You can pass customer info to Vapi by including it in the server URL response that your Vapi app fetches when a call starts. Your server should return a JSON object with a customer field — for example: { "customer": { "name": "John Doe", "email": "john@example.com" } } Then, in your System Prompt, you can reference those values using {{customer.name}} and {{customer.email}}. Here’s the doc on it: 👉 https://docs.vapi.ai/docs/server-url