# 002 Config From YAML and Env

Context
- The service needs readable project configuration and safe handling of sensitive values.
- The final configuration object should be easy to inject and test.

Decision
- Keep non-sensitive defaults in YAML files under `config/`.
- Read sensitive values only from environment variables.
- Merge YAML and env sources into one `AppConfig` dataclass tree in `adapter/config/`.
- Keep configuration parsing and validation outside `domain/` and `usecase/`.

Consequences
- Local configuration remains simple to inspect and version.
- Secrets stay out of committed files.
- Inner layers depend on typed config data, not on env or YAML readers.