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

# Models chart

SambaStack keeps model definitions separate from platform infrastructure. The **models chart** (`sambastack-models`) is the Helm release that deploys the models, bundles, and PEFs your cluster serves, and it is installed alongside the infrastructure charts rather than bundled into them.

Because the model chart is in a separate release from the platform infrastructure charts, you can update which models you serve without touching the platform, and pin the two to different compatible versions when you need to.

<Warning>
  When you pin the models chart and the infra chart to different versions, make sure the two are compatible. SambaNova publishes the compatible version pairs.
</Warning>

## Chart layout

A SambaStack deployment is three Helm releases, installed in this order:

| Order | Release             | What it provides                                                               |
| :---- | :------------------ | :----------------------------------------------------------------------------- |
| 1     | `sambastack-base`   | Cluster prerequisites                                                          |
| 2     | `sambastack`        | The platform: operators, routing, gateway, and UI                              |
| 3     | `sambastack-models` | The model catalog: `Model`, `ModelProfile`, `ModelBundle`, and `Pef` resources |

<Note>
  `sambastack-base` → `sambastack` → `sambastack-models` is the recommended install order.
</Note>

For the commands, see [Quickstart - on-prem](/docs/en/v2.0.2/sambastack/getting-started/on-prem). On hosted deployments the sambastack-installer deploys all three releases for you, in the same order — see [Quickstart - hosted](/docs/en/v2.0.2/sambastack/getting-started/hosted).

## Where its values live

The models chart takes its own values, separate from `sambastack.yaml`:

| Deployment type | Location                                                                                                 |
| :-------------- | :------------------------------------------------------------------------------------------------------- |
| **On-prem**     | A values file passed to `helm upgrade --install sambastack-models`, with the keys at the top level       |
| **Hosted**      | The `models.yaml` section of the installer ConfigMap, which the installer passes verbatim to the release |

## Selecting and deploying bundles

Two keys control what the chart serves, and they do different jobs:

* **`modelBundleSpecs`** selects which of the `ModelBundle` resources provided with SambaStack to render. Omit it, or leave it empty, to render all of them. Rendering a bundle makes it available for deployment, but does not deploy it.
* **`modelDeploymentSpecs`** deploys bundles, with replica-group configuration.

```yaml theme={}
modelBundleSpecs:
  - name: cd-dyt-gpt-oss-120b-8-32-64-128k
modelDeploymentSpecs:
  - name: cd-dyt-gpt-oss-120b-8-32-64-128k
    groups:
      - name: default
        minReplicas: 1
        qosList: [web, free]
```

<Note>
  `modelDeploymentSpecs[].name` is used as both the `ModelDeployment` name and its `spec.bundle`, so it must match a `ModelBundle` name. Duplicate names fail the Helm render.
</Note>

For the bundles SambaNova provides, see [Supported models and bundles](/docs/en/v2.0.2/sambastack/service-administration/model-deployment/supported-models-and-bundles). For the QoS tags in `qosList`, see [Service tiers](/docs/en/v2.0.2/sambastack/service-administration/platform-admin/usergroup-management#service-tiers).

## Configuration reference

These are the models chart's own values. Hosted, they go in the `models.yaml` section of the installer ConfigMap. On-prem, they go at the top level of the values file passed to the release.

| Parameter                                     | Type    | Description                                                                                                                                                                       |
| :-------------------------------------------- | :------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `modelBundleSpecs[]`                          | list    | Selects which of the `ModelBundle` resources provided with SambaStack to render. Omit it, or leave it empty, to render all of them. Rendering a `ModelBundle` does not deploy it. |
| `modelDeploymentSpecs[]`                      | list    | Deploys bundles, with replica-group configuration.                                                                                                                                |
| `modelDeploymentSpecs[].name`                 | string  | Bundle name to deploy. Used as both the `ModelDeployment` name and its `spec.bundle`, so it must match a `ModelBundle` name. Duplicate names fail the Helm render.                |
| `modelDeploymentSpecs[].groups[].name`        | string  | Routing/capacity group name                                                                                                                                                       |
| `modelDeploymentSpecs[].groups[].minReplicas` | integer | Minimum engines for the group                                                                                                                                                     |
| `modelDeploymentSpecs[].groups[].qosList[]`   | list    | QoS tags (e.g., `web`, `free`, `pro`)                                                                                                                                             |
| `global.substitutions`                        | object  | String substitutions applied to the rendered model resources. Only needed for NFS or air-gapped deployments.                                                                      |

See [Service tiers](/docs/en/v2.0.2/sambastack/service-administration/platform-admin/usergroup-management#service-tiers) for details on QoS tags.

## Artifact locations

The models chart applies string substitutions to the resources it renders. NFS and air-gapped deployments set `global.substitutions` in the models chart values:

```yaml theme={}
global:
  substitutions:
    gs://<SAMBASTACK_ARTIFACTS_BUCKET>: nfs:///nfsdata
```

## Related resources

<CardGroup cols={2}>
  <Card icon="rocket" href="/docs/en/sambastack/resources/sambastack-yaml" title="SambaStack.yaml reference">
    Every configuration key, and which chart each one belongs to
  </Card>

  <Card icon="cube" href="/docs/en/sambastack/service-administration/model-deployment/bundles-v3" title="Migrating bundle configuration">
    The resource model behind the bundles this chart deploys, and how to migrate to it
  </Card>

  <Card icon="layer-group" href="/docs/en/sambastack/service-administration/model-deployment/deploying-model-bundles" title="Deploying models and bundles">
    Authoring the custom resources directly
  </Card>

  <Card icon="compress" href="/docs/en/sambastack/service-administration/model-deployment/deploy-custom-checkpoints" title="Deploying custom checkpoints">
    The Model resource reference, and serving your own checkpoints
  </Card>
</CardGroup>