How to Host SolidJS Applications on Square Cloud

Hosting SolidJS on Square Cloud is simple and extremely efficient. Depending on your project's architecture, you will either follow the path of a static deployment (Solid + Vite) or run a SolidStart server.

1. Solid + Vite (Static)

With Solid + Vite, the build generates static files in dist/. In your local terminal, run:

npm run build

Publish the contents of dist/ on the static runtime (MAIN=index.html, or vite.html for SPA routes, with SUBDOMAIN and MEMORY=512). No Node.js process is needed. See Deploying a static site (HTML, React, Vite).

2. SolidStart (SSR)

SolidStart runs a real server that enables server-side rendering (SSR). Run npm run build: it generates .output/server/index.mjs, which reads the PORT and HOST that Square Cloud sets (80 and 0.0.0.0). Create a squarecloud⁠.app file:

MAIN=.output/server/index.mjs
MEMORY=1024
VERSION=recommended
DISPLAY_NAME=My SolidStart App
SUBDOMAIN=my-solidstart-app

3. Preparing the Deployment (.zip)

To ensure that the deployment is fast and error-free, your .zip file should contain only the essentials:

• For Vite: the contents of dist/ (see here).
• For SolidStart: the .output/ folder, package.json, and squarecloud⁠.app.

Tip: Never upload the node_modules folder. Square Cloud will perform a clean installation of dependencies on the server.

4. Environment Variables (ENV)

• VITE_ variables are read at build time and are visible to any visitor: set them in .env before running npm run build, and never put secrets in them.
• Dashboard variables (your application's Environment Variables tab) only reach server code (SolidStart) and are read when the application starts. Configure keys like API_URL or DB_AUTH there.

5. Performance Tips

• Hydration: If you are using SSR with SolidStart, monitor memory usage. SolidJS is highly efficient, but the server hydration process consumes resources during traffic spikes.
• Cache: Use Square Cloud's caching for static assets (images, CSS) to decrease the initial loading time (LCP).

Updated on: 10/04/2026