# .env.local
OPENAI_API_KEY=sk-...

<YourGPTProvider
  runtimeUrl="/api/chat"
  llm={{
    provider: 'openai',
    model: 'gpt-4o',
  }}
>
  <CopilotChat />
</YourGPTProvider>

llm={{
  provider: 'openai',
  model: 'gpt-4o',
  temperature: 0.7,        // 0-2, default 1
  maxTokens: 4096,         // Max response length
  topP: 1,                 // Nucleus sampling
  frequencyPenalty: 0,     // -2 to 2
  presencePenalty: 0,      // -2 to 2
}}

const { sendMessage } = useYourGPT();

// Send message with image
sendMessage("What's in this image?", [
  {
    type: 'image',
    data: base64ImageData,
    mimeType: 'image/png',
  }
]);

useToolWithSchema({
  name: 'search_products',
  description: 'Search for products',
  schema: z.object({
    query: z.string(),
    category: z.string().optional(),
  }),
  handler: async ({ query, category }) => {
    // OpenAI reliably extracts structured parameters
    const results = await searchProducts(query, category);
    return { success: true, data: results };
  },
});