Hi @Nicholas Roeder ,
You can upload files to OneDrive, and the contents of the request body should be the binary stream of the file to be uploaded.
With following example, I am able to upload a image file.
PUT /me/drive/root:/FolderA/FileB.png:/content
Content-Type: image/png
The contents of the file goes here.
Here is the result of my test,
Reference: driveitem-put-content.
Hope this helps.
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