Skip to content
trop

Overview

trop assigns port numbers to directories. It is useful when you run development servers in several worktrees and want each one to keep its own port.

Terminal window
PORT=$(trop reserve) &&
  npm run dev -- --port "$PORT"

This example assumes an npm dev script that accepts --port. trop reserve prints the port to stdout; diagnostics go to stderr. The && starts the server only if the reservation succeeds.

Model

Section titled “Model”

A reservation is a record in a local SQLite database, keyed by a directory and an optional tag:

  • Repeating trop reserve in the same directory returns the stored port.
  • A different directory or tag gets a separate reservation.
  • Reservations persist when a server stops. Release or prune them when you no longer need them.

Any directory works; it does not have to be a Git worktree. Concurrent callers coordinate through the same database, stored in ~/.trop by default.

The record does not hold a socket open or prevent another program from taking the port. See Scope for the limits, or Usage for installation and commands.