How to merge json feature flag configs with override support
- Step 1Export base flag config — Export the default/base flag state from your feature flag platform. This is the fallback config that applies when no environment or segment override matches.
- Step 2Add environment overrides — Add the environment-specific override config as the second merge input. This overrides only the flags that have environment-specific values.
- Step 3Add segment overrides (optional) — Add user-segment or percentage-rollout overrides as the final merge input. These have the highest priority and override both base and environment values.
- Step 4Review the effective flag state — The merged output shows the effective flag state for the specified context. Use this to verify expected flag values in test fixtures or to diagnose unexpected flag behavior.
Frequently asked questions
How do flag platforms handle false overrides vs missing overrides?+
Most flag platforms distinguish between an override that is explicitly false (the flag is overridden to disabled) and a missing override (the flag falls back to the default). In JSON merge semantics, both present-false and missing are different: present-false overrides the base value to false, while missing allows the base value to pass through. Verify your merge logic handles both cases correctly.
Can I use this to create test fixtures that mock a specific flag state?+
Yes. Merge the layers for the target test context and copy the resulting JSON as your test fixture. Inject the merged config into your flag client's mock provider so tests get predictable, environment-independent flag values.
Are flag targeting rules transmitted to JAD Apps?+
No. Merging runs entirely in your browser. Feature flag configurations and targeting rules are never transmitted to JAD Apps servers.
Privacy first
Conversion runs locally in your browser. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.