Character Definition

NavTalk supports the customization of digital personas' personalities, language styles, welcome messages, automatic response rules, and contextual memory capabilities through the instructions field in the session.update request, enabling highly tailored behaviors of digital entities.

By configuring the instructions, you can set the following:

The behavioral style and professional background of the digital persona
The response language (Chinese, English, Japanese, etc.)
The initial welcome message
The function call trigger rules
Contextual memory and personalized preferences
Voice emotional characteristics

Configuration Entry: `session.update` Request Body

When establishing a connection with the OpenAI Realtime API, send the session with configured instructions:

const instructions = `
  ${activeCharacter.characterDefinition}.
  Please respond in ${userLanguage}.
  Please greet the user with: "${activeCharacter.greeting}".
  When encountering requests beyond conversational capabilities, 
  automatically trigger function calls for:
  - Multimedia content generation (images/audio/video)
  - Real-time data queries (weather/stocks, etc.)
  - Business system interactions (CRM/ERP, etc.)

  Current context: ${messageConfig}
`;

const sessionConfig = {
  type: "session.update",
  session: {
    instructions,
    voice: "nova", // Optional voice type (see the voice list below)
    temperature: 1,
    modalities: ["text", "audio"],
    input_audio_format: "pcm16",
    output_audio_format: "pcm16",
    input_audio_transcription: {
      model: "whisper-1"
    }
  }
};

socket.send(JSON.stringify(sessionConfig));

Parameter Descriptions:

parameter name

type

example

explanation

characterDefinition

string

You are a gentle and rational psychologist

This is my input: Used to set personality, tone, professional background, etc

userLanguage

string

zh-CN / en-US / ja-JP

Control the output language

greeting

string

"Hello, I am your intelligent assistant."

An optional welcome message that supports variables

function call rules

string

The natural language description of the timing for invocation.

Describe the scenarios in which functions are called automatically

messageConfig

object

Contains a JSON object with a summary of historical dialogues, user preferences, etc

Used to inject the current contextual information (supporting AI + user content)

voice

string

"nova"

Specify the desired voice style (see below)

Behavioral Style and Professional Background of the Digital Persona

By configuring characterDefinition, you can define the digital persona's personality traits, tone style, knowledge background, and communication habits.

Example setting

Description

You are a gentle and rational counselor, skilled in listening and empathy.

This is my input: For mental health applications

You are a witty and humorous virtual host, skilled at creating a lively atmosphere.

This is suitable for live interaction and entertainment content.

You are a business consultant with 20 years of experience, known for your clear, concise, and professional communication.

The improved English version is: "For enterprise customer service and knowledge inquiries."

Response Language Setting(`userLanguage` )

You can specify the dialogue language for the digital persona using the userLanguage parameter, which supports various languages such as Chinese, English, Japanese, etc.

language

parameter value

Chinese

zh-CN

English

en-US

Japanese

ja-JP

Note:

After setting, all response content will be generated in that language.
If this setting is absent in the instructions, the system will default to automatically recognizing the user's input language.

Initial Welcome Message (`greeting`)

The digital persona can initiate the first conversation proactively by setting a welcome message after establishing a connection.

parameter name

type

example

greeting

string

"Hello, I am your intelligent assistant. How can I assist you?"

Function Call Trigger Rules

NavTalk supports seamless integration between the digital persona and external systems using OpenAI Function Calling technology (e.g., databases, weather APIs, order inquiries).