How SM Text works
Six steps from empty account to texting and calling from your browser.
1 · Create your account
Register with your email and password, then verify your email to unlock your dashboard — that takes one click on the link we send.
Your account starts as a customer role. Everything is protected by signed sessions and role checks.
2 · Top up prepaid credit
Choose BTC, ETH, USDT, or USDC at Billing → Add credit. We generate a deposit address and quote an exact asset amount, locked for 30 minutes.
Credit lands after on-chain confirmations. The minimum top-up is $10.00 — there is no free trial credit.
3 · Pick your US number
Search the marketplace by area code, prefix, or city and filter by SMS/voice capability. Checkout shows the setup fee plus the first month before you confirm.
Numbers are US-only. Local and toll-free types are both available.
4 · Pay with crypto
Send the exact amount to your deposit address. When confirmations land, the order is marked paid — the number never activates before payment is confirmed.
Every payment is idempotent: a repeated confirmation cannot double-charge or double-activate.
5 · Number goes live
After payment, the number is provisioned automatically and appears under My Numbers with its own SMS identity and inbox.
If provisioning ever fails, the order is flagged for automatic retry — you are never charged for an unprovisioned number.
6 · Text and call in the browser
Open Messages for a Messenger-style inbox or Calls for the dial pad. Incoming texts arrive in realtime; incoming calls pop an answer/reject screen.
Calling uses WebRTC in your browser — no mobile app, no SIM, no desk phone.
Under the hood
Inbound SMS path
Recipient's phone → carrier → SM Text provider webhook (signature-verified) → your inbox updates in realtime.Outbound SMS path
Your composer → SM Text API (balance check) → carrier → recipient → delivery receipt updates the status tick.Browser calling path
Dial pad → SM Text voice API (short-lived browser token) → carrier → callee. Media flows over WebRTC, credentials never touch your device.