Client Authentication in PSPDFKit Instant
To use PSPDFKit Instant for Flutter, you have to authenticate your client with your running Document Engine instance. This can be done by generating a JSON Web Token (JWT) and sending it to the client. In most cases, your backend application will generate and send the JWT to the client. The client can then use the JWT to authenticate itself with Document Engine, which will return only the data that the user is authorized to view.
A JWT typically grants access to a specific document and Instant layer combination. If you’re having difficulty generating valid JWTs, you can use the [Document Engine dashboard][pspdfkit server dashboard] to validate them.