The Kelir library.Blog. Stories. Glossary.Pillars.
Everything Kelir publishes — long-form thinking on UCaaS-on-cellular, the eSIM business-line transition, the operational realities of running a phone system on actual phones. Plus the pillar pages that anchor the positioning, the glossary, customer stories, and the changelog.
Where to start.
Blog
Articles on UCaaS-on-cellular, the eSIM business-line transition, and the practical operations of running a phone system on a phone.
Manifesto + guides
Customer stories
How real-world Kelir users — solo professionals, agencies, clinics, contractors, realtors — actually run their phones.
Inline + full case studies
Glossary
Plain-language definitions for the UCaaS and cellular-eSIM terminology Kelir uses — eSIM, VoLTE, A2P 10DLC, IVR, hunt group, port-in.
16 terms
Changelog
What's new at Kelir — features shipped, integrations added, pricing changes, infrastructure milestones. RSS available.
Categorized: New / Improved / Fixed
The anchor pages.
The pages that explain what Kelir is, what a business eSIM is, how it differs from softphone delivery, how porting works, how to activate, and the security posture. Long-form, citation-engineered.
Why Kelir
The thesis: same UCaaS feature surface as RingCentral, Dialpad, 8x8, Vonage Business, Nextiva — delivered on a real cellular eSIM line.
What is a business eSIM
Definition pillar. A business eSIM delivers the full UCaaS phone system on the cellular voice network instead of as a softphone app.
Cellular eSIM vs softphone
Side-by-side comparison of cellular-eSIM delivery and softphone delivery for the same UCaaS feature surface.
Port your number
How to bring an existing US number to Kelir from any softphone UCaaS or carrier. FCC port rules, timing, and what to expect.
How it works
End-to-end activation flow. Pick a number, pay, install eSIM, the full UCaaS system is on. iPhone direct push, Android QR.
Security & compliance
Encryption, US data residency, SOC 2 roadmap, HIPAA-aware architecture, FCC + A2P 10DLC compliance, E911.