How Cas Link works
An overview before you try the demo
Cas Link is the bank-linking screen embedded right inside your app. Your customer never has to leave it and keeps seeing your interface and branding. Cas handles the whole bank login, OTP and any errors along the way.
The linking flow starts when your customer wants to connect their financial account to your app. Here are the steps:
Click the “Link bank account” button in the diagram to watch the flow. Hover any block for an explanation.
Your appYour serverCas
- Your customer taps “Link bank account” right inside your app.
- Call
POST /grant/tokento create a grantToken, then return it to your app front end. - Use the grantToken to open Cas Link for your customer. On success Cas returns a temporary publicToken.
- Call
POST /grant/exchangeto exchange the publicToken for an accessToken and its grantId. - Store the accessToken wherever you consider safe and use it to call the APIs.