pydantic-multi-source-settings

To load Pydantic settings from multiple sources, define a BaseSettings class with env_prefix and env_file, then use a model_validator hook to fetch missing values from the remote service. This establishes a clear precedence: environment variables override remote defaults, with .env as a fallback.

The best way to maintain cached Pydantic settings is to use an lru_cache-wrapped getter function. Calling get_settings() provides a singleton instance of your Settings model, ensuring consistent configuration throughout the app lifecycle without redundant initializations.

Yes, Pydantic BaseSettings supports fetching missing values from remote config services like Apollo or Consul. You implement a loader within a model_validator hook to pull remote values during startup, integrating them with local environment variables and .env file settings.

You configure case_sensitive settings and env_prefix directly within your BaseSettings class definition. This ensures environment variables and .env file keys are matched accurately according to your desired case sensitivity and naming conventions during the multi-source configuration consolidation.

If an environment variable does not override a remote configuration value, the multi-source precedence order may be misconfigured. The correct hierarchy ensures environment variables take priority, overriding remote defaults, while the .env file acts as a fallback for missing values.