Template format error: Unresolved resource dependencies in the Resources block of the template

Error Message

“The CloudFormation template is invalid: Template format error: Unresolved resource dependencies [ApiGatewayRestApi] in the Resources block of the template”

Problem

When you define a resource in your serverless.yml, you can reference an attribute of another resource dynamically.

This error happens when the referenced resource cannot be found.

Solution

Ensure you are referring to the logical ID of the resource. For example, if you define an S3 bucket in your resources:

...

resources:
  Resources:
    S3Bucket:
      Type: AWS::S3::Bucket
      Properties:
        BucketName: my-bucket

...

You can reference the name of the bucket with Ref: S3Bucket. Do not use the physical ID, Ref: my-bucket.