Updates the description of a **Config**.

For more details on configuration options and how to configure EVI, see our [configuration guide](https://dev.hume.ai/docs/speech-to-speech-evi/configuration).

### Authentication

**X-Hume-Api-Key**  
API Key authentication via header

### Path parameters

- **id**: string Required  
  Identifier for a Config. Formatted as a UUID.
- **version**: integer Required  
  Version number for a Config.

Configs, Prompts, Custom Voices, and Tools are versioned. This versioning system supports iterative development, allowing you to progressively refine configurations and revert to previous versions if needed.

Version numbers are integer values representing different iterations of the Config. Each update to the Config increments its version number.

### Request

This endpoint expects an object.

- **version_description**: string or null Optional  
  An optional description of the Config version.

### Response

**Success**

- **builtin_tools**: list of objects or null  
  List of built-in tools associated with this Config.  
  Show 3 properties
- **created_on**: long  
  Time at which the Config was created. Measured in seconds since the Unix epoch.
- **ellm_model**: object  
  A specific eLLM Model configuration  
  Show 1 property
- **event_messages**: object  
  Collection of event messages returned by the server.  
  Event messages are sent by the server when specific events occur during a chat session. These messages are used to configure behaviors for EVI, such as controlling how EVI starts a new conversation.  
  Show 3 properties
- **evi_version**: string  
  Specifies the EVI version to use. See our [EVI Version Guide](https://dev.hume.ai/docs/speech-to-speech-evi/configuration/evi-version) for differences between versions.

**We’re officially sunsetting EVI versions 1 and 2 on August 30, 2025**. To keep things running smoothly, be sure to [migrate to EVI 3](https://dev.hume.ai/docs/speech-to-speech-evi/configuration/evi-version#migrating-to-evi-3) before then.

- **id**: string  
  Identifier for a Config. Formatted as a UUID.
- **interruption**: object  
  An interruption configuration returned from the server  
  Show 1 property
- **language_model**: object  
  A specific LanguageModel  
  Show 3 properties
- **modified_on**: long  
  Time at which the Config was last modified. Measured in seconds since the Unix epoch.
- **name**: string  
  Name applied to all versions of a particular Config.
- **nudges**: object  
  A specific nudge configuration returned from the server  
  Show 2 properties
- **prompt**: object  
  A specific prompt version returned from the server  
  Show 9 properties
- **timeouts**: object  
  Collection of timeout specifications returned by the server.
  Timeouts are sent by the server when specific time-based events occur during a chat session. These specifications set the inactivity timeout and the maximum duration an EVI WebSocket connection can stay open before it is automatically disconnected.
  Show 2 properties
- **tools**: list of objects or null  
  List of user-defined tools associated with this Config.  
  Show 11 properties
- **turn_detection**: object  
  A turn detection configuration returned from the server  
  Show 3 properties
- **version**: integer  
  Version number for a Config.

Version numbers are integer values representing different iterations of the Config. Each update to the Config increments its version number.

- **version_description**: string or null  
  An optional description of the Config version.
- **voice**: object  
  An Octave voice available for text-to-speech  
  Show 4 properties
- **webhooks**: list of objects or null  
  Map of webhooks associated with this config.  
  Show 2 properties