client.js

let Liftoff = require("liftoff");
let { jsVariants } = require("interpret");

new Liftoff(
  {
    name: "echo",
    configName: "echo.config",
    extensions: jsVariants
  }
).launch({}, (env) => {
  // echo.config.js or echo.config.babel.js
  let configPath = env.configPath;
  console.log(`loading ${configPath}`);
  require(configPath);
});