You should be able to set the MIME type: https://github.com/lastmjs/zwitterion#headers-file https://github.com/lastmjs/zwitterion#headers-file In the case abov

You should be able to set the MIME type: https://github.com/lastmjs/zwitterion#headers-file https://github.com/lastmjs/zwitterion#headers-file In the case above, you would need to say type="module", because you are importing a module even if it is tsx. But, you should be able to set the MIME type for .tsx files with a custom header file