vercel-labs/portless

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

Or as a project dev dependency:

portless is pre-1.0. When installed per-project, different contributors may run different versions. The state directory format may change between releases, which can require re-running portless trust.

HTTPS with HTTP/2 is enabled by default. On first run, portless generates a local CA, trusts it, and binds port 443 (auto-elevates with sudo on macOS/Linux). Use --no-tls for plain HTTP.

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, VitePlus, Astro, React Router, Angular, Expo, React Native), portless auto-injects the right --port flag and, when needed, a matching --host flag.

When auto-starting, portless reuses the configuration (port, TLS, TLD) from the most recent proxy run, so a restart or reboot does not silently revert to defaults. Explicit env vars (PORTLESS_PORT, PORTLESS_HTTPS, etc.) always take priority.

In non-interactive environments (no TTY, or CI=1), portless exits with a descriptive error instead of prompting, so task runners like turborepo and CI scripts fail early with a clear message.