Optional environment variables for the stack, one per line.

• KEY=VALUE — literal or with ${VAR} from the build environment
• KEY alone — same as KEY=${KEY} (copy from the build environment)

Blank lines and lines starting with # are ignored.

RABBITMQ_ERLANG_COOKIE
RABBITMQ_DEFAULT_USER
IMAGE_TAG=1.2.3

If Vault overlay is configured (Inherit or Manual), Vault values win for the same keys. When Vault is Not connected, only these step variables are sent (unless Merge with existing stack env is enabled on update — then Portainer’s current Env is the base and step keys overlay it).