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/portless

Set up and use portless for named local dev server URLs (e.g. https://myapp.localhost instead of http://localhost:3000). Use when integrating portless into a project, configuring dev server names, setting up the local proxy, working with .localhost domains, or troubleshooting

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portless
10k2 skills
Install
$ npx -y skills add vercel-labs/portless --skill portless --agent claude-code

How it fires

How this skill gets triggered: by you, by Claude, or both.

  • Fires itselfAuto-invocation. Claude auto-loads it when your prompt matches the work.Auto-invocation is when the right skill fires by itself at the right moment, driven by a FLOW.md router and a hook, instead of you invoking it by name. It is the difference between a skill being installed and a skill actually getting used.Read the full definition →
  • You can call itInvoke it directly when you want it.
  • Slash command/portless

Context preview

The summary Claude sees to decide when to auto-load this skill.

Set up and use portless for named local dev server URLs (e.g. https://myapp.localhost instead of http://localhost:3000). Use when integrating portless into a project, configuring dev server names, setting up the local proxy, working with .localhost domains, or troubleshooting

SKILL.md

portless.SKILL.md
name: portless
description: Set up and use portless for named local dev server URLs (e.g. https://myapp.localhost instead of http://localhost:3000). Use when integrating portless into a project, configuring dev server names, setting up the local proxy, working with .localhost domains, or troubleshooting port/proxy issues.

Portless

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

Why portless

  • **Port conflicts**: `EADDRINUSE` when two projects default to the same port
  • **Memorizing ports**: which app is on 3001 vs 8080?
  • **Refreshing shows the wrong app**: stop one server, start another on the same port, stale tab shows wrong content
  • **Monorepo multiplier**: every problem scales with each service in the repo
  • **Agents test the wrong port**: AI agents guess or hardcode the wrong port
  • **Cookie/storage clashes**: cookies on `localhost` bleed across apps; localStorage lost when ports shift
  • **Hardcoded ports in config**: CORS allowlists, OAuth redirects, `.env` files break when ports change
  • **Sharing URLs with teammates**: "what port is that on?" becomes a Slack question
  • **Browser history is useless**: `localhost:3000` history is a mix of unrelated projects

Installation

Install globally (recommended) or as a project dev dependency. Do NOT use `npx` or `pnpm dlx` for one-off execution.

# Global (available everywhere)
npm install -g portless

# Or per-project dev dependency
npm install -D portless

When installed per-project, invoke via package.json scripts or `npx portless` (since the package is local, npx will not download anything).

Quick Start

# Install globally (or add -D to a project)
npm install -g portless

# Run your app (auto-starts the HTTPS proxy on port 443)
portless run next dev
# -> https://<project>.localhost

# Or with an explicit name
portless myapp next dev
# -> https://myapp.localhost

The proxy auto-starts when you run an app. You can also start it explicitly with `portless proxy start`. Auto-start 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 always take priority.

In non-interactive environments (no TTY, or `CI=1`), portless exits with a descriptive error instead of prompting. Task runners like turborepo should pre-start the proxy.

Integration Patterns

Zero-config (recommended)

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
pnpm dev        # -> works without portless, plain "next dev"

Use an optional `portless.json` to override defaults (name, script, port):

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

Monorepo

One `portless.json` at the repo root. 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: start all packages with a "dev" script
cd apps/web && portless   # start just one package
portless --script start   # run "start" instead of "dev"

The `apps` map is optional and only provides name overrides. Unlisted packages auto-discover with inferred names.

Without an `apps` map, hostnames follow `<package>.<project>.localhost`. The project name comes from the most common npm scope (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 uses the bare `<project>.localhost`.

Turborepo

For turborepo projects, use portless as the `dev` script with the real command in a separate script:

{
  "scripts": { "dev": "portless", "dev:app": "next dev" },
  "portless": { "name": "myapp", "script": "dev:app" }
}

`pnpm dev` runs turbo, which runs `portless` in each package. Portless detects the package manager and runs `pnpm run dev:app` through the proxy.

package.json scripts

You can still use portless directly in scripts:

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

The proxy auto-starts when you run an app. Or start it explicitly: `portless proxy start`.

Multi-app setups with subdomains

portless myapp next dev          # https://myapp.localhost
portless api.myapp pnpm start    # https://api.myapp.localhost
portless docs.myapp next dev     # https://docs.myapp.localhost

By default, only explicitly registered subdomains are routed (strict mode). Start the proxy with `--wildcard` to allow any subdomain of a registered route to fall back to that app (e.g. `tenant1.myapp.localhost` routes to the `myapp` app). Exact matches always take priority over wildcards.

Git worktrees

`portless run` automatically detects git worktrees. In a linked worktree, the branch name is prepended as a subdomain prefix so each worktree gets a unique URL:

# Main worktree (no prefix)
portless run next dev   # -> https://myapp.localhost

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

No config changes needed. Put `portless run` in `package.json` once and it works in all worktrees.

Bypassing portless

Set `PORTLESS=0` to run the command directly without the proxy:

PORTLESS=0 pnpm dev   # Bypasses proxy, uses default port

How It Works

1. `portless proxy start` starts an HTTPS reverse proxy on port 443 as a background daemon. Auto-elevates with sudo on macOS/Linux; falls back to port 1355 if sudo is unavailable. Use `--no-tls` for plain HTTP on port 80. Configurable with `-p` / `--port` or the `PORTLESS_PORT` env var. The proxy also auto-st

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Ships withportless

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

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Apache-2.0
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11d ago
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Repo: vercel-labs/portless