Agents

AI personalities in elizaOS

What are Agents?

Agents = AI personalities with memory, actions, and unique behaviors.

Character Interface

The complete TypeScript interface for agents:

Property	Type	Required	Description
name	string	✅	Agent’s display name
bio	string | string[]	✅	Background/personality description
adjectives	string[]	❌	Character traits (e.g., “helpful”, “creative”)
topics	string[]	❌	Conversation topics the agent knows
knowledge	array	❌	Facts, files, or directories of knowledge
messageExamples	array[][]	❌	Example conversations (2D array)
postExamples	string[]	❌	Example social media posts
style	object	❌	Writing style for different contexts
plugins	string[]	❌	Enabled plugin packages
settings	object	❌	Configuration values
secrets	object	❌	Sensitive configuration
id	UUID	❌	Unique identifier
username	string	❌	Social media username
system	string	❌	System prompt override
templates	object	❌	Custom prompt templates
all?: string[]; // General style rules
chat?: string[]; // Chat-specific style
post?: string[]; // Post-specific style
};

// Advanced templates?: Templates; // Custom prompt templates }

## Working Example

```typescript
export const character: Character = {
  name: "Eliza",
  bio: [
    "Helpful AI assistant",
    "Expert in technical topics",
    "Friendly conversationalist"
  ],
  adjectives: ["helpful", "knowledgeable", "friendly"],
  topics: ["technology", "programming", "general knowledge"],
  
  // 2D array: each sub-array is a conversation
  messageExamples: [[
    {
      name: "{{user}}",
      content: { text: "Can you help me debug this?" }
    },
    {
      name: "Eliza",
      content: { text: "I'd be happy to help! Can you share the error message?" }
    }
  ]],
  
  style: {
    all: ["be concise", "use examples"],
    chat: ["be conversational"],
    post: ["use emojis sparingly"]
  },
  
  // Plugins loaded based on environment
  plugins: [
    "@elizaos/plugin-bootstrap", // Core functionality
    ...(process.env.DISCORD_API_TOKEN ? ["@elizaos/plugin-discord"] : []),
    ...(process.env.OPENAI_API_KEY ? ["@elizaos/plugin-openai"] : [])
  ]
};

Knowledge Configuration

// String facts
knowledge: ["I am an AI assistant", "I help with coding"]

Memory & Runtime

Agents remember:

• Recent conversations
• Important facts about users
• Context from previous interactions

At runtime, characters become Agent instances with status tracking:

interface Agent extends Character {
  enabled?: boolean;
  status?: 'active' | 'inactive';
  createdAt: number;
  updatedAt: number;
}

Character Definition

Characters can be defined in TypeScript (recommended) or JSON:

TypeScript (Recommended)

import { Character } from '@elizaos/core';

export const character: Character = {
  name: "TechHelper",
  bio: [
    "AI assistant specialized in technology",
    "Expert in web development"
  ],
  // ... rest of configuration
};

JSON

{
"name": "TechHelper",
"bio": [
"An AI assistant specialized in technology and programming",
"Loves helping developers solve problems",
"Expert in web development and open source"
],
"adjectives": [
"helpful",
"technical", 
"precise",
"friendly"
],
"topics": [
"programming",
"web development",
"open source",
"debugging"
],
"messageExamples": [
[
  {
    "name": "User",
    "content": {"text": "I'm having trouble with my React app"}
  },
  {
    "name": "TechHelper", 
    "content": {"text": "I'd be happy to help debug your React app! Can you describe what specific issue you're encountering?"}
  }
]
],
"postExamples": [
"Just discovered an awesome new debugging technique for React apps! Thread below 🧵",
"Open source tip: Always read the contributing guidelines before submitting a PR 📖"
],
"style": {
"all": [
  "use technical terms accurately",
  "provide code examples when relevant",
  "be encouraging and supportive"
],
"chat": [
  "ask clarifying questions",
  "break down complex topics",
  "offer step-by-step guidance"
],
"post": [
  "share useful tips and tricks",
  "use relevant emojis sparingly",
  "create engaging technical content"
]
},
"knowledge": [
"I specialize in modern web development frameworks",
{"path": "./knowledge/react-guide.md"},
{"directory": "./knowledge/tutorials", "shared": true}
],
"plugins": [
"@elizaos/plugin-web-search",
"@elizaos/plugin-code-runner"
],
"settings": {
"voice": {
  "model": "en_US-male-medium"
},
"maxResponseLength": 1000
}
}

Creating an Agent

1. Define your character

   Create character.ts or character.json

2. Add plugins

   plugins: [
     "@elizaos/plugin-bootstrap",
     "@elizaos/plugin-discord" 
   ]
   
3. Start the agent

   elizaos start
   

Best Practices

• Keep personality traits consistent
• Provide diverse message examples
• Focus knowledge on the agent’s purpose
• Test conversations before deploying
• Use TypeScript for better type safety
• Load plugins conditionally based on environment

Next Steps

Add Plugins

Extend your agent’s capabilities

Build Projects

Create multi-agent systems