TextLink LLC · 2026 – active

SMS gateway sold as a SaaS product

The story

A tool that needed a developer is now a product 3,800 phone owners run themselves.

A spare Android phone sends SMS through its own SIM at carrier cost. We extended an open-source gateway into the product TextLink sells: dashboard, integrations, billing and public site.

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Worth noting

· 19.4M messages sent, 99.2% delivered
· A tenth of a cent a message, 95% below carrier rates
· No carrier registration or paperwork for the customer

The problem

Sending SMS to US numbers at scale means 10DLC, the US carriers' registration scheme: brand vetting, campaign approval, weeks of paperwork, and prices from around $0.0075 a message. For smaller operators, agencies and fleets that is expensive and slow enough to push them back to notifying clients by hand. Android gateways that send through a phone's SIM exist, but each needs a technical person to set up and maintain. TextLink wanted that infrastructure mass-market, with interfaces a non-developer can use.

Outcome

It sells as a self-serve product on AppSumo across five lifetime tiers, from a single operator to unlimited SIMs, with unlimited messaging inside every tier. As of writing, around 19.4M messages have gone out across 3,800+ connected phones, at an average send of about 2.3s.

What we built

We extended the open-source gateway core so one installation serves many customers, and built the product around it. Non-developers work from a dashboard: one inbox for every conversation, bulk campaigns with delivery tracking, SIM warmup that builds a new number's reputation, and analytics down to reply rate and opt-outs. Agencies attach a SIM to each GoHighLevel location and send and reply from the CRM they already use. Developers get a public API. Pairing a phone is a QR scan. We also designed and built the site that sells it.

What it covers

Accounts, teams and locations, chat inbox, bulk campaigns, SIM warmup, GoHighLevel integration, public API and verification, device pairing and telemetry, billing, analytics, presentation site.

How we approached it

We started from a proven open-source gateway so the effort went where the product value was. First we hardened and extended the core so it could carry many customers. Then came the commercial surface: a dashboard a non-developer can operate, billing, and above all the GoHighLevel integration, because that is where the buyers already work. Sending through real consumer SIMs means the sender's reputation is part of the product, which is why SIM warmup and delivery tracking exist. The developer API exists so other software can build on it.