Add SMS to your app in
minutes, not months.
Two files. Your AI coding tool. A working SMS feature.
How it works
Shorter than your last standup.
Pick your use case
A full library of compliant messages.
Hand it to your AI
Drop two files in. Your AI handles the rest.
Go live when you're ready
Build in a fully functional sandbox. Free.
Free to build and test. $49 to register, then $19/mo.
Explore use cases
Every message is pre-written, tailored to your use case, and ready for carriers.
Appointments
Confirmations, reminders, reschedules, cancellations, no-show follow-ups
Verification codes
Login OTPs, signup codes, password resets, MFA, new device alerts
Order updates
Shipping confirmations, delivery alerts, return status, refund notices
Customer support
Ticket updates, resolution notices, satisfaction follow-ups
Marketing
Promos, re-engagement, product launches, seasonal campaigns
Team alerts
Shift reminders, system alerts, escalation pings, on-call notifications
Community
Event reminders, group updates, membership alerts, RSVP confirmations
Waitlist
Spot available, queue position, reservation holds, invite codes
Simple pricing
Free to build. Pay when you go live.
Free
Build and test your SMS integration. No credit card, no time limit.
- Test API key and sandbox phone number
- Pre-written messages for your use case
- Setup instructions your AI coding tool can follow
- Works with Claude Code, Cursor, Windsurf, GitHub Copilot, Cline, and others
Go live
Full refund if not approved.
- Carrier registration handled for you
- No credit card to start building
- 500 messages included per month
- Dedicated phone number
- Every message scanned — issues caught and fixed before they reach carriers
- Need more messages? $8 per 500. Scales with usage.
Volume pricing available above 5,000 messages
Why RelayKit?
Your messages keep delivering. We make sure of it.
Other platforms send your messages and hope for the best. RelayKit checks every message before it goes out, watches for problems after delivery, and alerts you when something needs attention — before carriers do.
Every message checked before sending
We scan outbound messages against carrier rules. If something looks risky, we flag it before it reaches your users.
Opt-outs handled for you
When someone replies STOP, their number is blocked immediately — no code on your end. If you accidentally try to text them again, we block it and tell you why.
We notice when things drift
As your app evolves, the messages it sends can gradually shift from what was originally approved. We watch for this and tell you what to fix.
You’ll know when something needs attention
If we block a message or detect a problem, you hear about it — dashboard alerts, email, or text. No issues sitting quietly on a dashboard waiting for you to notice.
Every compliance feature is included for every customer. No paid tiers. No add-ons.
You shouldn't need a telecom degree to text your users.
Adding SMS should take an afternoon. Instead, you're stuck navigating carrier registration, building compliance pages, and hoping your submission doesn't get rejected. RelayKit handles all of it.
Registration
Carriers require it before you can send a single text. Most people get rejected the first time.
DIY
Learn 10DLC. Fill out carrier forms. Wait weeks.
Others
Same forms. You’re on your own.
RelayKit
Handled, or your money back.
Message content
Carriers review exactly what you plan to send. Write the wrong thing and your submission is denied.
DIY
Write messages. Hope carriers approve them.
Others
No guidance. No templates.
RelayKit
Pre-written but flexible options, tested for your use case.
Opt-out handling
Reply STOP must actually stop. Get it wrong and you’re liable.
DIY
Build STOP/HELP yourself. Get TCPA wrong, you’re liable.
Others
Some offer it. Most don’t.
RelayKit
Handled automatically. No code needed.
No contracts. Cancel anytime. Your code stays yours.