> This page is for Voice APIs.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://dev.hume.ai/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://dev.hume.ai/_mcp/server.

# EVI Version

EVI 3 and EVI 4-mini are the currently supported versions of Hume’s Empathic Voice Interface. EVI 1 and EVI 2 reached end of support on
August 30, 2025. This guide explains how to set the EVI version in Chat and provides a migration path for
integrations using EVI 1 or EVI 2.

## How EVI version is applied

The EVI version is resolved from the Config you use to start a Chat.

* Provide a `config_id` when you start the Chat.
* The service loads that Config and reads its evi\_version.
* The Chat uses that version for its lifetime.

If you omit `config_id`, the Chat uses EVI 3 by default.

## Set the EVI version

The EVI version is set using the `evi_version` field in your
[Config](/docs/speech-to-speech-evi/configuration/build-a-configuration). The version associated with the
`config_id` you provide when starting a Chat determines which EVI version is used.

## Update an existing Config \[#update-an-existing-config]

**To change the version of an existing Config:**

1. Go to the [Configurations page](https://app.hume.ai/evi/configs).
2. Find your Config by name and click **Edit**.
3. Select a different version from the edit page.

![Configurations page](/_fern-img/f71a9bf47fabf374c17f8444faad3073bea7cc59351e1b1ad66ac575e42901ca.webp)![Config edit page](/_fern-img/938a0d873a76ef900599785a68c9b41db4bc791e75f004764039567bba733521.webp)

**You can also update the version directly in the EVI playground** by selecting a Config and changing the version in
the panel on the right.

![EVI playground](/_fern-img/0ecf09f32094867df15ad8e3e7c5875147ce41b9f7acb8e0d9309b8e07beaa81.webp)

#### [API Reference](/reference/speech-to-speech-evi/configs/create-config-version)

See our API reference for how to **update an EVI Config through the API.**

## EVI 4-mini guide

### Changes

1. **EVI 4-mini is multilingual**

   * **Impact**: EVI 4-mini supports the following languages: English, Japanese, Korean, Spanish, French, Portuguese, Italian, German, Russian, Hindi, Arabic.

   * **Action**: [Create a new voice](https://app.hume.ai/voices?category=my-voices) with a prompt in the language you'd like to use.

2. **Latency improvement**

   * **Impact**: The model latency improvement is \~100ms on each response.

This section details the changes required to migrate from EVI 3 to EVI 4-mini. If you are migrating from EVI 1 or 2, please refer to the section below first.

### Upgrade instructions

If you'd like to migrate to EVI 4-mini:

* Set the `evi_version` field in your Config to `"4-mini"`.
* Follow the steps in [Update an existing Config](#update-an-existing-config) to apply the change.

#### Summary

<table>
  <tbody>
    <tr>
      <th>
         Feature 
      </th>

      <th>
         EVI 3 
      </th>

      <th>
         EVI 4-mini 
      </th>
    </tr>

    <tr>
      <td>
         Languages supported 
      </td>

      <td>
         English 
      </td>

      <td>
         English, Japanese, Korean, Spanish, French, Portuguese, Italian, German, Russian, Hindi, Arabic 
      </td>
    </tr>

    <tr>
      <td>
        Quick responses
      </td>

      <td>
        Available
      </td>

      <td>
        Unavailable
      </td>
    </tr>

    <tr>
      <td>
        Supplemental LLM
      </td>

      <td>
        Optional
      </td>

      <td>
        Required
      </td>
    </tr>
  </tbody>
</table>

## Migrating to EVI 3

#### Instructions on migrating from EVI 1 or 2

This section details the changes required to migrate from EVI 1 or 2 to EVI 3, including Config updates, SDK upgrades,
and client-side message handling.

### Upgrade instructions

To upgrade to EVI 3:

* Set the `evi_version` field in your Config to `"3"`.
* Follow the steps in [Update an existing Config](#update-an-existing-config) to apply the change.

### SDK compatibility

The following are the minimum SDK versions compatible with EVI 3. If you’re using an older version, update it using
the commands below.

> **Tip**
>
> The versions below are minimums. For the newest EVI 3 features, performance improvements, and security fixes,
> upgrade to the latest SDK releases. If you run into issues, update to the latest version before troubleshooting.

[React SDK](https://www.npmjs.com/package/@humeai/voice-react) (`v0.2.1`)

#### npm

```sh
npm i @humeai/voice-react@0.2.1
```

#### pnpm

```sh
pnpm i @humeai/voice-react@0.2.1
```

#### yarn

```sh
yarn add @humeai/voice-react@0.2.1
```

#### bun

```sh
bun add @humeai/voice-react@0.2.1
```

[TypeScript SDK](https://www.npmjs.com/package/hume) (`v0.12.1`)

#### npm

```sh
npm install hume@0.12.1
```

#### pnpm

```sh
pnpm install hume@0.12.1
```

#### yarn

```sh
yarn add hume@0.12.1
```

#### bun

```sh
bun add hume@0.12.1
```

[Python SDK](https://pypi.org/project/hume/) (`v0.10.1`)

#### uv

```sh
uv add hume==0.10.1
```

#### pip

```sh
pip install hume==0.10.1
```

### Breaking changes

1. **EVI 3 introduces a new voice system**

   * **Impact**: Voice options from EVI 1 and 2 are not compatible with EVI 3.

   * **Reason**: EVI 3 is powered by a speech-language model that supports an expanded, high-quality set of voices.

   * **Action**: Use a voice from the [Voice Library](https://app.hume.ai/voices) or your [Custom voices](https://app.hume.ai/voices?category=my-voices).

2. **Voice selection is now required**

   * **Impact**: Configs that do not specify a voice must now include one.

   * **Reason**: There is no default voice for EVI 3.

   * **Action**: If your Config does not already specify a voice, update it to include one from the supported options. Our voice library includes EVI 3 clones of the popular ITO and KORA voices from EVI 1 and 2.

   <table>
     <tbody>
       <tr>
         <th>
            Voice 
         </th>

         <th>
            ID 
         </th>
       </tr>

       <tr>
         <td>
            

           [Ito](https://app.hume.ai/voices?q=Ito)

            
         </td>

         <td>
            

           `f60ecf9e-ff1e-4bae-9206-dba7c653a69e`

            
         </td>
       </tr>

       <tr>
         <td>
            

           [Kora](https://app.hume.ai/voices?q=Kora)

            
         </td>

         <td>
            

           `59cfc7ab-e945-43de-ad1a-471daa379c67`

            
         </td>
       </tr>
     </tbody>
   </table>

3. **Assistant prosody is delivered separately**

   * **Impact**: Prosody scores are no longer included in `assistant_message` payloads.

   * **Reason**: In EVI 3, prosody scores are sent asynchronously in a separate
     [`assistant_prosody`](/reference/speech-to-speech-evi/chat#receive.AssistantProsody) message. This allows for
     lower latency during speech synthesis.

   * **Action**: Use the shared `id` field to associate each `assistant_prosody` message with its corresponding
     `assistant_message`.

   #### Assistant Message

   ```json maxLines=0 highlight={3}
   {
     "type": "assistant_message",
     "id": "c90ab17c1b064aec99c753bc172e7a3c",
     "message": {
         "role": "assistant",
         "content": "Hi! How are you today?"
     },
     "from_text": false
   }
   ```

   #### Assistant Prosody Message

   ```json maxLines=0 highlight={3}
   {
     "type": "assistant_prosody",
     "id": "c90ab17c1b064aec99c753bc172e7a3c",
     "models": {
       "prosody": {
         "scores": {
           "Admiration": 0.10722749680280685,
           "Adoration": 0.06395940482616425,
           // ...etc.
         }
       }
     }
   }
   ```

#### Summary

<table>
  <tbody>
    <tr>
      <th>
         Feature 
      </th>

      <th>
         EVI 1 & 2 
      </th>

      <th>
         EVI 3 
      </th>
    </tr>

    <tr>
      <td>
         Voice options 
      </td>

      <td>
         Legacy voices 
      </td>

      <td>
         Voice Library or Custom voices 
      </td>
    </tr>

    <tr>
      <td>
         Voice selection 
      </td>

      <td>
         Optional 
      </td>

      <td>
         Required 
      </td>
    </tr>

    <tr>
      <td>
         Assistant prosody 
      </td>

      <td>
         Delivered in 

        `assistant_message`

         
      </td>

      <td>
         Delivered in 

        `assistant_prosody`

         
      </td>
    </tr>
  </tbody>
</table>

---