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

# Connect Cerebras inference to Bolna voice agents

> Use Cerebras Shared or Dedicated Inference for thousands of tokens per second in a Bolna voice agent. Model IDs, context limits by tier and setup steps.

[Cerebras](https://www.cerebras.ai) runs models on its wafer-scale hardware and is built for raw generation speed. Its model catalog lists `gpt-oss-120b` at around 3,000 tokens per second. On a voice call, fast generation means the full reply is ready almost as soon as the first token arrives, which helps longer answers and agents that call tools mid-turn.

The trade-off is a short catalog. Shared Inference offers a small set of models. More model families are available through Dedicated Inference.

***

## Models on Shared Inference

| Model ID | Parameters | Context (free / paid) | Speed |
| - | - | - | - |
| `gpt-oss-120b` | 120B | 65k / 131k | \~3,000 tokens/s |
| `qwen-3.8-27b` | 27B | 64k / 128k | \~1,850 tokens/s |

Values are from the Cerebras [model catalog](https://inference-docs.cerebras.ai/models/overview) at the time of writing; check it for the current list.

<Note>
  The context window is smaller on the free trial than on paid tiers. A long system prompt plus a long call can hit the free-tier limit before it hits the paid one.
</Note>

***

## Set up Cerebras

<Steps>
  <Step title="Create an API key in the Cloud Console">
    Sign in to the [Cerebras Cloud Console](https://cloud.cerebras.ai) and open **API Keys** in the left navigation. Create a key.
  </Step>

  <Step title="Try the model in the playground">
    The Cloud Console playground works without a key. Paste your agent's system prompt and a few caller lines to check tone and length before you wire it up.
  </Step>

  <Step title="Choose Cerebras in Bolna">
    Open **Settings → Integrations → LLM → Custom LLM → Add model**, or choose **+ Add custom LLM** in an agent's **LLM Provider** dropdown. Select **Cerebras**.

    <Frame caption="Cerebras selected in the Add custom model dialog">
      <img src="https://mintcdn.com/bolna-54a2d4fe/0EXypen329Eb5XE2/images/custom-llm/providers/cerebras-selected.png?fit=max&auto=format&n=0EXypen329Eb5XE2&q=85&s=395fde6ac532d3391f6adcc406512764" alt="Bolna Add custom model dialog with Cerebras selected and api.cerebras.ai shown as the endpoint placeholder" width="1024" height="1140" data-path="images/custom-llm/providers/cerebras-selected.png" />
    </Frame>
  </Step>

  <Step title="Register the model">
    <Tabs>
      <Tab title="Dashboard">
        * **Model name**: an exact Shared Inference model ID such as `gpt-oss-120b`. For Dedicated Inference, use your **endpoint ID** instead.
        * **Endpoint URL**: `https://api.cerebras.ai/v1`
        * **API key**: the key from the Cloud Console
        * **Family**: for example `gpt-oss` or `qwen`

        <Frame caption="Cerebras with gpt-oss-120b">
          <img src="https://mintcdn.com/bolna-54a2d4fe/aV72vktown5Rn3f1/images/custom-llm/providers/cerebras-filled.png?fit=max&auto=format&n=aV72vktown5Rn3f1&q=85&s=0e2266c7d4d0550d64409ab8ecff7d1b" alt="Add custom model dialog with Cerebras selected, model gpt-oss-120b, endpoint api.cerebras.ai/v1, masked key and family gpt-oss" width="1024" height="1092" data-path="images/custom-llm/providers/cerebras-filled.png" />
        </Frame>
      </Tab>

      <Tab title="API">
        ```bash theme={"system"}
        curl --request POST \
          --url https://api.bolna.ai/user/model/custom \
          --header 'Authorization: Bearer <BOLNA_API_KEY>' \
          --header 'Content-Type: application/json' \
          --data '{
            "custom_model_name": "gpt-oss-120b",
            "custom_model_url": "https://api.cerebras.ai/v1",
            "custom_model_key": "<CEREBRAS_API_KEY>",
            "custom_model_family": "gpt-oss"
          }'
        ```
      </Tab>
    </Tabs>
  </Step>

  <Step title="Use it on an agent">
    Choose **custom** on the agent's **Intelligence** tab, pick the Cerebras model, then save.
  </Step>
</Steps>

***

## Shared vs Dedicated Inference

With Shared Inference, the `model` field is a catalog model ID and limits depend on your tier (Free Trial or Pay as You Go). With [Dedicated Inference](https://inference-docs.cerebras.ai/dedicated/overview), the `model` field is your **stable endpoint ID**, which routes to whichever deployment is active. Because Bolna sends the registered model name as `model`, register a dedicated endpoint with its endpoint ID as the model name. You can then roll out a new deployment behind the same ID without touching your agents.

***

## Troubleshooting

<AccordionGroup>
  <Accordion title="429 rate limit errors">
    Shared Inference enforces per-tier request and token limits. Check your limits in the Cloud Console, move to Pay as You Go, or ask Cerebras about Dedicated Inference for sustained call volume.
  </Accordion>

  <Accordion title="Context length exceeded late in long calls">
    The free tier has the smaller context window. Shorten the system prompt, or upgrade for the full context length.
  </Accordion>

  <Accordion title="Model not found">
    Model IDs are short and exact, for example `gpt-oss-120b`, with no organisation prefix. Copy them from the catalog.
  </Accordion>

  <Accordion title="404 on chat completions">
    Use exactly `https://api.cerebras.ai/v1` as the endpoint URL. Bolna appends `/chat/completions` itself.
  </Accordion>
</AccordionGroup>

***

## Related

* [Custom LLM inference](/docs/custom-llm-inference)
* [Groq](/docs/custom-llm-inference/groq): another provider built for low-latency inference
* [Intelligence Tab](/docs/agent-setup/llm-tab)


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