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

# Anam + Cartesia

> Use a Cartesia Sonic TTS voice in an Anam interactive avatar session

<Check>Last verified: 2026-06-11</Check>

## Overview

Use this integration to run an [Anam](https://anam.ai/docs) interactive avatar with a [Cartesia Sonic TTS](/build-with-cartesia/tts-models/latest) voice. Anam handles the avatar session, WebRTC stream, and rendering, while a Cartesia voice provides the speech output.

## Prerequisites

* Anam API key (`ANAM_API_KEY`) from the [Anam Lab API keys page](https://lab.anam.ai/api-keys)
* Node.js 18+ for the backend token endpoint
* A frontend app that can render the Anam JavaScript SDK ([production guide](https://anam.ai/docs/javascript-sdk/production))

This flow does not require a Cartesia API key in your app. Anam uses the saved Cartesia voice attached to the Anam `voiceId`.

## Installation

```bash theme={null}
npm install express @anam-ai/js-sdk
```

Set your Node project to ESM so the backend and frontend snippets work as written (`import` syntax):

```json theme={null}
{
  "type": "module"
}
```

## Quick start

Create an Anam session token with a Cartesia voice, then initialize the avatar in the browser with the returned session token.

### 1) Backend: create an Anam session token

```javascript theme={null}
import express from "express";

const app = express();
app.use(express.json());

const requiredEnvVars = ["ANAM_API_KEY"];

for (const name of requiredEnvVars) {
  if (!process.env[name]) {
    throw new Error(`${name} is required`);
  }
}

// Swap these for another avatar, Cartesia voice, or LLM from Anam Lab.
const avatarId = "071b0286-4cce-4808-bee2-e642f1062de3"; // Liv
const voiceId = "c48c4dd9-5050-11f1-9076-5e955d484d11"; // Siobhan - Warm Welcomer
const llmId = "a7cf662c-2ace-4de1-a21e-ef0fbf144bb7"; // GPT OSS 120B

app.post("/api/anam-session", async (req, res) => {
  const sessionTokenResponse = await fetch("https://api.anam.ai/v1/auth/session-token", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.ANAM_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      personaConfig: {
        name: "Cartesia voice avatar",
        avatarId,
        voiceId,
        llmId,
        systemPrompt: "You are a concise voice assistant. Keep responses brief.",
        voiceGenerationOptions: {
          speed: 1,
          volume: 1,
          emotion: "content",
        },
      },
    }),
  });

  if (!sessionTokenResponse.ok) {
    const errorBody = await sessionTokenResponse.text();
    return res.status(502).json({
      error: "Failed to create Anam session token",
      detail: errorBody,
    });
  }

  const session = await sessionTokenResponse.json();
  return res.json(session); // { sessionToken }
});

app.listen(3000);
```

The `voiceId` value is an Anam voice ID for a Cartesia voice, not a raw Cartesia provider voice ID. To find another one with the API, call the [list voices endpoint](https://anam.ai/docs/api-reference/voices/list-voices) and choose a voice where `provider` is `CARTESIA`. As of writing, Anam Lab lists 304 stock Cartesia voices.

```bash theme={null}
curl "https://api.anam.ai/v1/voices?perPage=100&search=voice-name" \
  -H "Authorization: Bearer $ANAM_API_KEY"
```

You can also clone a Cartesia voice or import a Cartesia provider voice in Lab. When importing, set the provider voice ID and a default provider model such as `sonic-3.5`. Lab validates the voice before saving it as an Anam voice.

### 2) Frontend: initialize Anam with session token

Add a video element and a start button in your page HTML:

```html theme={null}
<video id="anam-video" autoplay playsinline></video>
<button id="start-avatar" type="button">Start avatar</button>
```

The sample below uses a browser module entry file. Wrap the call in an async function if your frontend is not a module.

```typescript theme={null}
import { createClient } from "@anam-ai/js-sdk";

let anamClient: ReturnType<typeof createClient> | undefined;

async function startAvatar() {
  const response = await fetch("/api/anam-session", { method: "POST" });

  if (!response.ok) {
    throw new Error("Failed to create Anam session");
  }

  const { sessionToken } = await response.json();
  anamClient = createClient(sessionToken);

  await anamClient.streamToVideoElement("anam-video");
}

document.querySelector<HTMLButtonElement>("#start-avatar")?.addEventListener("click", () => {
  startAvatar().catch((error) => {
    console.error(error);
  });
});
```

When the session starts, the video element shows Liv speaking with the Siobhan Cartesia voice. Try asking a short question in the browser.

## Voice and performance options

Use `voiceGenerationOptions` on the session token request to set Cartesia voice generation controls for the session, such as `speed`, `volume`, and `emotion`. See Anam's [voice configuration](https://anam.ai/docs/personas/voices/configuration) docs for supported values.

<Note>For advanced performance control, Anam can preserve Cartesia-supported inline cues in the transcript while also using the same cue names for avatar Director Notes where enabled. For example, Cartesia documents [speech control tags](/build-with-cartesia/capability-guides/ssml-tags); Anam can use a matching `laughter` cue to shift the avatar toward a playful visual style.</Note>

## Resources

* [Anam JavaScript SDK production guide](https://anam.ai/docs/javascript-sdk/production)
* [Anam create session token API](https://anam.ai/docs/api-reference/sessions/create-session-token)
* [Anam list voices API](https://anam.ai/docs/api-reference/voices/list-voices)
* [Anam custom voices guide](https://anam.ai/docs/personas/voices/custom-voices)
* [Cartesia volume, speed, and emotion controls](/build-with-cartesia/capability-guides/volume-speed-emotion)
* [Cartesia speech control tags](/build-with-cartesia/capability-guides/ssml-tags)