# atmos.atlantis

The `atmos.atlantis` function runs `atmos atlantis` through the current Atmos executable. Use it to generate the
Atlantis repository configuration for your Atmos stacks and components from automation.

## Usage

```python
atmos.atlantis(
    *positionals,
    flags = {},
    args = [],
    working_directory = ...,
    env = ...,
    output = "stream",
    check = True,
)
```

## Subcommands

Pass the subcommand and any positional arguments as strings before the keyword arguments. The call
`atmos.atlantis("generate", "repo-config")` runs `atmos atlantis generate repo-config`.

| Subcommand | Purpose |
| --- | --- |
| `generate` | Generate Atlantis configuration files. |
| [`generate repo-config`](/cli/commands/atlantis/generate-repo-config) | Generate the repository configuration file that Atlantis needs to manage Terraform projects. |

See the [`atmos atlantis` command reference](/cli/commands/atlantis/usage) for the complete list of subcommands and
flags.

## Arguments

- **`*positionals`**

  (Optional) Strings placed on the command line right after `atlantis`, in order: the subcommand and its
  positional arguments, such as `"generate", "repo-config"`. Every value must be a string.
- **`flags`**

  (Optional) A dictionary of command-line options; see
  [flag translation](/functions/automation/atmos.run#flag-translation). A bare key such as
  `"config-template"` becomes `--config-template`. Other flags for `generate repo-config` include
  `--project-template`, `--affected-only`, `--stacks`, `--components`, and `--output-path`. Flags such as
  `--stacks` take a comma-separated string, so pass `"dev,prod"` rather than a list.
- **`args`**
  (Optional) A list or tuple of strings appended after the flags.
- **`working_directory`, `env`, `output`, `check`**

  (Optional) See [`atmos.run`](/functions/automation/atmos.run#arguments) for process options and defaults.

Options other than the positionals are keyword-only.

## Returns

A result with `stdout`, `stderr`, and `exit_code`. See [`atmos.run`](/functions/automation/atmos.run#returns) for output and error behavior.

## Examples

### Generate the configuration for selected stacks

```python
atmos.atlantis(
    "generate",
    "repo-config",
    flags = {
        "config-template": "config-1",
        "project-template": "project-1",
        "stacks": "tenant1-ue2-staging,tenant1-ue2-prod",
        "output-path": "atlantis.yaml",
    },
)
```

The template names refer to the Atlantis templates defined in `atmos.yaml`.

### Generate projects only for affected components

```python
atmos.atlantis(
    "generate",
    "repo-config",
    flags = {
        "config-template": "config-1",
        "project-template": "project-1",
        "affected-only": True,
        "ref": "refs/heads/main",
        "output-path": "atlantis.yaml",
    },
)
```

This limits the generated projects to the components that changed compared with the `main` branch.

## Related

- [`atmos.run`](/functions/automation/atmos.run) runs any Atmos command from an argument list.
- [`atmos atlantis`](/cli/commands/atlantis/usage) documents every subcommand and flag.
- [Atmos Automation Language](/automation/language) and the [script step](/steps/type/script#calling-atmos-commands)