Updated November 15, 2022. Unshared projects can no longer be opened on TurboWarp, forkphorus, and other third-party sites due to changes to the Scratch API.
This page answers most of the questions people have. Please read it in full before discussing these changes with other people to avoid misinformation.
You've had nearly 6 months notice to update your workflows, so hopefully you've done so by now.
ANY website other than scratch.mit.edu that asks for your Scratch password is a SCAM, even if it supposedly lets you share your unshared projects with other users. You WILL have your account stolen and projects deleted. There are NO EXCEPTIONS to this rule.
We want to be clear: These changes were made by the Scratch Team, not the TurboWarp maintainers. TurboWarp is not affiliated with the Scratch Team in any way.
Downloading a project from the Scratch API now requires a "project token" that, for unshared projects, can only be accessed by the owner of the project. Even if you're signed in to your Scratch account in the same browser, TurboWarp can't access it. These tokens are temporary and expire after a few minutes, so the owner can't just provide the token to keep it visible forever.
Unshared projects were always something that just happened to work and weren't the intended main use of TurboWarp. Things like the compiler and addons have always been the focus and will continue to work for shared projects, projects loaded from files, and the desktop app.
For testing your own projects: You can use the File > Save to your computer and File > Load from your computer menus in the Scratch editor to load your unshared Scratch projects in TurboWarp or upload projects made in TurboWarp to Scratch. Alternatively, many people have had success working on their projects primarily in TurboWarp either using the website or desktop app and uploading their projects to Scratch when they're complete (please make routine backups when doing this).
For collaborations: The best way to share a project with other people is to share it on the Scratch website. The Scratch community is really nice. This is what Scratch wants you to do. Perhaps you can share certain projects on a second account. It's okay to share unfinished projects. Scratch is 15 years old while TurboWarp is two years old. Collaborations happened just fine during the 13 years without TurboWarp and will continue just fine.
For embedding in other websites: To embed unshared projects in other websites, either Share the project on Scratch or download the project to your computer with the File > Save to your computer menu in the Scratch editor, and use the TurboWarp Packager to convert this project to a standalone file that can be embedded.
There are ways to generate links that include a temporary project token that will work for a few minutes using tools that Scratch policies do not let us discuss. For more, see ?token=.
This is a good thing
Securing unshared projects is a decade overdue.
Don't pretend that no one has had their project stolen because they didn't know unshared projects aren't actually private even though the Scratch website says "only you can see it". Many unshared projects include pictures and videos of children, their friends, their family, and other personal information under the assumption that unshared projects are actually private.
In most other large websites, "unshared" or "private" things actually being effectively public would be considered a critical security bug and would usually be eligible for a very large bug bounty. (example)
We've always had the stance that if people want unshared projects to actually be private, they should talk to the Scratch Team, and perhaps enough people did that for the Scratch Team to listen.