rasengan/lib/esm/server/runtime/detect-runtime.js

The modern React Framework

export function detectRuntime() {
    if (process.env.VERCEL === '1') {
        return 'vercel';
    }
    if (process.env.NETLIFY === 'true') {
        return 'netlify';
    }
    if (process.env.NODE_ENV === 'development' ||
        process.env.NODE_ENV === 'test') {
        return 'local';
    }
    return 'unknown';
}