OptionalcaptionAlt text / description for the file event.
The bytes to upload.
OptionalfilenameSuggested filename.
OptionalmetadataRail-specific or shell-specific extra metadata.
OptionalmimeMIME type; inferred from data when omitted.
OptionalnoRequest the server not re-encode the file (NIP-96 no_transform).
OptionalrailStorage rail; omit to let the shell pick a configured default.
A napplet's upload request.
datacrosses the postMessage boundary by structured clone — shells never require base64 encoding.