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Overview

By default, every Lua agent uses Google Gemini 2.5 Flash. The model property on LuaAgent lets you choose a different model or select one dynamically based on the request context. 
export const agent = new LuaAgent({
  name: 'my-agent',
  persona: '...',
  model: 'openai/gpt-4o',  // ← add this
  skills: [mySkill]
});
Lua manages the API credentials. You don’t need to configure any API keys or provider accounts — Lua handles all LLM infrastructure on your behalf.Support for user-provided API keys (Bring Your Own Key) is coming in a future release.

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Available Models

Model stringProviderContext window
google/gemini-2.5-flashGoogle (Vertex AI)1M tokens (default)
google/gemini-2.5-proGoogle (Vertex AI)1M tokens
google/gemini-2.0-flashGoogle (Vertex AI)1M tokens
openai/gpt-4oOpenAI128K tokens
openai/gpt-4o-miniOpenAI128K tokens
openai/gpt-4.1OpenAI1M tokens
openai/gpt-4.1-miniOpenAI1M tokens
anthropic/claude-3.5-sonnetAnthropic200K tokens
anthropic/claude-3.7-sonnetAnthropic200K tokens

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Static Model

The simplest form — one model for all requests: 
export const agent = new LuaAgent({
  name: 'support-agent',
  persona: '...',
  model: 'openai/gpt-4o',
  skills: [supportSkill]
});
When to use: When you want a specific model across all users and channels.

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Dynamic Model Resolver

Use a function to select the model per request. The resolver receives the full request with access to all platform APIs — User, Baskets, Products, Data, and more. 
export const agent = new LuaAgent({
  name: 'smart-agent',
  persona: '...',
  model: async (request) => {
    const user = await User.get();
    return user.data?.isPremium ? 'openai/gpt-4o' : 'google/gemini-2.5-flash';
  },
  skills: [mySkill]
});
The resolver must return a 'provider/model' string synchronously or asynchronously.

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Common Patterns

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Premium vs free users

model: async (request) => {
  const user = await User.get();
  const tier = user.data?.subscriptionTier;

  if (tier === 'pro') return 'openai/gpt-4.1';        // large context
  if (tier === 'standard') return 'openai/gpt-4o';     // balanced
  return 'google/gemini-2.5-flash';                    // default
}

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Channel-based selection

model: (request) => {
  // Use a faster/cheaper model for voice channels
  if (request.channel === 'voice') return 'google/gemini-2.0-flash';
  // Use a more capable model for complex web requests
  return 'openai/gpt-4o';
}

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Content-based routing

model: async (request) => {
  // Use a model with large context for document-heavy workflows
  const basketCount = await Baskets.getCount();
  if (basketCount > 50) return 'openai/gpt-4.1';  // 1M context
  return 'openai/gpt-4o';
}

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Environment-based

import { env } from 'lua-cli';

model: env('PREFERRED_MODEL') || 'google/gemini-2.5-flash'

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Default Model

If you don’t set model, your agent uses google/gemini-2.5-flash. This is a fast, capable model with a 1M token context window — suitable for most use cases.

LuaAgent API

Full constructor reference including the model param

Platform APIs

APIs available inside a model resolver function