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portless-local

Replace port numbers with stable named .localhost URLs for local development

Skill by jellydn

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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

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About

Replace port numbers with stable named .localhost URLs for local development

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What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

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  • codeload.github.com · found in install command

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  • ~/.claude/skills/portless-local

What's inside

Skill name
portless-local
Description
Replace port numbers with stable named .localhost URLs for local development
License
MIT
Compatibility
cline, claude, opencode, amp, codex, gemini, cursor, pi
Metadata
source: vercel-labs/portless@7abf4df5d939fe3b527a120e20bc270c681c3536 · audience: all · workflow: development · source_path: skills/portless/SKILL.md
Instructions
472 lines in SKILL.md · view on GitHub

Files (1)

  • SKILL.md

SKILL.md (first lines)

# Portless - Named .localhost URLs

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

> **Note:** The portless CLI enables HTTPS on port 443 by default (`https://myapp.localhost`). Pass `--no-tls` to `portless proxy start`, or set `PORTLESS_HTTPS=0`, for plain HTTP. Keep HTTPS when the app needs OAuth, secure cookies, or HTTP/2.

## Safety and Approval

Read existing proxy configuration before starting an app: auto-start reuses saved settings, including LAN mode. Outside LAN mode the proxy binds only to IPv4/IPv6 loopback; LAN mode binds all interfaces.

Ask for explicit approval before first-run sudo/elevation, CA trust-store changes, `/etc/hosts` writes, LAN exposure, Tailscale sharing, public Funnel/ngrok tunnels, startup-service installation/removal, or destructive cleanup. A request for local development does not authorize these actions. Use `PORTLESS_SYNC_HOSTS=0` when hosts writes are not approved. In non-interactive environments, first-run prompts fail rather than granting permission; pre-start only an approved proxy configuration.

`--force` kills the existing process and takes over its route. `prune` terminates orphaned process groups, and `prune --force` uses SIGKILL. Do not use them without checking ownership and approval. `clean` also removes startup services and trust entries; it is not routine project cleanup.

Never print or commit TLS private keys or ngrok tokens. Let the user configure authentication through the provider's private credential workflow. Do not disable TLS verification to resolve proxy errors.

## Why Portless?

Local dev with port numbers is fragile. Portless fixes that by giving each dev server a stable, named `.localhost` URL.

| Problem                    | With Ports                                              | With Portless                                   |
| -------------------------- | ------------------------------------------------------- | ----------------------------------------------- |
| **Port conflicts**         | Two projects on :3000 = EADDRINUSE                      | Auto-assigned ports, named URLs - no collisions |
| **Memorizing ports**       | "Was the API on 3001 or 8080?"                          | Always `https://api.localhost`                   |
| **Wrong app on refresh**   | Stop one server, start another on same port = confusion | Named URLs eliminate this                       |
| **Monorepo chaos**         | Every service needs a unique port                       | Distinct hostnames for each service             |
| **Agent confusion**        | AI agents guess/hardcode wrong ports                    | `https://myapp.localhost` is deterministic       |
| **Cookie/storage clashes** | Cookies bleed across ports on localhost                 | Each `.localhost` subdomain gets its own scope  |
| **Hardcoded config**       | CORS, OAuth, .env break when ports change               | URLs are stable across restarts                 |
| **Sharing URLs**           | "What port is that on?" in Slack                        | Everyone uses the same named URL                |
| **Browser history**        | `localhost:3000` history is a jumble                    | Named URLs keep things organized                |

## Installation

```bash
# Global (recommended)
npm install -g portless

# Or as a project dev dependency
npm install -D portless
```

Requires Node.js 24+ and OpenSSL for certificate generation. Install globally or as a project dependency; do not use a one-off `npx`/`pnpm dlx` download. A local package may be invoked through package scripts or `npx portless` without downloading it.

## Usage

Invoke via skill command or use CLI directly:

```bash
# Via skill command
/portless-local <NAME> <COMMAND> [OPTIONS]

# Or use CLI directly
portless <NAME> <COMMAND> [OPTIONS]
```

## Commands

### Run an App

```bash
portless run [--name <name>] <cmd> [args...]   # Infers name from package.json, git root, or directory
portless <name> <cmd> [args...]                # Explicit name, no inference
```

`portless run` infers the project name from package.json, git root, or directory name. Use `--name` to override the inferred name while still applying worktree prefixes.

| Flag                  | Description                                                                                         |
| --------------------- | --------------------------------------------------------------------------------------------------- |
| `--name <name>`       | Override the inferred base name (worktree prefix still applies). Only for `portless run`.           |
| `--app-port <number>` | Use a fixed port for the app instead of auto-assignment. Also configurable via `PORTLESS_APP_PORT`. |
| `--force`             | Kill the existing process and take over its route; requires ownership checks and approval           |

**Examples:**

```bash
portless run next dev                    # Infer name from project
portless run --name myapp next dev       # Override inferred name
portless myapp next dev                  # Explicit name
portless api pnpm start                  # API service
portless docs.myapp next dev             # Subdomain
```

### Get a Service URL

```bash
portless get <name>
```

Print the URL for a service. Useful for wiring services together in scripts or env vars:

```bash
BACKEND_URL=$(portless get backend)
```

Applies worktree prefix detection by default. Use `--no-worktree` to skip it.

### Alias (Static Routes)

```bash
portless alias <name> <port>              # Register a static route
portless alias <name> <port> --force     # Force override existing
portless alias --remove <name>            # Remove the alias
```

Register a route for a service not managed by portless (e.g. a Docker container). Aliases persist across stale-route cleanup.

```bash
portless alias my-postgres 5432     # -> https://my-postgres.localhost
portless alias redis 6379           # -> https://redis.localhost
portless alias --remove my-postgres # Remove the alias
```

### List Routes

```bash
portless list
```

From jellydn/my-ai-tools, MIT.

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Last commit (this folder)
Oct 7, 2026 (21 days ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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portless-local skill. Agent Mart. https://agentmart.dev/skills/jellydn-portless-local (last updated 2026-10-24)