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

npm install -g portless

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

# 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), portless auto-injects --port and --host flags.

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

Organize services with subdomains:

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

Wildcard subdomain routing: any subdomain of a registered route routes to that app automatically (e.g. tenant1.myapp.localhost:1355 routes to the myapp app without extra registration).

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.

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).

flowchart TD Browser["Browser\nmyapp.localhost:1355"] Proxy["portless proxy\n(port 1355)"] App1[":4123\nmyapp"] App2[":4567\napi"] Browser -->|port 1355| Proxy Proxy --> App1 Proxy --> App2 

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

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).

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 stop # Stop the proxy

-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) --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 

# 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_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, 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.

.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.

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.

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

• Node.js 20+
• macOS or Linux