Nested folders failing to upload in widget

kannydennedy Member Posts: 3
edited July 2023 in Developer APIs

I've set up signed uploads with my upload widget. When I drag a single folder into the uploader, everything works fine. When I drag a nested folder into the uploader, it fails with a lot of 'invalid signature' errors. I swear this was working before, I don't know what changed. I think before (a few days ago?) it was flattening the folders in the Cloudinary console, now the folders are getting added in the console as well.

On the backend I just have

const signature = cloudinary.utils.api_sign_request(






  • kannydennedy
    kannydennedy Member Posts: 3

    My frontend




    api_key: XXXXX,

    cloudName: XXXXX,

    upload_preset: XXXXX,

    sources: ["local", "dropbox"],

    uploadSignature: generateSignatureWithSocket,

    buttonCaption: "Upload assets",

    clientAllowedFormats: ["jpg", "jpeg", "png", "mp3", "wav"],

    styles: uploaderStyles,

    button_class: "uploader-button",

    max_files: 20000,

    // Downscale the image to 800px width / 500 height

    maxImageWidth: 800,

    maxImageHeight: 500,

    folder: XXXXX, // I've tried with and without this

    use_filename: true,


    (error, result) => {}


  • kannydennedy
    kannydennedy Member Posts: 3

    It seems that when nested or multiple folders are uploaded, the params_to_sign becomes an array of params to sign, which is probably not helping.

  • epasos
    epasos Member, Cloudinary Staff Posts: 23

    Hi @kannydennedy ,

    The upload widget has the `pre-Batch` validation feature where you can analyze and get the folder structure for the source file (see And using the information, you can update the `folder` parameter to where your files will be uploaded in your Media Library account through the `prepareUploadParams` event (see In the same event, the signature can be calculated as well.