portless

Replace port numbers with stable, named .localhost URLs for local development. For humans and agents.

- "dev": "next dev"                  # http://localhost:3000
+ "dev": "portless run next dev"     # https://myapp.localhost

Install

npm install -g portless

Install globally. Do not add as a project dependency or run via npx.

Run your app

# Enable HTTPS (one-time setup, auto-generates certs)
portless proxy start --https

portless myapp next dev
# -> https://myapp.localhost

# Without --https, runs on port 1355
portless myapp next dev
# -> http://myapp.localhost:1355

The proxy auto-starts when you run an app. A random port (4000--4999) is assigned via the PORT environment variable. Most frameworks (Next.js, Express, Nuxt, etc.) respect this automatically. For frameworks that ignore PORT (Vite, Astro, React Router, Angular, Expo, React Native), portless auto-injects --port and --host flags.

Use in package.json

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

Subdomains

Organize services with subdomains:

portless api.myapp pnpm start
# -> http://api.myapp.localhost:1355

portless docs.myapp next dev
# -> http://docs.myapp.localhost:1355

By default, only explicitly registered subdomains are routed (strict mode). Use --wildcard when starting the proxy to allow any subdomain of a registered route to fall back to that app (e.g. tenant1.myapp.localhost:1355 routes to the myapp app without extra registration).

Git Worktrees

portless run automatically detects git worktrees. In a linked worktree, the branch name is prepended as a subdomain so each worktree gets its own URL without any config changes:

# Main worktree -- no prefix
portless run next dev   # -> http://myapp.localhost:1355

# Linked worktree on branch "fix-ui"
portless run next dev   # -> http://fix-ui.myapp.localhost:1355

Use --name to override the inferred base name while keeping the worktree prefix:

portless run --name myapp next dev   # -> http://fix-ui.myapp.localhost:1355

Put portless run in your package.json once and it works everywhere -- the main checkout uses the plain name, each worktree gets a unique subdomain. No collisions, no --force.

Custom TLD

By default, portless uses .localhost which auto-resolves to 127.0.0.1 in most browsers. If you prefer a different TLD (e.g. .test), use --tld:

sudo portless proxy start --https --tld test
portless myapp next dev
# -> https://myapp.test

The proxy auto-syncs /etc/hosts for custom TLDs when started with sudo, so .test domains resolve correctly.

Recommended: .test (IANA-reserved, no collision risk). Avoid .local (conflicts with mDNS/Bonjour) and .dev (Google-owned, forces HTTPS via HSTS).

How it works

flowchart TD
    Browser["Browser<br>myapp.localhost:1355"]
    Proxy["portless proxy<br>(port 1355)"]
    App1[":4123<br>myapp"]
    App2[":4567<br>api"]

    Browser -->|port 1355| Proxy
    Proxy --> App1
    Proxy --> App2

Start the proxy -- auto-starts when you run an app, or start explicitly with portless proxy start
Run apps -- portless <name> <command> assigns a free port and registers with the proxy
Access via URL -- http://<name>.localhost:1355 routes through the proxy to your app

HTTP/2 + HTTPS

Enable HTTP/2 for faster dev server page loads. Browsers limit HTTP/1.1 to 6 connections per host, which bottlenecks dev servers that serve many unbundled files (Vite, Nuxt, etc.). HTTP/2 multiplexes all requests over a single connection.

# Start with HTTPS/2 -- generates certs and trusts them automatically
portless proxy start --https

# First run prompts for sudo once to add the CA to your system trust store.
# After that, no prompts. No browser warnings.

# Make it permanent (add to .bashrc / .zshrc)
export PORTLESS_HTTPS=1
portless proxy start    # HTTPS by default now

# Use your own certs (e.g., from mkcert)
portless proxy start --cert ./cert.pem --key ./key.pem

# If you skipped sudo on first run, trust the CA later
sudo portless trust

On Linux, portless trust supports Debian/Ubuntu, Arch, Fedora/RHEL/CentOS, and openSUSE (via update-ca-certificates or update-ca-trust). On Windows, it uses certutil to add the CA to the system trust store.

Commands

portless run [--name <name>] <cmd> [args...]  # Infer name (or override with --name), run through proxy
portless <name> <cmd> [args...]  # Run app at http://<name>.localhost:1355
portless alias <name> <port>     # Register a static route (e.g. for Docker)
portless alias <name> <port> --force  # Overwrite an existing route
portless alias --remove <name>   # Remove a static route
portless list                    # Show active routes
portless trust                   # Add local CA to system trust store
portless hosts sync              # Add routes to /etc/hosts (fixes Safari)
portless hosts clean             # Remove portless entries from /etc/hosts

# Disable portless (run command directly)
PORTLESS=0 pnpm dev              # Bypasses proxy, uses default port

# Proxy control
portless proxy start             # Start the proxy (port 1355, daemon)
portless proxy start --https     # Start with HTTP/2 + TLS
portless proxy start -p 80       # Start on port 80 (requires sudo)
portless proxy start --foreground  # Start in foreground (for debugging)
portless proxy start --wildcard  # Allow unregistered subdomains to fall back to parent
portless proxy stop              # Stop the proxy

Options

-p, --port <number>              Port for the proxy (default: 1355)
--https                          Enable HTTP/2 + TLS with auto-generated certs
--cert <path>                    Use a custom TLS certificate (implies --https)
--key <path>                     Use a custom TLS private key (implies --https)
--no-tls                         Disable HTTPS (overrides PORTLESS_HTTPS)
--foreground                     Run proxy in foreground instead of daemon
--tld <tld>                      Use a custom TLD instead of .localhost (e.g. test)
--wildcard                       Allow unregistered subdomains to fall back to parent route
--app-port <number>              Use a fixed port for the app (skip auto-assignment)
--force                          Override a route registered by another process
--name <name>                    Use <name> as the app name

Environment variables

# Configuration
PORTLESS_PORT=<number>           Override the default proxy port
PORTLESS_APP_PORT=<number>       Use a fixed port for the app (same as --app-port)
PORTLESS_HTTPS=1                 Always enable HTTPS
PORTLESS_TLD=<tld>               Use a custom TLD (e.g. test; default: localhost)
PORTLESS_WILDCARD=1              Allow unregistered subdomains to fall back to parent route
PORTLESS_SYNC_HOSTS=1            Auto-sync /etc/hosts (auto-enabled for custom TLDs)
PORTLESS_STATE_DIR=<path>        Override the state directory

# Injected into child processes
PORT                             Ephemeral port the child should listen on
HOST                             Always 127.0.0.1
PORTLESS_URL                     Public URL (e.g. https://myapp.localhost)

Reserved names: run, get, alias, hosts, list, trust, and proxy are subcommands and cannot be used as app names directly. Use portless run <cmd> to infer the name from your project, or portless --name <name> <cmd> to force any name including reserved ones.

Safari / DNS

.localhost subdomains auto-resolve to 127.0.0.1 in Chrome, Firefox, and Edge. Safari relies on the system DNS resolver, which may not handle .localhost subdomains on all configurations.

If Safari can't find your .localhost URL:

sudo portless hosts sync    # Add current routes to /etc/hosts
sudo portless hosts clean   # Clean up later

Auto-syncs /etc/hosts for custom TLDs (e.g. --tld test). For .localhost, set PORTLESS_SYNC_HOSTS=1 to enable. Disable with PORTLESS_SYNC_HOSTS=0.

Proxying Between Portless Apps

If your frontend dev server (e.g. Vite, webpack) proxies API requests to another portless app, make sure the proxy rewrites the Host header. Without this, portless routes the request back to the frontend in an infinite loop.

Vite (vite.config.ts):

server: {
  proxy: {
    "/api": {
      target: "http://api.myapp.localhost:1355",
      changeOrigin: true,
      ws: true,
    },
  },
}

webpack-dev-server (webpack.config.js):

devServer: {
  proxy: [{
    context: ["/api"],
    target: "http://api.myapp.localhost:1355",
    changeOrigin: true,
  }],
}

Portless detects this misconfiguration and responds with 508 Loop Detected along with a message pointing to this fix.

Development

This repo is a pnpm workspace monorepo using Turborepo. The publishable package lives in packages/portless/.

pnpm install          # Install all dependencies
pnpm build            # Build all packages
pnpm test             # Run tests
pnpm test:coverage    # Run tests with coverage
pnpm lint             # Lint all packages
pnpm typecheck        # Type-check all packages
pnpm format           # Format all files with Prettier

Requirements

Node.js 20+
macOS, Linux, or Windows

Portless

Install / Use

README