SMS API for Developers
Send or receive SMS and MMS globally with Zernio Messaging API
Your order #4821 has shipped 📦
Track it: acme.co/t/4821
Wait, that's my old address 😬
Yes! You can change the shipping address.
- SMS + MMS
- 10DLC handled
- Replies in one Inbox
Trusted by developers at
SMS in more than one country
Send from your own numbers across the US, Canada, Europe, and beyond in one API
United States
Canada
United Kingdom
Australia
Belgium
Lithuania
Netherlands
Poland
Puerto Rico
Sweden
South Africa
Virgin Islands
From number to first SMS in three steps.
1United States local number
$3/mo
Calls included. Inbound and outbound, live from day one.
WhatsApp ready.Connect it anytime from the number's row.
SMS capable. Enable texting whenever you need it.
Get number
Purchase or port SMS number
Buy or port number(s) with SMS capability. Search with sms=true, or enable it on a number you already have.
2+1 618 575 1022
ActiveSMS
OffTexts United States numbers only (no international SMS)
Picture & media messages (MMS) supported
Turn on SMS
Calls & Voicemail
OnNo forward set — inbound calls go to voicemail.
Call recording off
No transcription
Voicemail on
Call settings
Turn off calls
Register
Enable SMS, then start a 10DLC or toll-free registration. Already approved? Attach the new number to the existing campaign and skip the fee. Outside the US, skip this step.
3Messages
Conversations
34647509795 · via +1 707 605 9837
All works!
Amirah Temitope via +1 707 605 9837
Hey! 👋 Zernio is a social media scheduling and inbox API that...
Send
Send a message with text, mediaUrls, or both. Replies arrive as message.received and thread into the same conversation.
Everything you need to send and receive

quick nudge, rent's due today 🏠 you haven't marked it as paid
omg thank u i literally forgot again
Payment sentYou sent $1,200.00 USD to Roger SmithFromBank of America •••• 1234DateJul 30, 2025Amount$1,200.00 USDConfirmation number9XK6482WL
SMS & MMS
Zernio's Messaging API supports sending and receiving both SMS and MMS (include mediaUrls).

Zernio Brand
Standard 10DLC
Status
Brand
Numbers
Submitted
Brand registered
Carrier status: VERIFIED
Campaign approved
Carrier status: MNO_PROVISIONED
Attach a number
A registration only covers the numbers you attach to it.
Carrier registration
US numbers must be registered (10DLC or toll-free) before sending SMS. You can register them via our API.
Reuse approvals
If you already have an approved 10DLC campaign, reuse it for new numbers to skip re-approval and paying again.
White-label form
Need your customer to complete the registration? Send them a secure link. They can fill it out without a Zernio login.
Opt-outs
Recipients who reply STOP are blocked by the carrier. Sync the list with GET /v1/sms/opt-outs.
Number lookup
Check a carrier and line type (mobile, landline, VoIP) before sending SMS to avoid landlines and validate numbers.
Brand as a sender
Sending internationally? Use a branded sender ID instead of a phone number.
Appeals
Campaign rejected? Fix the flagged details and appeal without starting over.
Built for the texts that have to land
Order & shipping alerts
Confirm purchases, share tracking links, and include STOP so opt-outs stay compliant.

Your order #4821 has been shipped 📦
Sat 7:32 PMTrack: acme.co/t/4821. Reply STOP to opt out
Delivered
Sat 12:21 PMRate your delivery: acme.co/r/4821
2FA & OTP
Send one-time codes from a registered number so they actually deliver.

Stripe
Your code is 729 304. It expires in 10 minutes. If you did…
Two-way support
Customers reply by text, conversations land in the same inbox as WhatsApp and the rest.

hey, my package says delivered but I don't have it
Sorry about that, checking now.
any update?
Found it. Re-delivery tomorrow 10–12. Want a call instead?
Appointment reminders
Confirm, reschedule, or cancel over SMS, using your trusted business number.

Reminder: dental cleaning tomorrow at 3:00 PM
Reply YES to confirm or STOP to opt out
Yes
Confirmed for Thu 3:00 PM.
REST, 8 SDKs, or let an agent do it
Call it from Node, Python, Go, Ruby, Java, PHP, .NET, or Rust, or the raw REST API and CLI.
Node
import Zernio from '@zernio/node'; const zernio = new Zernio(); // reads ZERNIO_API_KEY const { data } = await zernio.sms.sendSms({ from: '+14155550142', to: '+13105559999', text: 'Your order has shipped!', }); console.log(data.status); // sent ✓ 200 · sent
Your agent already knows how to text
The full SMS surface is on our MCP server. Ask it to send a message, it handles the number and registration.
MCP server
›
Claude Code v2.1.19
Opus 4.5 · Claude Max
~/software
›
✓ found SMS-enabled number +1 (415) 555-0142
✓ registration approved · reused existing 10DLC campaign
✓ message queued · id msg_8f2a
Transparent SMS pricing
Usage is billed per segment, plus US carrier registration fees when you register.
Starting at
$0.008
Per outbound message
US registration
$9 brand · from $3/mo campaign
Frequently Asked Questions
Still have questions?
Send your first SMS today
Get an SMS-capable number, register once (US), and send. Replies land in the same inbox as everything else
- SMS + MMS
- 10DLC handled
- Replies in one Inbox