portless

portless is a skill for Claude Code, Codex from tutur3u/platform. It costs 67 tokens per session (5,860 once invoked), scanned B, original, Apache-2.0.

A local-development tool that gives web applications stable names such as `https://myapp.localhost` instead of numbered addresses such as `http://localhost:3000`. It includes setup and troubleshooting for the local proxy and named development servers.

In plain words
What is it for?
Use it to name local apps, run several services in a monorepo—a repository containing multiple related projects—avoid shared cookies and storage, and keep CORS or OAuth settings stable.
Why use it?
It reduces port conflicts, confusion between projects, browser mix-ups, and configuration problems caused by changing port numbers.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/tutur3u/platform/portless
Any agent
npx skills add tutur3u/platform --skill portless
Clone the repo
git clone --depth 1 https://github.com/tutur3u/platform

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for portless

README.md
[![agentmods](https://agentmods.dev/badge/skills/tutur3u/platform/portless.svg)](https://agentmods.dev/skills/tutur3u/platform/portless)
Your own site
<a href="https://agentmods.dev/skills/tutur3u/platform/portless"><img src="https://agentmods.dev/badge/skills/tutur3u/platform/portless.svg" alt="Measured on agentmods" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,860 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00067 $0.05860
Opus 5 $0.00034 $0.02930
Sonnet 5 $0.00013 $0.01172
Haiku 4.5 $0.00007 $0.00586

Measured 6d ago against content hash f51180c37bc4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade B, and why

portless scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

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
.agents/skills/portless/SKILL.md · 469 lines

How it starts

The opening of the file, as written. The whole thing — 469 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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, TLD) 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.

Read the full file on GitHub · 469 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 469 lines · 67 tokens per session scan B f51180c37bc4

Subscribe to this mod's changes

portless is a skill published in the GitHub repository tutur3u/platform (53 stars, last pushed yesterday), licensed Apache-2.0. It adds 67 tokens to every session and 5,860 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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