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Configuration Lifecycle

From JSON to evaluation: how configuration flows through the validated boundary and into the active snapshot.

The lifecycle​

1) JSON payload arrives​

val json = fetchConfig()

2) Parse and validate​

when (val result = ConfigurationSnapshotCodec.decode(json)) {
    is ParseResult.Success -> AppFeatures.load(result.value)
    is ParseResult.Failure -> logError(result.error.message)
}

  • Guarantee: Invalid JSON never becomes a Configuration.

  • Mechanism: ParseResult makes success vs failure explicit at the boundary.

  • Boundary: Semantic correctness is not validated.

3) Atomic load​

Namespace.load(...) swaps the configuration snapshot atomically. Readers see either the old or new snapshot.

4) Evaluation reads the snapshot​

Evaluations are lock-free and read a snapshot at a single point in time.

Precondition: features must be registered​

Ensure your Namespace objects are initialized before parsing JSON.

val _ = AppFeatures

If JSON references a feature that is not registered, parsing fails with ParseError.FeatureNotFound.

Rollback support​

val success = AppFeatures.rollback(steps = 1)

Next steps​