Transloadit does not offer an explicit means to keep track of who of your users submitted a specific file. However, we offer something much more flexible than that.

We allow you to add custom data to your Assemblies in the form of fields. For example, you can add a hidden field user_id to your form, populate its value attribute accordingly, and then set Uppy Transloadit Form's⁠ fields parameter to include the field.

This field will then become available in your Assembly as ${fields.user_id} and will also be appended to a fields array in the JSON response for you to save in your database.

You can read more about custom fields in Assemblies here.