Texts from CarbSnap, sent as you.
CarbSnap can text the people around your child — a grandparent, the school nurse, a co-parent — and every text comes from your own number, in the conversation they already have with you. A small menu-bar app on your Mac does the sending, through Messages.
Mac only. CarbSnap Relay runs on a Mac and nothing else. There is no Windows, Linux, iPhone, iPad or Android version, because only Messages on a Mac can send texts as you.
They know it’s you
No unknown number and no short code to ignore. The text lands under your name, in the thread they already read.
Replies come to you
When the nurse answers “got it”, it arrives on your phone like any other text. Nothing in the middle reads it.
There is no other way
Apple offers no service that sends an iMessage as you. Messages on a Mac signed in to your Apple ID is the only thing that can, so that is what CarbSnap uses. No rented number, no SMS company in the middle.
Texts you schedule
Write it on the Texts page, pick who and when. “Spare sensor is in his backpack”, sent at 8 a.m.
Meals, when you ask
Tell your assistant “send that meal to the nurse group tomorrow at 11”. It shows you the exact text first, using your own template, and queues it only when you say so.
Meal links and urgent alerts
Switch them on per person. When a scheduled meal goes out, its link is texted as well as emailed, and so is an urgent alert such as Loop refusing the carbs. A meal link opens only for someone signed in to your CarbSnap, so it is for a co-parent.
Group texts
A group goes out as one Messages group chat, so everyone sees the others and replies go to everyone. Never split into separate texts.
A text says what you wrote, what was eaten and the carbs, or what went wrong. It never carries a dose, and CarbSnap Relay never talks to Loop or the pump.
CarbSnap
Holds the text until it is due. It cannot reach your Mac and does not try.
Your Mac
Asks CarbSnap for anything due every 30 seconds while it is awake, and the moment it wakes.
Messages
Sends it from your Apple ID: by iMessage, or as an SMS through your iPhone.
Their phone
Your Mac reads Messages’ own record to see that it went, then tells CarbSnap.
Your Mac has to be on for this to work
On, awake, and logged in to your account. CarbSnap only holds the texts; your Mac is what sends them. While it is asleep, shut down or at the login screen, nothing goes out.
- A MacBook with its lid closed is asleep, unless it is plugged in and connected to an external display.
- Stop it sleeping on its own: on a MacBook, System Settings → Battery → Options… → Prevent automatic sleeping on power adapter when the display is off. On a desktop Mac, System Settings → Energy → Prevent automatic sleeping when the display is off.
- Turn on Open at login in the app’s menu, so it starts again after a restart.
- A text that comes due while the Mac is asleep goes out when it wakes, unless its deadline has passed: 2 hours for a meal text, 12 for one you wrote unless you chose otherwise. After that it is dropped rather than sent late.
A Mac that stays plugged in and awake, such as a desktop or a MacBook on a charger, is the reliable choice.
iMessage: your Mac alone
To anyone with an iPhone, iPad or Mac. Your Mac sends it over the internet by itself. Your iPhone is not involved and can be anywhere, even switched off.
Needs Messages on the Mac signed in with your Apple ID: in Messages, open Messages → Settings → iMessage.
SMS: through your iPhone
For Android phones, or whenever iMessage fails. A Mac cannot send an SMS itself, so Messages passes it to your iPhone, which sends it over its own cell signal.
Your iPhone does not need to be near your Mac. It needs to be switched on, have cell signal, be online (Wi-Fi or cellular data), and be signed in to the same Apple ID as the Mac. If it is off or has no signal, the text cannot go, and the Texts page shows it as failed or not confirmed rather than sent.
- On your Mac, open Messages and check it is signed in with the same Apple ID as your iPhone (Messages → Settings → iMessage).
- On your iPhone, open Settings → Apps → Messages → Text Message Forwarding.
- Switch on your Mac in that list. If your iPhone shows a code, type it into the Mac.
- Test it: from Messages on the Mac, send a text to an Android phone, or to any number with iMessage turned off. A green bubble means SMS works.
CarbSnap Relay always tries iMessage first. It switches to SMS only when Messages records that the iMessage failed, or will not take the text at all. Nothing else is needed; once forwarding is on, the backup is automatic.
It asks for Full Disk Access, and that is a big ask, so here is exactly why. Messages keeps its record of what was sent in a database only Full Disk Access can open. Reading it is how the app knows a text actually went, instead of guessing and risking a second copy.
It reads only messages you sent, only to the person or group it just texted, and only from the moment it handed the text over. It never reads messages sent to you. The only things that leave your Mac are whether the text went, which service carried it, Messages’ ID for that one text, and Messages’ error if it gave one.
- Download it and drag it into Applications Open the disk image, drag CarbSnap Relay onto the Applications folder, then open it from Applications. Its mark, two brackets around a lens, appears in the menu bar, and a window opens until you have signed in. If you had an older copy running, quit it from its menu first.
- Sign in to CarbSnap Click the mark, then Sign in to CarbSnap. Your browser opens; sign in as usual, check the code matches the one in the app, and approve. Nothing to copy.
- Give it Full Disk Access The app shows a button that opens the right page of System Settings. Switch CarbSnap Relay on there, then choose Reopen CarbSnap Relay.
- Check Messages, and turn on SMS backup Messages on this Mac must be signed in to your Apple ID. For Android phones, turn on Text Message Forwarding on your iPhone; the steps are above.
- Approve the first text macOS asks once whether CarbSnap Relay may control Messages; allow it. Then the app asks you to approve each new number as it comes up.
Does it work on Windows, iPhone or Android?
No. CarbSnap Relay is a Mac app and needs a Mac signed in to Messages. Apple lets nothing else send iMessages or texts from your number. CarbSnap itself works in any browser; only the texting needs the Mac.
I can’t see the icon in my menu bar
On a MacBook, macOS hides menu bar icons that don’t fit beside the camera notch, even though the app is running. Open CarbSnap Relay again from Applications and its window appears. To get the icon back, hold ⌘ and drag other icons out of the menu bar, or turn some off in System Settings → Menu Bar.
Will it ever text someone I didn’t add?
It would take two things going wrong at once: CarbSnap asking for a number you never added, and you clicking Allow on your own Mac for a number you do not recognise. Remove a number from the app’s Settings and it asks again next time.
Can other people in my care circle send texts as me?
Only to the people you added. A caregiver you invite can ask their assistant to send a meal text, or change or cancel one that is scheduled, and it goes from your number to the people and groups you set up. They cannot open the Texts page, add anyone or pair a Mac, and your Mac still asks you before it texts any number for the first time.
How do I pause or stop it?
Pause is in the menu. Unpair on the Texts page cuts the Mac off from CarbSnap; it is refused from its next check. To remove it entirely, quit it from the menu, drag it from Applications to the Trash, and remove it from Full Disk Access in System Settings.
Why isn’t it on the Mac App Store?
Every App Store app runs in Apple’s sandbox, and a sandboxed app can never read Messages’ database. Without that it could not tell whether a text went. It is distributed the other way Apple supports: signed with a Developer ID and notarized.
How does it update?
By itself, from version 1.0.2. Every few hours it asks this site whether a newer version is out, and Check for Updates in the menu asks straight away. A new version downloads, replaces the app in Applications and restarts it, with nothing to drag. Before anything is replaced, it checks that the download is signed by CarbSnap, has passed Apple’s notarization check, and matches the checksum this site published. It waits until no text is being sent, shows a window while it updates and a confirmation once it has, and your permissions carry over. Switch Install updates automatically off in Settings if you would rather click Install yourself. Copies older than 1.0.2 need one last download from this page.
CarbSnap is not a medical device. CarbSnap Relay sends text messages and nothing else. Privacy · Terms · What CarbSnap does