Deploy Next.js app to Netlify via API

index.ts

import { NetlifyAPI } from "netlify";

// https://app.netlify.com/user/applications#personal-access-tokens
const client = new NetlifyAPI("nfp_YGNVq");

async function main() {
  // create empty site
  const site = await client.createSite().catch((err) => console.log(err));

  if (!site) return;
  console.log(site);

  // https://open-api.netlify.com/#tag/environmentVariables/operation/createEnvVars
  await client
    .createEnvVars({
      account_id: site.account_id as string,
      site_id: site.id,
      body: [
        {
          key: "NEXT_PUBLIC_VAR",
          values: [{ value: "NEXT_PUBLIC_VALUE" }],
        },
      ],
    })
    .catch((err) => console.log(err));

  // https://open-api.netlify.com/#/default/createSite
  await client
    .updateSite({
      site_id: site.id as string,
      body: {
        name: `my-awesome-site-abcdef`,
        repo: {
          provider: "gitlab",
          repo_path: "leon-do/next-env-lab",
          repo_branch: "main",
          dir: ".next",
          cmd: "npm run build",
        },
      },
    })
    .catch((err) => console.log(err));
}
main();