It's weird how hard it is to get programmatic access to a mobile-first messaging service. Telegram is the only one that makes it easy. WhatsApp and iMessage have first party solutions that assume you're a business with 1:M comms. Signal doesn't want bot users at all.

Maybe I need to start looking at SMS/MMS proper, but that's putting a lot of information in the clear and giving up a lot of features.

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