Gandalf is a suite of developer tools for securely requesting user data from online services that lack a first-party API starting from Netflix, YouTube, Amazon & Playstation.
Gandalf allows end-users to share a wide range of data; the shows they've watched, the games they've played, their shopping history, etc.
There's nothing like it out there. Without Gandalf, Heimdall won't be possible. There's no way to securely request end-user data across platforms like Amazon, Instacart etc.