Environment variables

Open a service → Env vars. Values are write-only: once saved they are never shown again, so keep a copy of anything you need.

• Saving a key that already exists replaces its value.
• Changes apply after a redeploy (GitHub apps) or restart (one-click apps).
• Names may contain letters, digits and _, and must not start with a digit.

One-click apps come with generated variables (for example passwords). Changing them can break the app — only edit them if you know what they do.