WHOSEPORT
Investigations · guide

Port in use

EADDRINUSE, or a dev server that comes up on the wrong port. Find what holds the port and who started it.

Ask

bash
whoseport 3000

What WhosePort checks

  • Listener on the port and its PID
  • Process command, parent chain, cwd and start time
  • Project and Git branch or worktree for the cwd
  • HTTP health of whatever answers on the port

Typical root cause

Usually a dev server from a previous session, or a second copy started in another worktree.

Proposed fix

  • stop_process on the stale PID (approval required)
  • Or keep both and start the new server on the next free port
Approval
Every step that changes your machine is a typed action classed by the policy engine. It waits for your approval in the dashboard, which shows the target, risk and expected effect first. A changed .env file is backed up before it is written. See /docs/policy.

Verification

  • Port is free, or the intended process now owns it
  • New server answers over HTTP