Loading behaviour

Fuda applies configuration in a fixed sequence. Read this page when you combine several features.

1. Load configured dotenv files.
2. Render the source with WithTemplate, if configured.
3. Apply WithOverrides to the rendered source.
4. Decode the resulting YAML or JSON into the target struct.
5. Process each field's env, refFrom or ref, default, and dsn tags.
6. Call SetDefaults() on matching structs, then validate the final target.

Field precedence

For an ordinary field, an environment value wins over a configuration-file value. The file value wins over a default. Fuda preserves explicit zero values such as 0, false, and "" from the file. YAML null behaves as absent for default handling.

refFrom runs before its fallback ref tag when a field is still zero. A reference can provide a value before Fuda considers a default.

dsn runs after the other field tags. Declare values a DSN needs before the DSN field.

Setter and validation

Fuda processes nested fields before it calls SetDefaults() on the containing struct. Validation runs last, so it observes file values, environment overrides, references, defaults, DSNs, and dynamic defaults.

Next step

Handle loading errors.