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# Assembly AI Transcriber Improvements, chat cost tracking, and API tool enhancements

1. **Chat Cost Tracking**: You can now access detailed cost information per [Chat](https://api.vapi.ai/api#:~:text=FunctionCall-,Chat,-CreateChatDTO) and [Call](https://api.vapi.ai/api#:~:text=SchedulePlan-,Call,-CallBatchError), including total and per-component breakdowns. Use `Call.cost` and `Chat.cost` to get the total cost, and `Call.costs` and `Chat.costs` to get the breakdown.\`

**`Chat Schema (excerpt)`**

```json title="Chat Schema (excerpt)"
{
  "cost": 0.12,
  "costs": [
    { "type": "model", "cost": 0.22 },
    { "type": "chat", "cost": 0.10 },
  ]
}
```

2. **Enhanced AssemblyAI Transcriber Configuration**: You can now fine-tune the AssemblyAI transcriber with:

* `maxTurnSilence`: The maximum amount of silence in milliseconds before a turn is considered complete.
* `endOfTurnConfidenceThreshold`: The confidence threshold for determining the end of a turn.
* `minEndOfTurnSilenceWhenConfident`: The minimum amount of silence in milliseconds before a turn is considered complete when the confidence is high.
* `wordFinalizationMaxWaitTime`: The maximum amount of time in milliseconds to wait for word finalization.

3. **New Cartesia Transcriber Option**: You can now use the [Cartesia "Ink Whisper" transcriber](https://api.vapi.ai/api#:~:text=CartesiaTranscriber) for your for assistants and workflow nodes using `Assistant.transcriber` and `ConversationNode.transcriber`. Set this in your [Vapi Assistant dashboard today](https://dashboard.vapi.ai/assistants#:~:text=Transcriber).

![Cartesia Transcriber](/_fern-img/b2fc8c0a395a513da31774c3bc318c3a971e9e2733136d91a9b72db41d3ecbde.webp)

4. **API Request Tool Variable Extraction**: You can now use [`assistant.model.tools[type=apiRequest].variableExtractionPlan`](https://api.vapi.ai/api#:~:text=VariableExtractionPlan) to extract and validate variables from API responses by defining a variable schema.