/setup-portless

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.

<objective> 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. </objective>

<quick_start> Run these commands to get started:

# Install globally
npm install -g portless

# Start the proxy daemon
portless proxy start

# Run your app with a named route
portless myapp next dev
# => http://myapp.localhost:1355

</quick_start>

<process>

**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

</process>

<common_patterns>

<pattern name="single-app"> **Single application:**

{
  "scripts": {
    "dev": "portless myapp next dev"
  }
}

Access at: `http://myapp.localhost:1355` </pattern>

<pattern name="monorepo"> **Monorepo with multiple services:**

# In packages/web/package.json
"dev": "portless web.myapp next dev"

# In packages/api/package.json
"dev": "portless api.myapp node server.js"

# In packages/docs/package.json
"dev": "portless docs.myapp next dev"

Access at:

• `http://web.myapp.localhost:1355`
• `http://api.myapp.localhost:1355`
• `http://docs.myapp.localhost:1355`

</pattern>

<pattern name="custom-proxy-port"> **Custom proxy port (e.g., port 80 for clean URLs):**

sudo portless proxy start -p 80
# Then: http://myapp.localhost (no port needed)

</pattern>

</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>

<pitfall name="forgetting-proxy"> The proxy auto-starts when you run `portless <name> <cmd>`, so there is no need to manually start it. Only use `portless proxy start` for custom port configuration. </pitfall>

<pitfall name="windows"> Portless does not support Windows. Only set up on macOS or Linux. </pitfall>

<pitfall name="old-node"> Portless requires Node.js 20+. Do not attempt installation on older versions. </pitfall>

</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>