# atmos aws cloudformation stackset update

Update a StackSet’s template, parameters, and capabilities, then wait for the
update to reach its existing instances. This command does not add or remove instances.

> ⚠️ Experimental

## Usage

```shell
atmos aws cloudformation stackset update <component> --stack <stack> [options]
```

```shell
atmos aws cloudformation stackset update vpc -s plat-ue2-dev
```

Skip the interactive confirmation prompt:

```shell
atmos aws cloudformation stackset update vpc -s plat-ue2-dev --auto-approve
```

Disambiguate when the component declares more than one `kind: aws/stackset` target:

```shell
atmos aws cloudformation stackset update vpc -s plat-ue2-dev --target multi-account
```

Update StackSets for all or affected components in dependency order:

```shell
atmos aws cloudformation stackset update --all -s plat-ue2-dev
atmos aws cloudformation stackset update --affected --base origin/main
```

## Flags

- **`--stack`, `-s` (required for a single component)**
  Atmos stack. With 
  `--all`
  , 
  `--affected`
  , 
  `--tags`
  , or 
  `--labels`
  , this is an optional stack filter; omit it to select components across stacks.
- **`--target` (optional)**
  The 
  `kind: aws/stackset`
   provision target to use. Required when more than one is declared.
- **`--auto-approve` (optional)**
  Skip the interactive confirmation prompt. Without it, 
  `stackset update`
   prompts for confirmation on a TTY before updating the StackSet.

## Behavior

Atmos creates instances during [`stackset create`](/cli/commands/aws/cloudformation/stackset/create)
and has no command to add instances to an existing StackSet. To add instances later,
use the [AWS CloudFormation console or AWS CLI](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/stackinstances-create.html).

The `UpdateStackSet` operation is polled every 3 seconds until it reaches a
terminal status (`SUCCEEDED`/`FAILED`/`STOPPED`), and the command times out
after 30 minutes if it hasn't.

:::note
`stackset update` does not fire `before`/`after` hook events — only
[`apply`](/cli/commands/aws/cloudformation/apply),
[`diff`](/cli/commands/aws/cloudformation/diff),
[`delete`](/cli/commands/aws/cloudformation/delete),
[`drift detect`](/cli/commands/aws/cloudformation/drift/detect), and
[`drift describe`](/cli/commands/aws/cloudformation/drift/describe) do.
:::