The Stack must exist in CloudFormation before the config using this Lookup begins processing to successfully get a value. This means that it must have been deployed using another Runway module, deployed from a config that is run before the one using it, deployed manually, or deployed in the same config using required/required_by to specify a dependency between the Stacks.

Query Syntax

<stack-name>.<output-name>[::<arg>=<arg-val>, ...]

Retrieve a value from CloudFormation Stack Outputs.

When specifying the output name, be sure to use the Logical ID of the output; not the Export.Name.

If the Lookup is unable to find a CloudFormation Stack Output matching the provided query, the default value is returned or an exception is raised to show why the value could be be resolved (e.g. Stack does not exist or output does not exist on the Stack).

New in version 1.11.0.


This Lookup supports all Common Lookup Arguments.


namespace: example

  - ...
      VpcId: ${cfn ${namespace}-vpc.Id}

Given the above config file, the lookup will get the value of the Output named Id from Stack example-vpc.