# WhatThePort > Every dev server on your Mac, in the menu bar. WhatThePort is a free, open-source macOS menu bar app that shows what’s running on localhost: each dev server’s port, project, git branch, uptime, memory and CPU, and the Claude Code, Codex or Conductor session that started it. Stop the ones you forgot about in one click. - Website and interactive demo: https://whattheport.dev - Download (Apple Silicon, macOS 14 or later): https://whattheport.dev/WhatThePort.dmg - Source code (MIT): https://github.com/tomjohndesign/what-the-port - Guides: https://whattheport.dev/guides - Price: free. No account. - Made by Tom John (https://tomjohn.design) ## What it does - **Every dev server at a glance.** Port, project name, git branch, uptime and memory for each local server, with stable port colors and a whole-Mac memory bar for servers, other apps and free RAM. - **Knows which agent started it.** Servers launched by Claude Code, Codex or Conductor link back to the session that started them, so you can resume the conversation (`claude --resume`, `codex resume`) or find the Conductor workspace. - **Leak detection.** When a server passes 2 GB of memory or grows more than 500 MB in ten minutes, its memory reading and the menu bar icon turn amber and you get one notification with Details, Stop and Snooze. Thresholds are adjustable. - **Resource charts.** Ten minutes of memory and CPU history per server, summed across its whole process tree. - **Clean up.** Preselects servers from deleted git worktrees or idle for hours, then stops each whole process tree in bulk. Postgres, Redis, MongoDB and MySQL are protected by default. Cleanup can be Off, Ask or Automatic; leaking servers are never stopped automatically. - **Stop and restart.** Stop sends SIGTERM to the whole process tree, then SIGKILL after a short delay. Restart reruns the original command in the same folder. - **Previews and pull requests (optional).** A Vercel preview button and the branch’s pull request, through the GitHub CLI you’re already signed in to. - **Terminal UI.** `wtp` shows the same servers, details and Clean up in your terminal. `wtp list --json` prints them as JSON for scripts and coding agents. - **Global shortcut.** ⌥⌘P opens the popover. - **Native.** Written in Swift. No Electron, no Dock icon. Light and dark mode. ## Install 1. Download https://whattheport.dev/WhatThePort.dmg and open it. 2. Drag WhatThePort onto the Applications shortcut, then open it from Applications. 3. Start a dev server, then click the dot grid in the menu bar or press ⌥⌘P. The prebuilt download is for Apple Silicon Macs running macOS 14 Sonoma or later. Updates are signed and install automatically when you quit. To build from source you need Swift 5.9 or later: `cd WhatThePort && swift build`. ## The wtp command Onboarding offers to install `wtp`, or click Install… in Settings → General → Terminal. It links `/usr/local/bin/wtp` to the app. ``` wtp Browse, open and stop servers wtp list Print servers and exit wtp list --json Print servers as JSON wtp --version Print the version ``` `wtp list --json` prints an array of servers. Each has `port`, `url`, `pid`, `name`, `branch`, `framework`, `folder`, `command`, `startedAt`, `memoryBytes`, `cpuPercent`, `status` (`running`, `attention` or `idle`), `protected`, `processes` and, when an agent started it, `session` (`kind`, `id`, `title`). ## How it works WhatThePort reads listening TCP sockets with `lsof`, then inspects each server’s process tree through `libproc` and `sysctl`: memory footprint, CPU time, working directory, arguments and environment. From the working directory it finds the project manifest (package.json, pyproject.toml, Cargo.toml, go.mod, Gemfile), framework and git branch. Session links come from environment variables that Claude Code and Conductor pass to the commands they run, and from Codex’s session files. It rescans every 2 seconds. By default it watches ports 3000–65535 and processes that look like dev servers: node, bun, deno, python, uvicorn, gunicorn, ruby, rails, puma, php, java, go, cargo, dotnet, elixir, nginx, postgres, redis, mongod, mysql and more. Both are configurable in Settings → Ports & processes. Frameworks it recognizes include Next.js, Nuxt, Remix, Astro, SvelteKit, Vite, Expo, Angular, Create React App, Hono, Express, Storybook, Django, FastAPI, Flask, Rails, Rust and Go. ## Privacy There’s no account and no analytics SDK. Everything the app shows comes from your Mac and stays there. It only goes online to check for updates, to send an anonymous once-a-day count of which features were used (no identifiers, and you can turn it off), and, if you turn them on, to look up Vercel previews and pull requests through the GitHub CLI. ## FAQ ### Is WhatThePort free? Yes. It’s free and open source under the MIT license, with no account and no paid tier. There’s an optional tip jar. ### Does it work on Intel Macs or older macOS? The prebuilt download is for Apple Silicon Macs on macOS 14 Sonoma or later. You can build it from source with Swift 5.9 or later. ### How is it different from `lsof` or `npx kill-port`? Those answer one question about one port. WhatThePort keeps every dev server in view all the time, names them by project and branch, shows memory and CPU for the whole process tree, warns you about leaks, links servers to the agent session that started them, and stops the whole tree, not just one PID. ### Will it stop my database? Not unless you choose to. Postgres, Redis, MongoDB and MySQL are protected from Clean up by default, and you can edit the protected list. ### Can a coding agent use it? Yes. `wtp list --json` gives agents a machine-readable list of every server, its port, folder, branch, status and the session that started it, so an agent can reuse a running server instead of starting a duplicate on the next port. ### Where is the menu bar icon? It’s a small 5×5 dot grid showing a colon. If the menu bar is full, macOS hides icons that don’t fit: click » at its edge on macOS 27, or check System Settings → Menu Bar. Opening WhatThePort again from Finder or Spotlight shows the popover.