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Variables and secrets

Configuration for your app, given to it as environment variables.

Setting them

Open the app and go to Variables. A name may use letters, digits and underscores, and must not start with a digit: these are the names every shell and runtime can read.

Plain variables and secrets

• A plain variable is stored as it is and shown on the page. Saving one rolls out a new release of the app with it.
• A secret is encrypted with AES-256 before it is stored, and its value is never shown again. Use secrets for passwords, API keys and tokens. Saving or deleting one takes effect within seconds: the app restarts with it, without a new release.

Releases and rollback

Every release keeps the plain variables it ran with. Rolling back restores them exactly. Secrets are not kept in history, only their names: a release you roll back to runs with your secrets as they are now. If it used a secret you have since deleted, the rollback is refused until you add that secret back.