declare namespace NodeJS {
  export interface ProcessEnv {
    // Required. Do not share your OpenAI API key with anyone! It should remain a secret.
    OPENAI_API_KEY: string;
    // Optional. OpenAI API endpoint. Defaults to https://api.openai.com.
    OPENAI_API_ENDPOINT: string;
    // Optional. Database connection string to store the usage data.
    USAGE_DATABASE_URL: string;
    // Optional. API key to protect the backend API endpoint.
    // This needs to be exposed to the frontend and must be prefixed with NEXT_PUBLIC_.
    NEXT_PUBLIC_API_KEY: string;
  }
}