The classic voice engine
The default pipeline for English. Deepgram Nova-3 transcribes, GPT-4o-mini via OpenRouter reasons, and ElevenLabs speaks: Turbo v2.5 for English, Flash v2.5 for other languages. It is the cheapest composed engine and the one to start with.
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What classic runs, and what each part costs
A composed engine is three stages, each billed in its own unit. The per-minute column is what that unit adds up to at typical speech rates. The pipeline label is Deepgram + GPT-4o-mini + ElevenLabs.
| Stage | Model | Unit price | Per minute |
|---|---|---|---|
| Speech-to-text | deepgram/nova-3 | $0.0002 per second | $0.0108 |
| Language model | openrouter/gpt-4o-mini | $0.0000 per token in | $0.0005 |
| Language model | openrouter/gpt-4o-mini | $0.0000 per token out | $0.0004 |
| Text-to-speech | elevenlabs/eleven_turbo_v2_5 | $0.0001 per character | $0.0630 |
| Text-to-speech | elevenlabs/eleven_flash_v2_5 | $0.0001 per character | $0.0630 |
| Orchestration | wixzel/orchestration | $0.0120 per minute | $0.0120 |
Rounded up, never down. Where two models are listed for one stage the engine picks by language; the engine price above assumes the dearer path. All prices on the model price list.
Frequently asked questions
- What is the classic voice engine?
- classic is a composed voice engine on Wixzel Phone. The default pipeline for English. Deepgram Nova-3 transcribes, GPT-4o-mini via OpenRouter reasons, and ElevenLabs speaks: Turbo v2.5 for English, Flash v2.5 for other languages. It is the cheapest composed engine and the one to start with.
- How much does the classic engine cost per minute?
- $0.0867 per connected minute at typical speech rates, including the flat $0.012 per minute orchestration fee. The figure is generated from the price book the meter bills against and is rounded up, never down. Telephony runs over your own SIP trunk and is not included or marked up.
- Which models does the classic engine use?
- classic runs
deepgram/nova-3,openrouter/gpt-4o-mini,elevenlabs/eleven_turbo_v2_5,elevenlabs/eleven_flash_v2_5. Each stage is billed in its own unit: seconds of speech recognised, tokens in and out of the model, and characters synthesised. - Do I need my own deepgram account to use classic?
- No. The provider accounts belong to Wixzel Phone. One
wv_live_…API key and a prepaid balance cover the classic engine and every other engine; there are no provider keys to bring. - How do I use the classic engine in a call?
- Name the three stages in the agent's voice when you create it with
POST /v1/agents, for example the stt, llm and tts refs listed above, then place a call withPOST /v1/calls.GET /v1/engineslists what is available right now; an engine whose provider is degraded disappears from that list before calls start failing. - Is the classic price per minute a flat rate?
- No. $0.0867 is what a typical minute adds up to. The meter charges per second of speech, per token and per character for the models that actually ran, plus the flat orchestration fee, and every micro-dollar is itemised in
GET /v1/usage/events. A quieter or shorter turn costs less; a long monologue costs more.
Where classic is the engine to reach for
English bookings need accurate names and dates; Nova-3 transcription with GPT-4o-mini is the cheapest reliable pairing. Switch the stt language for other languages, or the sarvam engine for Indian ones.
Short, scripted outbound calls are the cheapest workload; the classic engine keeps the per-minute cost lowest for English. Use sarvam for Indian-language lists.