Send a number to your menu bar with a link

Great Work — Fri, 30 Oct 2026 07:55:58 GMT

This guide first appeared on multimeterapp.com. Multimeter is a Mac menu bar app that turns any number into a live meter.

Open multimeter://set?key=deploys&value=42 and the Sent Value meter with the key deploys shows 42, right away. If it can open a link, it can update a meter. This works in every version of Multimeter.

Add the meter

Choose Add Meter… from any meter’s menu and pick Sent Value.
In Customize This Meter…, give it a key, like deploys. Keys ignore case.
Send it a value with a link (below). Until the first one arrives the meter says it’s waiting for a value.

Parameters

multimeter://set parameters

Parameter	What it does
`key`	Which meter. Required. Case doesn’t matter.
`value`	The number. Required. The first number in the text is used, so `value=42%25` works.
`min`, `max`	The range, so gauges and bars fill correctly. Default 0 to 100.
`label`	Text for the meter’s label.
`unit`	Shown after the number, like `cups`. Use `%25` (an encoded %) for a percentage.
`formatted`	Your own text, shown instead of the number. The value still drives colors and alerts.

Multimeter remembers the last value for each key, across restarts. Encode spaces as %20.

Recipes

From Terminal or any shell script. -g keeps Multimeter in the background so your focus doesn’t jump:

Terminal

open -g "multimeter://set?key=coffee&value=3&max=5&label=COFFEE"

A small shell function for your ~/.zshrc:

~/.zshrc

mm() { open -g "multimeter://set?key=$1&value=$2"; }
# mm deploys 42

Count uncommitted files after every commit, from a git hook:

.git/hooks/post-commit (make it executable)

#!/bin/sh
n=$(git status --porcelain | wc -l | tr -d ' ')
open -g "multimeter://set?key=dirty&value=$n&label=DIRTY"

From Shortcuts: add a URL action with your link, then Open URLs. Run it from the menu bar, a keyboard shortcut or an automation.

From a Raycast script command: any bash script can run the same open -g line.

From Python and Node:

Python

import subprocess
subprocess.run(["open", "-g", "multimeter://set?key=queue&value=17&max=100"])

Node or Bun

import { spawnSync } from "node:child_process"
spawnSync("open", ["-g", "multimeter://set?key=queue&value=17&max=100"])

Check it worked

Run the Terminal line above with your key. The meter should change within a second, and its menu should show the new value.

Troubleshooting

What the meter says, why, and what to do

Symptom	Cause	Fix
The meter says to give it a key	The Sent Value meter has no key yet.	Set one in Customize This Meter…, the same word you use in key= in the link.
The meter keeps waiting for a value	No link with that key has arrived since the meter was set up, or the keys differ.	Check the spelling of key= against the meter. Case doesn’t matter, spelling does.
macOS asks which app to open the link with, or nothing happens	Multimeter isn’t installed in /Applications or hasn’t been opened yet.	Open Multimeter once, then try again.
Spaces in the label show up as plus signs	The link encoded spaces as +.	Use `%20` for spaces.