2FA codes & OTPs
OTP delivery over SMS is sensitive to timing and number consistency. Shared carrier pools mean codes can arrive from numbers users do not recognise, which increases abandonment. A dedicated SIM with a single, consistent number avoids this.
When a user requests a verification code, your system sends an outbound message request. Relayion dispatches it to the paired device. The SIM sends it. The user receives the code from a number they've seen before, not a rotating short code from a shared pool.
For applications where delivery speed matters, Relayion supports multi-SIM targeting. If you have a second device as a backup, you can target a specific SIM slot or a different device entirely. Your retry logic decides when to fall back and the API supports it either way.
Authentication codes are time-sensitive. Relayion provides webhook events for dispatch, delivery, and failure so your system knows whether the code reached the user or whether a retry is warranted, without polling.
One device, one SIM, one number. No shared infrastructure between your users and anyone else's.
Clinic appointment reminders
Send reminders from the clinic's own number. Patients already have it saved. Replies route back to your system.
Read →AIAI agents that text humans
Give your AI agent a real phone number. Outbound messages and inbound replies flow through the same API.
Read →E-commerceOrder & shipping updates
Confirmations and dispatch notifications from a number your customers recognise. Flat monthly cost.
Read →Ready to connect your first device?
Free plan. One device, 500 messages per month. No credit card required.