Feature request: add --express flag to sam delete #9115

Description

PR #9106 adds --express/--no-express support to sam deploy and sam sync for CloudFormation Express mode, but sam delete does not expose the same flag.

As noted in PR #9106 comment:

Usage: sam delete [OPTIONS]
Try 'sam delete -h' for help.

Error: No such option: --express

For teams using express mode during development, delete is part of the same iteration loop as deploy/sync. Without express support on sam delete, teardown remains on the slower standard path even when stacks were created or updated with --express.

Use Case

During fast development iteration, developers want to tear down stacks quickly without waiting for full resource stabilization and cleanup. CloudFormation Express mode supports this for delete operations:

aws cloudformation delete-stack --stack-name my-stack \
    --deployment-config '{"Mode": "EXPRESS"}'

See the CloudFormation Express mode documentation and the delete-stack API reference.

Proposed Behavior

Add --express/--no-express to sam delete, consistent with sam deploy and sam sync:

• When enabled, pass DeploymentConfig={"Mode": "EXPRESS"} to the CloudFormation DeleteStack API
• Default: off (for backwards compatibility)
• Persist to samconfig.toml via --save-params as express = true/false
• After delete completes in express mode, surface a message that some resources may still be removing in the background (similar to deploy/sync)

Current Workaround

Use the AWS CLI directly:

aws cloudformation delete-stack --stack-name <stack-name> \
    --deployment-config '{"Mode": "EXPRESS"}'

Note: this bypasses sam delete's guided cleanup of S3 artifacts, ECR images, and companion stacks.

Related

• feat: add --express flag to sam deploy and sam sync #9106 (adds --express to sam deploy and sam sync)
• Announcement: sam deploy and sam sync now support CloudFormation Express mode #9110 (announcement for express mode support in deploy/sync)