OpenAI

OpenAI's GPT series models are the industry benchmark for conversational AI, known for strong reasoning, instruction-following, and natural dialogue quality. With GPT-5.5 offering multimodal capabilities and low latency, it's the default choice for most voice AI applications that demand top-tier language understanding.
Usage
To use OpenAI as the LLM engine, pass the following JSON in the LLMConfig field of the StartAIConversation API:
// json — LLMConfig
{
  "LLMType": "openai",
  "Model": "gpt-5.5",
  "APIKey": "<your_openai_api_key>",
  "APIUrl": "https://api.openai.com/v1/chat/completions",
  "Streaming": true,
  "SystemPrompt": "You are a helpful voice assistant.",
  "Timeout": 3.0,
  "History": 5,
  "MetaInfo": {}
}
For full Conversational AI configuration (STT, TTS, interruption handling, VAD, etc.), see the TRTC Conversational AI API Reference.
Parameter reference
Field
Type
Required
Description
LLMType
String
Yes
Fixed value: "openai".
Model
String
Yes
Model name: gpt-5.5, gpt-5.4, gpt-4o-minietc. See OpenAI Models.
APIKey
String
Yes
Your OpenAI API key. Obtain from OpenAI Platform.
APIUrl
String
Yes
OpenAI chat completions endpoint.
Streaming
Boolean
No
Enable streaming responses. Default: true.
SystemPrompt
String
No
System instruction to guide model behavior.
Timeout
Float
No
Timeout in seconds. Default: 3.
History
Integer
No
Conversation turns for context. Default: 0. Max: 50.
MetaInfo
Object
No
Custom parameters passed in the request body.
For more details on OpenAI models and API, see the OpenAI documentation.
Next step: Configure your TTS provider﻿
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Field	Type	Required	Description
`LLMType`	String	Yes	Fixed value: `"openai"`.
`Model`	String	Yes	Model name: `gpt-5.5`, `gpt-5.4`, `gpt-4o-mini`etc. See OpenAI Models.
`APIKey`	String	Yes	Your OpenAI API key. Obtain from OpenAI Platform.
`APIUrl`	String	Yes	OpenAI chat completions endpoint.
`Streaming`	Boolean	No	Enable streaming responses. Default: `true`.
`SystemPrompt`	String	No	System instruction to guide model behavior.
`Timeout`	Float	No	Timeout in seconds. Default: 3.
`History`	Integer	No	Conversation turns for context. Default: 0. Max: 50.
`MetaInfo`	Object	No	Custom parameters passed in the request body.