SMS API for Developers

Send or receive SMS and MMS globally with Zernio Messaging API

+1 (415) 555-0142

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

Global SMS coverage

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
How It Works

From number to first SMS in three steps.

1

United 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

Active

SMS

Off

Texts United States numbers only (no international SMS)

Picture & media messages (MMS) supported

Turn on SMS

Calls & Voicemail

On

No 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.

3

Messages

All platformsAll profilesAll accounts

Conversations

3

34647509795 · via +1 707 605 9837

All works!

2h
A

Amirah Temitope via +1 707 605 9837

Hey! 👋 Zernio is a social media scheduling and inbox API that...

21h

Send

Send a message with text, mediaUrls, or both. Replies arrive as message.received and thread into the same conversation.

Features

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

Approved

Submitted

Brand registered

Carrier status: VERIFIED

Campaign approved

Carrier status: MNO_PROVISIONED

4

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.

Use cases

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 📦

Track: acme.co/t/4821. Reply STOP to opt out

Delivered

Rate 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.

Ways to integrate

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.

Read the docs

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

Pricing

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