# atmos.vendor

The `atmos.vendor` function runs `atmos vendor` through the current Atmos executable. Use it to pull, verify,
update, and inspect vendored components and stack dependencies from automation.

## Usage

```python
atmos.vendor(
    *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.vendor("pull")` runs `atmos vendor pull`.

| Subcommand | Purpose |
| --- | --- |
| [`pull`](/cli/commands/vendor/pull) | Pull vendored components and stack dependencies. |
| [`update`](/cli/commands/vendor/vendor-update) | Update vendored component versions to the latest allowed release. |
| [`verify`](/cli/commands/vendor/vendor-verify) | Verify vendored files match `vendor.lock.yaml`. |
| [`diff`](/cli/commands/vendor/vendor-diff) | Show the Git diff between two versions of a vendored component. |
| [`get`](/cli/commands/vendor/vendor-get) | Read the pinned version of a vendored component. |
| [`set`](/cli/commands/vendor/vendor-set) | Set the pinned version of a vendored component. |
| [`clean`](/cli/commands/vendor/vendor-clean) | Remove lock-owned vendored files. |
| `list` | List vendor configurations. |
| `config` | Read, edit, and list raw vendor manifest configuration. |

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

## Arguments

- **`*positionals`**

  (Optional) Strings placed on the command line right after `vendor`, in order: the subcommand and its
  positional arguments. 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 `"component"`
  becomes `--component`, and registered shorthands resolve to their long form.
- **`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

### Pull one component

```python
atmos.vendor("pull", flags = {"component": "vpc", "stack": "dev"})
```

This runs `atmos vendor pull --component=vpc --stack=dev`.

### Fail a pipeline when vendored files drift

```python
result = atmos.vendor("verify", output = "capture", check = False)
if result.exit_code != 0:
    fail("Vendored files do not match vendor.lock.yaml:\n" + result.stderr)
ui.success("Vendored files match the lock file.")
```

### Check for available updates

```python
updates = atmos.vendor("update", flags = {"check": True, "format": "json"}, output = "capture")
print(updates.stdout)
```

## Related

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