Deploy a Fastify app that uses npm

Q: How do I change the npm install command?

Run ezhst build set --install " ", then ezhst redeploy. Pass an empty string to return to auto-detection.

EasyHost picks npm when it finds package-lock.json. There is nothing to configure, and these are the exact commands it runs for Fastify.

Last updated November 9, 2026

What EasyHost runs

Step	Command
Lockfile	`package-lock.json`
Install	`npm ci`
Build	your package build script if you have one; skipped otherwise
Start	`scripts.start`, then `main`, `index.js` or `server.js`

Scripts run with npm run <script>. Dev dependencies are available during the build, and the app runs with NODE_ENV=production.

Deploy

Fastify binds to localhost by default, so you must pass host: "0.0.0.0".

npx ezhst projects create my-project --link
npx ezhst apps create my-app
npx ezhst link --project <project-slug> --app <app-slug>
npx ezhst env import .env
npx ezhst deploy

Things to watch with npm

npm ci fails if the lockfile and package.json disagree. Run npm install locally and deploy again. npm 11 lockfiles need Node 24.

Commit package-lock.json. Without any lockfile, EasyHost falls back to npm install. To replace the install step, run ezhst build set --install "<command>".

Next steps

See the Fastify hub for every Fastify guide, or free Fastify hosting for what is included.

Frequently asked questions

How do I change the npm install command?

Run ezhst build set --install "<command>", then ezhst redeploy. Pass an empty string to return to auto-detection.

Start for free

Install the skill, choose Global or Local, then tell your agent to deploy. No credit card, no config files.

npx ezhst skill install