vercel-labs-portless

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

Global (recommended):

npm install -g portless

Or as a project dev dependency:

npm install -D portless

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.

Run your app

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

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, TLDs) 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.

Configuration

Bare portless works out of the box. It runs the "dev" script from package.json through the proxy, inferring the app name from the package name, git root, or directory:

portless        # -> runs "dev" script, https://<project>.localhost

Use an optional portless.json to override defaults:

{ "name": "myapp" }

portless        # -> runs "dev" script, https://myapp.localhost

The script defaults to "dev". The name is inferred from package.json if not set in config.

Monorepo

One portless.json at the repo root covers all workspace packages. Portless discovers packages from pnpm-workspace.yaml, or the "workspaces" field in package.json (npm, yarn, bun):

{
  "apps": {
    "apps/web": { "name": "myapp" },
    "apps/api": { "name": "api.myapp" }
  }
}

portless        # from repo root: starts all workspace packages with a "dev" script
cd apps/web && portless   # start just one package

The apps map is optional and only needed for name overrides. Packages not listed still auto-discover with names inferred from their package.json.

Without an apps map, hostnames follow the <package>.<project>.localhost convention. The project name comes from the most common npm scope across workspace packages (e.g. @myorg/web and @myorg/api produce myorg), falling back to the workspace root directory name. If a package's short name matches the project name, it gets the bare <project>.localhost without duplication.

Config fields

Field	Type	Default	Description
name	string	inferred	Base app name. Worktree prefix still applies.
script	string	"dev"	Name of a package.json script to run.
appPort	number	auto	Fixed port for the child process.
proxy	boolean	auto	Whether to route through the proxy. Auto-detected.
apps	object		Overrides for workspace packages, keyed by relative path.
turbo	boolean	true	Set false to use direct spawning instead of turborepo.

package.json "portless" key

Instead of a separate portless.json, you can add a "portless" key to your package.json. A string value is shorthand for setting the name:

{
  "name": "@myorg/web",
  "portless": "myapp"
}

An object supports all per-app fields (name, script, appPort, proxy):

{
  "name": "@myorg/web",
  "portless": { "name": "myapp", "script": "dev:app" }
}

The package.json "portless" key takes precedence over portless.json app entries but is overridden by CLI flags.

--script flag

Override the default script for a single invocation:

portless --script start       # run "start" instead of "dev"
portless --script test        # run "test" instead of "dev"

Turborepo

To use portless with turborepo, put portless as the dev script and the real command in a separate script: