| name | setup-portless |
| description | Sets up Portless for a project to replace port numbers with stable named .localhost URLs. Use when configuring local development routing, fixing port conflicts, or setting up monorepo dev environments. |
Set up [Portless](https://github.com/vercel-labs/portless) for the current project. Portless replaces `localhost:PORT` with stable named URLs like `myapp.localhost:1355`, eliminating port conflicts, cookie collisions, and port-guessing issues for both developers and AI agents.
Requirements: Node.js 20+, macOS or Linux.
<quick_start>
Run these commands to get started:
npm install -g portless
portless proxy start
portless myapp next dev
</quick_start>
Step 1: Verify prerequisites
Check Node.js version is 20+ and platform is macOS or Linux:
node --version
uname -s
If Node.js < 20, inform the user they need to upgrade before proceeding.
Step 2: Detect project context
Read package.json to understand:
- Project name (use as default app name)
- Existing dev scripts (to know what command to wrap)
- Whether this is a monorepo (look for
workspaces field, or pnpm-workspace.yaml, turbo.json, lerna.json)
- Framework in use (Next.js, Vite, Express, etc.) from dependencies
Step 3: Install Portless
npm install -g portless
Step 4: Choose app name(s)
Ask the user what name they want for their app URL. Suggest based on project name.
For monorepos, suggest subdomain naming:
api.projectname for backend
web.projectname or projectname for frontend
docs.projectname for documentation
Step 5: Update package.json scripts
Wrap the existing dev script with portless. For example, if the current script is:
{ "dev": "next dev" }
Update to:
{ "dev": "portless myapp next dev" }
For monorepos, update each workspace's package.json similarly.
Step 6: Verify setup
Run the dev script and confirm the app is accessible at the named URL:
npm run dev
The proxy auto-starts if not already running. Confirm output shows the .localhost:1355 URL.
Verify routes are registered:
portless list
<common_patterns>
**Single application:**
{
"scripts": {
"dev": "portless myapp next dev"
}
}
Access at: http://myapp.localhost:1355
**Monorepo with multiple services:**
"dev": "portless web.myapp next dev"
"dev": "portless api.myapp node server.js"
"dev": "portless docs.myapp next dev"
Access at:
http://web.myapp.localhost:1355
http://api.myapp.localhost:1355
http://docs.myapp.localhost:1355
**Custom proxy port (e.g., port 80 for clean URLs):**
sudo portless proxy start -p 80
</common_patterns>
<environment_variables>
| Variable | Purpose | Default |
|---|
PORTLESS=0 or PORTLESS=skip | Bypass portless, use default port | (not set) |
PORTLESS_PORT | Override proxy port | 1355 |
PORTLESS_STATE_DIR | Custom state directory | ~/.portless or /tmp/portless |
</environment_variables>
<cli_reference>
| Command | Purpose |
|---|
portless <name> <cmd> [args...] | Run app with named route |
portless list | Show active routes |
portless proxy start | Start daemon proxy on port 1355 |
portless proxy start -p <port> | Start on custom port |
portless proxy start --foreground | Run in foreground (debugging) |
portless proxy stop | Stop the proxy daemon |
</cli_reference>
<anti_patterns>
The proxy auto-starts when you run `portless `, so there is no need to manually start it. Only use `portless proxy start` for custom port configuration.
Portless does not support Windows. Only set up on macOS or Linux.
Portless requires Node.js 20+. Do not attempt installation on older versions.
</anti_patterns>
<success_criteria>
Setup is complete when:
- Portless is installed globally (
portless --version succeeds)
- Project
package.json dev script(s) are wrapped with portless <name>
- Running
npm run dev (or equivalent) shows the app accessible at <name>.localhost:1355
- For monorepos, each workspace has its own named route
</success_criteria>