPI Best Practices (from Ref documentation)

1. **⚠️ Response Models:** Uses custom `AnalysisResponse` class instead of Pydantic
   - **Current:** Manual `to_dict()` serialization
   - **Better:** Use `@dataclass` with FastAPI's dataclass support
   - **Trade-off:** Current approach works fine, but less idiomatic

### React Best Practices

1. **✅ useEffect Dependencies:** Correctly specified `[videoFile]`
2. **✅ Cleanup Functions:** Revokes blob URLs on unmount
3. **✅ Conditional Rendering:** Proper boolean coercion with `Boolean()`
4. **✅ Test Coverage:** Tests for new URL prioritization logic

## Performance Impact

### Positive
- **Reduced Vercel bandwidth:** Videos served from R2 (cheaper)
- **Better CDN support:** R2 has global edge caching
- **No frontend blob creation:** When R2 URL is available

### Neutral
- **Upload time:** Still uploads to R2 (no change)
- **Analysis time:** No impact on kinemotion processing

### Potential Issues
- **Presigned URL expiration:** Short-lived URLs may break if page stays open
  - **Mitigation:** Increase expiration to 24 hours

## Security Considerations

### ✅ **Good**
- UUID-based filenames prevent enumeration attacks
- Configurable expiration for presigned URLs
- Supports both private (presigned) and public (CDN) strategies

### ⚠️ **Consider**
- Public URLs expose video content to anyone with the link
- **Recommendation:** Document security trade-offs in deployment guide
- **Future:** Consider signed cookies for private video access

## Integration with MVP Goals

**Alignment:** ✅ Excellent

- Closes Issue #12 (MVP video serving migration)
- Reduces infrastructure costs (Vercel → R2)
- Improves scalability for MVP validation phase
- Maintains backward compatibility (local blob URLs still work)

## Recommendations

### Immediate (Before Next Deploy)

1. **Add Backend Tests:**
```python
# backend/tests/test_r2_storage.py
def test_get_object_url_with_public_base():
    """Test that public URL is preferred when configured."""
    pass

def test_get_object_url_fallback_to_presigned():
    """Test fallback to presigned URL when no public base."""
    pass
```

2. **Update Deployment Docs:**
   - Add `R2_PUBLIC_BASE_URL` to environment variable checklist
   - Document presigned URL expiration trade-offs
   - Add R2 bucket CORS configuration steps

3. **Increase Presigned Expiration:**
   - Change default from 3600s (1 hour) to 86400s (24 hours)
   - Or make it configurable per environment

### Future Enhancements

1. **Pydantic Response Models:**
   - Migrate `AnalysisResponse` to use Pydantic's `@dataclass`
   - Leverage FastAPI's automatic validation and serialization

2. **URL Refresh Mechanism:**
   - Frontend polling to refresh expiring presigned URLs
   - Or use public URLs in production

3. **Metrics Tracking:**
   - Track R2 bandwidth usage
   - Monitor presigned URL expiration issues

## Conclusion

**Overall Assessment:** ✅ **Excellent**

This is a well-executed feature addition that successfully migrates video serving from Vercel to R2. The implementation is clean, flexible, and follows best practices for cloud storage integration.

**Key Strengths:**
- Flexible URL strategy (public vs presigned)
- UUID-based naming prevents collisions
- Proper error handling and logging
- Good test coverage for frontend changes

**Minor Improvements Needed:**
- Add backend tests for `get_object_url()`
- Update deployment documentation
- Consider increasing presigned URL expiration

**Recommendation:** ✅ **Approve with minor follow-ups**

The commit is ready to merge. The recommended follow-ups (backend tests, deployment docs) can be addressed in subsequent commits without blocking this feature.
