What you need
- Multimeter for macOS 13 or later, $19.99 once.
- A Nightscout site.
- A read-only access token: in Nightscout, Admin Tools, add a subject with the role
readable, and copy its token (it looks likemultimeter-4e736d5a5653f513).
Set it up
- Check it in Terminal with your site and token:Terminal
curl -s 'https://YOUR-SITE/api/v1/entries/current.json?token=YOUR-TOKEN' - Add a Web Address meter with that address and the key path
0.sgv. Refresh every minute. - Set the range to 40 to 300 and the unit to
mg/dL. Alerts work in one direction per meter: Low values with warning 80 and critical 70 is the usual choice. Add a second meter on the same address for highs if you want both.
Multimeter settings
In Customize This Meter… (from the meter’s menu):
| Setting | Value |
|---|---|
| Source | Web Address |
| Web address | https://YOUR-SITE/api/v1/entries/current.json?token=YOUR-TOKEN |
| Key path | 0.sgv |
| Refresh every | 1 minute |
| Range | 40 to 300 |
| Unit | mg/dL |
| Alerts | Low values: warning 80, critical 70 |
| Label | BG |
| Face | Sparkline, Label & Value or Gradient Track |
Tested: Run on October 29, 2026 against Nightscout (cgm-remote-monitor) in Docker with a readable token: 0.sgv returned 142; without the token it answered 401.
More on this source, including every format it reads, in the Web Address guide.
Limits
- The reading is as fresh as your uploader. CGMs report every 5 minutes; refreshing every minute catches each new one quickly.
- The token is in the address, so anyone who sees your Multimeter settings sees it. It is read-only.
Variations
mmol/L
Use https://YOUR-SITE/pebble?units=mmol&token=YOUR-TOKEN with the key path bgs.0.sgv, range 2 to 17, unit mmol/L.
The change since the last reading
Same pebble address, key path bgs.0.bgdelta.
Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| No number found in the response | The key path doesn’t match the reply. | Run curl -s with the address and read the JSON. Dots walk into objects, numbers pick array items (items.0.count). |
| Couldn’t reach the address | No network, a typo in the host, or the service is down. | Open the address in your browser. Multimeter tries again at the next refresh. |
| The server answered 401 | The token is missing or wrong, or the subject doesn’t have the readable role. | Copy the token again from Admin Tools; the whole thing, including the name before the dash. |
Questions
Does it work with Dexcom or Libre directly?
Through Nightscout. Most CGMs can upload to Nightscout with xDrip+, Loop, AndroidAPS or a Dexcom Share bridge.
Can it alert me?
It colors the meter and can send a notification when it goes critical, at most every 15 minutes. It isn’t a replacement for your CGM’s alarms.