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Feature Manifest Language errors (mobile only)


Want more info on the Feature Manifest Language? Check out the documentation here

For non-desktop applications, the Feature Manifest Language (FML) is used to surface errors when we are configuring our branches. This is particularly helpful for deeply nested features, which can be difficult to configure on the Branches page.

You can see that the save button validation has given us usable FML errors, including the line/col number that the error occurs at:

The FML generates errors based on the feature you are using, the application, and the channel. Changing the channel on your experiment may result in different FML errors, since there may be differences between the feature manifests for each channel.


When configuring your branches for a desktop experiment, you will see autocomplete as you type, as well as JSON linting. FML errors are not present on desktop, since desktop does not use the Feature Manifest Language.