> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mutagent.io/llms.txt
> Use this file to discover all available pages before exploring further.

# mutagent helix models

> List the models your Helix Cloud sessions can use, and set the default model a run uses when it names none.

Cloud sessions can use any model offered by the workspace's active
[LLM providers](/cli/commands/providers). A run that names no model uses the workspace default. With
no default set, the run is refused with HTTP 428 before any sandbox starts.

**Before you start:** [install the CLI](/cli/installation), [sign in](/cli/commands/login)
(`MUTAGENT_API_KEY=<key> mutagent login --json` for a coding agent), select the workspace with
`mutagent workspaces use <workspace-name>`, and add at least one
[LLM provider](/cli/commands/providers) to it.

## mutagent helix models

List the models cloud sessions can use, as `provider/model`. ★ marks the default.

```bash theme={null}
mutagent helix models --json
```

Pass one of these IDs to `mutagent helix --model`. An ID that is not in the list is refused with HTTP
422\. A line under the list names any LLM provider whose key Helix Cloud cannot use.

With `--json`, the output is `{ workspaceId, models, defaults, default, unmapped }`. Each entry in
`models` has an `id` to pass as `--model`. Pick IDs from `models[].id`; never invent one.

* `models` is empty: the workspace has no active LLM provider Helix can use. Add one with
  [mutagent providers add](/cli/commands/providers), or copy your local logins with
  `mutagent providers mirror`.
* `default` is `null`: runs without `--model` are refused with HTTP 428. Set a default below.
* `unmapped` lists LLM providers whose keys Helix Cloud cannot load into a sandbox.

## mutagent helix models default

Set the workspace default model. List more IDs after it as fallbacks; they are used in order when the
LLM provider of an earlier model has been deactivated. The command replaces the whole list.

```bash theme={null}
mutagent helix models default <provider/model> --json
mutagent helix models default <provider/model> <fallback-provider/model> --json
```

Success: exit code `0`, and `--json` prints the same shape as `mutagent helix models --json` after the
change, with your first ID in `default`. Every ID must appear in `mutagent helix models`; the server
refuses any other ID with HTTP 422 (exit 1).

| Flag | What it does |
| - | - |
| `--clear` | Remove the default and all fallbacks. Runs without `--model` are then refused with HTTP 428. |

`mutagent providers mirror` sets a default when the workspace has none. The cloud default does not
change your local Helix default.

Exit code `3` means you are not signed in or no workspace is selected, and `2` means the key expired
or is invalid. See [CLI errors](/cli/errors).


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