---
title: Structured Logging Implementation Complete
type: note
permalink: development/structured-logging-implementation-complete-1
---

[{"text": "# Structured Logging - Implementation Complete\n\n## Date: December 2, 2025\n\n## Summary\nAdded production-ready structured logging with `structlog` to replace all `print()` statements.\n\n## Key Features\n- **JSON logs for production** (machine-readable, Cloud Logging compatible)\n- **Colored logs for development** (human-readable)\n- **Automatic request ID tracking** (UUID per request)\n- **Request context** (method, path, IP, user_agent)\n- **Duration tracking** (milliseconds)\n- **User ID placeholder** (ready for auth)\n\n## Files Changed\n1. `backend/pyproject.toml` - Added structlog==25.5.0\n2. `backend/src/kinemotion_backend/logging_config.py` - New logging config\n3. `backend/src/kinemotion_backend/middleware.py` - New request tracking middleware\n4. `backend/src/kinemotion_backend/app.py` - Replaced all print() with logger calls\n\n## Configuration\n\n**Development:**\n```bash\nLOG_LEVEL=INFO\nJSON_LOGS=false\n```\n\n**Production (Cloud Run):**\n```bash\nLOG_LEVEL=INFO\nJSON_LOGS=true\n```\n\n## Log Events Added\n- `request_started`, `request_completed`, `request_failed`\n- `r2_storage_initialized`, `r2_storage_not_configured`\n- `analyze_request_received`\n- `video_uploaded_to_r2`, `r2_upload_failed`\n- `video_analysis_completed`, `video_analysis_failed`\n- `results_uploaded_to_r2`, `r2_results_upload_failed`\n- `validation_error`\n- `temp_file_cleaned`, `temp_file_cleanup_failed`\n- `unhandled_exception`\n\n## Context Variables\n- `request_id` - Unique UUID per request (in X-Request-ID header)\n- `method` - HTTP method\n- `path` - Request path  \n- `client_ip` - Client IP\n- `user_id` - (Placeholder for future auth)\n\n## Testing\n✅ All 85 tests pass\n✅ Type checking passes (pyright strict)\n✅ Linting passes (ruff)\n\n## Next: Add Authentication\nWhen auth is added, bind user_id to context:\n```python\nstructlog.contextvars.bind_contextvars(user_id=extracted_user_id)\n```\n\nAll logs will automatically include user_id!\n\n## References\n- Structlog: https://www.structlog.org/\n- Cloud Logging: https://cloud.google.com/logging/docs/", "type": "text"}]
