How we built RockBank’s multichannel payment reminder flow with Cursor and Sinch

For many teams, implementing a new communications channel like SMS, RCS, verification, or email into a build usually takes a quarter to ship. And it isn’t due to coding time, but because of the time it takes to read API docs, set up the credentials, register the webhooks, and go through lengthy compliance review.

We wanted to see what that timeline looks like when Cursor’s AI agent handles the integration work, building directly against Sinch’s APIs instead of a developer team working through them by hand, something we’re highlighting as Sinch plans to be part of the SpaceXAI Partner Network, launching later this fall.

For RockBank, a demo bank, we built a customer communications flow in Cursor with the Sinch plugin in an afternoon, testing against a real account as we went:

• An SMS payment reminder
• The same flow upgraded to RCS, with a working “Pay now” button
• Identity verification before any payment goes through
• AI triage on inbound support replies
• An email confirmation once the payment lands
• A voice call reminder

That live-account testing matters for financial services messaging. The flows above were checked against real message delivery and webhook behavior, rather than a sandbox, as this is the same bar they’d need to clear before compliance sign-off for a regulated industry.

Here’s a quick overview of how this build comes to life in a real world setting, along with what it means for the business behind it:

Our developer advocate documented the entire build, prompt by prompt, including where it went wrong and the gotchas worth knowing before you start. Read the full build walkthrough.

If you’re ready to try it yourself, install the Sinch plugin for Cursor and start with your own account.

Cursor has changed what developers can build, and how fast they can build it. As a launch partner in the SpaceXAI Partner Network, Sinch brings enterprise-grade communications infrastructure into the Cursor workflow, helping developers connect AI-built applications with customers reliably and at scale.

Together, Cursor and Sinch close the gap between working code and production-ready customer communications within the developer workflow. The result is an application that developers can ship, backed by a communications layer built to support the reliability, security, compliance and scale that production demands.

Install the Sinch plugin for Cursor and see what it builds with your own account. Want the backstory on the plugin itself? Read the Sinch plugin for Cursor launch announcement.

Author: The Sinch team