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What are Agents?

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

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Character Interface

The complete TypeScript interface for agents:
PropertyTypeRequiredDescription
namestring✅Agent’s display name
biostring | string[]✅Background/personality description
adjectivesstring[]❌Character traits (e.g., “helpful”, “creative”)
topicsstring[]❌Conversation topics the agent knows
knowledgearray❌Facts, files, or directories of knowledge
messageExamplesarray[][]❌Example conversations (2D array)
postExamplesstring[]❌Example social media posts
styleobject❌Writing style for different contexts
pluginsstring[]❌Enabled plugin packages
settingsobject❌Configuration values
secretsobject❌Sensitive configuration
idUUID❌Unique identifier
usernamestring❌Social media username
systemstring❌System prompt override
templatesobject❌Custom prompt templates

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Style Object Structure

style: {
  all?: string[];        // General style rules
  chat?: string[];       // Chat-specific style
  post?: string[];       // Post-specific style
}

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Templates Object Structure

templates?: Templates;     // Custom prompt templates

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Working Example

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"] : [])
  ]
};

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Knowledge Configuration

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

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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;
}

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Character Definition

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

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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

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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

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Next Steps

Add Plugins

Extend your agent’s capabilities

Build Projects

Create multi-agent systems