Company
The business phone system, unbundled into an API
Every vertical SaaS platform eventually needs to text, call, and take voicemail on behalf of its customers. Almost none should have to become a phone company to do it. Handset is the layer that makes that possible.
The old way vs. the handset
before
carrier contracts · 10DLC filings · number inventory · opt-out ledgers · SBCs · voicemail storage · on-call rotation
after
POST /v1/messages
Why we're building this
We've spent years inside business communications — building the phone systems that companies run on — and watched the same thing happen again and again.
A product team wants to add texting or calling for their customers. It sounds like a weekend feature. Then they meet the real telecom stack: carrier contracts, number inventory, porting, 10DLC brand and campaign registration, opt-out ledgers, session border controllers, voicemail storage, an on-call rotation for when the carrier has a bad night. Months later they've built a small, fragile phone company instead of the feature their customers asked for.
The existing APIs help, but they hand you primitives and leave the multi-tenancy, compliance, and business logic to you. If every one of your customers is a separate business with its own number and its own opt-out list, you're still building most of the hard part yourself.
Handset is the whole thing, embedded in your product. A real local number per business. Two-way SMS, inbound voice, and transcribed voicemail. Compliance handled at the platform layer. One clean API and a test mode you can build against today — everything underneath is our problem, not yours.
What we believe
The principles behind the API
Telephony is infrastructure, not a feature
Carrier interconnects, number porting, 10DLC registration, SBCs, voicemail storage — this is a decade-old, heavily regulated stack. Almost no product should rebuild it to send a text. We did the hard part once so you never have to.
Multi-tenant from the first line
Your customers are businesses, each with their own number, threads, hours, and opt-out list. Handset was designed around that from day one, not bolted on. One integration, isolated tenants underneath.
Compliance should be invisible
STOP and HELP keywords, send-time opt-out enforcement, and 10DLC brands and campaigns run at the platform layer. Your customers get a phone number that works. They never learn what a campaign registry is.
Developers ship on day one
Test mode with a simulated carrier and magic numbers lets you build the entire flow before a real phone rings. Ten minutes to your first text, in TypeScript, Python, or Go.
Who's behind it
A small team, close to the founding customers
Handset is early and deliberately small. We're onboarding a founding group of vertical SaaS platforms at design-partner rates, with hands-on onboarding and a founder on the call — because the product gets better the closer we stay to the people building on it.
If you're adding communications to your platform, we want to hear what your customers need to say, and to whom.
- Building
- The business phone API for vertical SaaS
- Runs on
- Carrier-grade voice & messaging, one clean API
- Stage
- Onboarding founding design partners
- Talk to us
- hello@handset.dev
Prefer to read code first? The docs get you to your first text in ten minutes.
Put a handset in your product.
We're onboarding a small group of vertical SaaS platforms. Tell us what your customers need to say, and to whom.