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

# Available LLMs

> Built-in language models you can use with Anam personas

Every persona needs a language model to power its conversations. Anam provides several built-in LLMs you can use without any additional setup — just reference the model's ID in your persona configuration.

## Built-in models

| LLM ID                                 | Model         | Best for                                                                             |
| -------------------------------------- | ------------- | ------------------------------------------------------------------------------------ |
| `a7cf662c-2ace-4de1-a21e-ef0fbf144bb7` | GPT OSS 120B  | Recommended for most projects                                                        |
| `ANAM_LLAMA_v3_3_70B_V1`               | Llama 3.3 70B | Great conversationalist, very fast. Not recommended for tool calls or knowledge base |
| `b4f89001-9638-4879-a9c3-02cc9f9f2004` | GPT 4.1       | Slow but capable all-rounder                                                         |

## Using a built-in LLM

Set the `llmId` field in your persona configuration to the ID of the model you want to use:

```javascript theme={"system"}
const personaConfig = {
  name: "Cara",
  avatarId: "30fa96d0-26c4-4e55-94a0-517025942e18",
  voiceId: "6bfbe25a-979d-40f3-a92b-5394170af54b",
  llmId: "a7cf662c-2ace-4de1-a21e-ef0fbf144bb7",
  systemPrompt: "You are Cara, a helpful customer service representative.",
};
```

You can also select a model from the dropdown in [Anam Lab](https://lab.anam.ai) when creating or editing a persona.

## Choosing a model

For most use cases, **GPT OSS 120B** is a good starting point — it's fast, has strong reasoning, and handles [tools](/concepts/tools) reliably. Choose **Llama 3.3 70B** for the most natural conversational feel when you don't need tool calling or a knowledge base. Choose **GPT 4.1** when you need a capable all-rounder and can tolerate higher latency.

<Note>
  Older `llmId`s previously listed here — including GPT-4.1 Mini (`0934d97d-0c3a-4f33-91b0-5e136a0ef466`), Gemini 3 Flash Preview (`27cbd128-f1e6-4b67-8ab3-9123659be08c`), Gemini 2.5 Flash (`9d8900ee-257d-4401-8817-ba9c835e9d36`), and Kimi k2 (`88190a76-3e87-4935-ab39-f4f73038815a`) — continue to work for existing configurations, but are no longer recommended for new projects.
</Note>

## Greeting behavior

When using a built-in LLM, the persona greets the user with an opening message when the session starts. By default the greeting is generated from the system prompt, but you can set the exact line yourself or skip the greeting altogether.

### Set a custom first message

Use `initialMessage` to set the exact line the persona speaks at the start of the session, instead of letting the LLM generate one from the system prompt:

```javascript theme={"system"}
const personaConfig = {
  name: "Cara",
  avatarId: "30fa96d0-26c4-4e55-94a0-517025942e18",
  voiceId: "6bfbe25a-979d-40f3-a92b-5394170af54b",
  llmId: "0934d97d-0c3a-4f33-91b0-5e136a0ef466",
  systemPrompt: "You are Cara, a helpful customer service representative.",
  initialMessage: "Hi, I'm Cara from customer support. What can I help you with today?",
};
```

If `initialMessage` is omitted, empty, or whitespace-only, the persona falls back to a greeting generated from the system prompt.

You can also set the first message from the **Prompt** tab in [Anam Lab](https://lab.anam.ai) — leave the field blank to keep the auto-generated greeting.

### Skip the greeting

To have the persona wait for the user to speak first, set `skipGreeting` to `true`:

```javascript theme={"system"}
const personaConfig = {
  name: "Cara",
  avatarId: "30fa96d0-26c4-4e55-94a0-517025942e18",
  voiceId: "6bfbe25a-979d-40f3-a92b-5394170af54b",
  llmId: "a7cf662c-2ace-4de1-a21e-ef0fbf144bb7",
  systemPrompt: "You are Cara, a helpful customer service representative.",
  skipGreeting: true,
};
```

This is useful when you want the user to initiate the conversation, or when the persona is responding to an event rather than starting a dialogue. When `skipGreeting` is `true`, any `initialMessage` value is ignored.

### Protect the greeting from interruptions

By default, the user can interrupt the greeting as soon as the persona starts speaking. To make the greeting play through to completion, set `uninterruptibleGreeting` to `true`:

```javascript theme={"system"}
const personaConfig = {
  name: "Cara",
  avatarId: "30fa96d0-26c4-4e55-94a0-517025942e18",
  voiceId: "6bfbe25a-979d-40f3-a92b-5394170af54b",
  llmId: "0934d97d-0c3a-4f33-91b0-5e136a0ef466",
  systemPrompt: "You are Cara, a helpful customer service representative.",
  uninterruptibleGreeting: true,
};
```

Use this when the greeting carries information the user needs to hear in full, such as a regulatory disclosure, a privacy notice, or instructions that frame the rest of the conversation. After the greeting finishes, normal interruption behavior resumes.

`uninterruptibleGreeting` has no effect when `skipGreeting` is `true`.

## Bring your own LLM

If the built-in models don't fit your needs, you can connect your own:

* **[Server-side custom LLMs](/concepts/custom-llms)** — Register your model with Anam and we call it from our servers, keeping latency low.
* **[Client-side custom LLMs](/examples/custom-llm)** — Handle LLM calls yourself in your client code using `CUSTOMER_CLIENT_V1` as the LLM ID.
* **[LiveKit](/third-party-integrations/livekit)** — Use Anam as a face layer in your existing LiveKit agent pipeline with any LLM.