We’ve added a new eval object to all variable evaluations, making it easier than ever to debug and understand why a specific value was returned for a user.
Each Variable evaluation now includes:

reason – the primary reason a value was served (e.g. TARGETING_MATCH, DEFAULT, SPLIT, etc.)
details – optional context for why the match occurred
target_id – the rule or audience that matched, when applicable

These values are especially useful for debugging, QA, building custom logs and observability workflows.

⚠️ Heads up: the older evalReason field is now deprecated and will be removed in an upcoming release. Please update your SDK usage to rely on the new eval object instead.

Learn more about evaluation reasons in the docs: https://docs.devcycle.com/sdk/features#evaluation-reasons

DevCycle changelog

Variable Evaluation Reasons