ResourcesIntegrationsLarge language models

OpenAI

Use OpenAI GPT models with your Vapi voice agent.

OpenAI provides language models for Vapi voice agents.

You can use OpenAI through Vapi’s default integration, or connect your own account in Integrations.

Supported capability

CapabilityProvider value
Language modelopenai

Language model

Set model.provider to openai and model.model to a GPT model.

$curl -X PATCH "https://api.vapi.ai/assistant/ASSISTANT_ID" \
>  -H "Authorization: Bearer $VAPI_API_KEY" \
>  -H "Content-Type: application/json" \
>  -d '{
>    "model": { "provider": "openai", "model": "gpt-4.1" }
>  }'

For additional API configuration options, review the OpenAIModel fields in the Create Assistant API reference.

ModelModel ID
GPT 5.6 Solgpt-5.6-sol
GPT 5.6 Terragpt-5.6-terra
GPT 5.6 Lunagpt-5.6-luna
GPT 5.5gpt-5.5
GPT Instant (latest)chat-latest
GPT 5.4gpt-5.4
GPT 5.4 Minigpt-5.4-mini
GPT 5.4 Nanogpt-5.4-nano
GPT 5.2gpt-5.2
GPT 5.1gpt-5.1
GPT 5gpt-5
GPT 5 Minigpt-5-mini
GPT 5 Nanogpt-5-nano
GPT 4.1gpt-4.1
GPT 4.1 Minigpt-4.1-mini
GPT 4o Minigpt-4o-mini
GPT Realtime 2gpt-realtime-2
o3o3
OpenAI text-to-speech

Configure OpenAI for text-to-speech.

OpenAI speech-to-text

Configure OpenAI for speech-to-text.

Model providers

Compare every language model provider Vapi supports.