No Dockerfile
The platform detects Express from package.json, picks the build and start commands, and lists the environment variables your code reads.
Express deploy guide · Agent Lab Deploy
Deploy Express
in one sentence.
Upload your Express project as it is — no Dockerfile — or tell Claude Code, Codex or Cursor "deploy this". Agent Lab builds it into a web service, gives every version a preview URL with rollback, and checks uploads for leaked keys. Apps and databases run on Google Cloud in Taiwan.
> deploy this Express app
sites_createmy-express
sites_deployExpress detected
sites_deploy_statusbuilt · secret scan passed
Live at my-express--acme.hosting.agentlab.run
Why deploy Express on Agent Lab
Express online without running a server yourself
JavaScript / TypeScript project, built from source with no Dockerfile, deployed as a web service.
Preview, go live, roll back
Every upload is a new version with its own URL. Look first, then go live; switch back to any version in one click.
Leaked keys caught
Uploads are checked for API keys and credentials before they can go live. Secrets go in the console, never in the code.
PostgreSQL in one click
Create a database and connect it; the connection is written into the app's environment and the password is never shown.
Your options
Express on Agent Lab, or on your own VPS
Scroll the table sideways.
| What you care about | Agent Lab Deploy | Your own VPS |
|---|---|---|
| Setup | Upload or say one sentence; no Dockerfile | SSH, a runtime, a process manager, a reverse proxy |
| HTTPS and domains | Automatic, custom domains on paid plans | Certbot and DNS by hand |
| Preview and rollback | Every version has its own URL; roll back in one click | Write your own scripts |
| Before going live | Uploads checked for leaked keys | Nothing unless you set it up |
| Database | PostgreSQL in one click, connection written into the app | Install and back it up yourself |
| Cost to start | Free plan: NT$0, one size-S app (sleeps when idle) | A VPS at roughly NT$200–600 a month, plus your time |
Steps
Deploy Express in four steps
Prepare
Keep package.json at the top of the project and commit the lockfile. Leave out node_modules, .git, dist and .env.
Upload or ask
Drop the folder on a project's Deploy tab, push from GitHub, or ask your AI tool through Agent Lab MCP.
Build and check
The platform builds the version and checks it for leaked keys. Enter any secrets it lists in Settings.
Preview and go live
The first version goes live once it builds. Later ones get a preview URL; go live when you're happy.
Setup
What Agent Lab runs for Express
package.json needs a start script (such as node server.js); with TypeScript add a build script and the platform builds first. Only /tmp is writable; store uploaded files in object storage or the database.
Build and start
// 程式只要監聽 PORT / The code only has to listen on PORT
const port = Number(process.env.PORT ?? 8080);
app.listen(port);
# Agent Lab 執行 / Agent Lab runs
npm ci
npm start # package.json 的 start scriptPORTthe port the platform gives (8080 by default); the server must listen on it.DATABASE_URLwritten for you when you connect an Agent Lab PostgreSQL.SESSION_SECRETgenerate it in the console.
Or ask your AI tool
Read https://app.agentlab.cresclab.com/agent/deploy.md and deploy this Express project to Agent Lab. Show me the build plan and the environment variables it needs first, tell me where to enter any secrets, and wait for my OK before it goes live.FAQ
Deploying Express: questions
Do I need a Dockerfile to deploy Express?
No. Upload the Express project with package.json at the top and Agent Lab detects the framework, builds it and starts it. A Dockerfile at the top, if there is one, is used instead. Docs →
Does Express have to listen on PORT?
Yes. The platform puts the port in the PORT environment variable (8080 by default); the server must listen on it, on all interfaces (0.0.0.0), not only localhost. A version that never becomes ready is almost always listening on the wrong port.
Where do API keys and other secrets go?
In the project's Settings, under Secrets; the code reads them as environment variables. Random values such as session secrets can be generated in the console without anybody seeing them. A key found in an upload stops it before it goes live.
Can I deploy Express from Claude Code or Codex?
Yes. Connect Agent Lab MCP once (one command, sign in in the browser, no API key), then say "deploy this Express app". The tool creates the project, uploads, waits for the build and asks before going live. Connect MCP →
Is there a free way to host Express?
The Free plan is NT$0: one size-S app that sleeps after 15 idle minutes, one size-S database, three static web pages, 100 build minutes and 5 GB of traffic a month, pausing at the limit instead of charging. Pro (US$29 a month before tax) keeps apps running and adds custom domains. Pricing →