Sparetext

Can an iPhone be an SMS gateway?

Yes, within what Apple allows. No iPhone app can send or read SMS silently, so Sparetext uses the three paths iOS does allow. A Mac relay sends and reads texts from the iPhone's own number, fully automatically. A Shortcut sends automatically while the Sparetext app is open. Or the app opens each text for you to tap Send.

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Why apps can't just send texts on an iPhone

iOS has no API that lets an app send an SMS without a person pressing Send, or read the texts that arrive. That rules out the way Android gateways work, where an app hands texts to the radio in the background. Any iPhone tool that claims silent sending from the phone alone is either using the user's tap or not sending from the phone.

1. The Mac relay: fully automatic

Your iPhone already forwards its texts to your Mac when Text Message Forwarding is on. Sparetext for Mac (or the sparetext command-line relay) sends queued texts through the Messages app, so they leave from the iPhone's own number, and it reads replies and send errors from Messages' database. The Mac has to be awake and signed in to Messages, and the iPhone switched on with a connection.

  1. On the iPhone: Settings › Apps › Messages › Text Message Forwarding, and turn on the Mac.
  2. In the dashboard: Phones › Add phone › iPhone + Mac relay, then pair Sparetext for Mac with the code.
  3. Give it Full Disk Access, so it can read replies, and allow it to control Messages on the first send.

2. The Shortcut: automatic while the app is open

The Sparetext iPhone app keeps the screen awake and runs the "Sparetext Send" shortcut for each batch, which sends with the system Send Message action. It suits a spare iPhone left on a charger. With "Send while locked", a Shortcuts automation started by a wake email or notification sends while the phone is locked.

3. Tap to send: any iPhone

The app opens each queued text in the system composer with the number and words filled in, and you tap Send. Nothing to set up, and nothing goes out without you.

What an iPhone can't do that Android can

Delivery reports: an iPhone or Mac reports sent or failed, but carriers' delivered receipts reach only Android. Reading replies: the Mac relay reads them; on the iPhone alone, a "When I get a message" automation with the Forward Text to Sparetext action passes them on. Unattended sending without a Mac: only while the app is open, or through the Send while locked automation.

Questions people ask

Can I use my iPhone as an SMS gateway without a Mac?
Yes, with the Sparetext iPhone app: it sends automatically while the app is open (a spare iPhone on a charger works well), or by a Shortcuts automation while the phone is locked, or you tap Send for each text. For fully automatic sending with the screen off and replies read back, add a Mac.
Do texts come from my iPhone's number?
Yes. All three paths send from the iPhone's own number: the Mac relay through Text Message Forwarding, the others from the phone itself.
Can it send iMessage?
The Mac relay sends SMS by default and can send as iMessage, or try SMS first and fall back to iMessage. The Shortcut and tap to send use whatever Messages picks.
Can an AI agent text from my iPhone?
Yes. Connect Claude, ChatGPT or another MCP client to Sparetext; the agent queues the text and the iPhone sends it by whichever path you set up.