# Phase 7 Wave 2 Summary: Backend Config Refactoring (07-02)

**Completed:** 2026-04-23
**Status:** [COMPLETED]
**Commits:** ae61fa63, 28cdc900, 938fd2da, 225972b8

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## Accomplishments

1. **backend/config_loader.py Refactored**
   - Implemented YAML parsing using PyYAML
   - Enforced D-06 load order: System Env Vars > `config/backend.yaml` > `config/secrets.yaml` > Defaults
   - Added robust validation for required fields (JWT_SECRET_KEY, primary_ai_provider)
   - Masked sensitive values in logs

2. **backend/config_manager.py Updated**
   - Refactored to handle YAML file operations (`read_config`, `update_config`)
   - Removed legacy `.env` file manipulation logic

3. **backend/main.py Updated**
   - Switched from direct `os.environ` access to the centralized `get_config()` dict
   - Removed `load_dotenv()` and `inventory.env` references

4. **backend/entrypoint.sh Updated**
   - Updated to document the new YAML configuration structure
   - Added safety checks for the existence of `backend.yaml`

5. **Additional Backend Files Cleaned Up**
   - Refactored `backend/ai_vision.py`, `backend/check_models.py`, `backend/ai/gemini.py`, and `backend/ai/claude.py` to use `config_loader`
   - Completely removed `python-dotenv` dependency from backend

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## Technical Details

- **Load Order (D-06):** Env Vars override YAML, YAML overrides Defaults.
- **Deprecation (D-04):** `inventory.env` is no longer used by the backend application logic.
- **Security:** Sensitive configuration values are masked in application logs to prevent data leaks.

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## Verification

- [x] All updated Python files passed `py_compile` checks
- [x] No `load_dotenv()` or `inventory.env` references remain in backend code
- [x] Configuration loading logs which source was used for each value
- [x] Environment variables correctly override YAML values in `config_loader.py`