unsupported_media_type

What to do: File uploads are not supported yet; send text fields only.

multipart/form-data is accepted for text parts. A file part returns this error.

Shape

{ "error": { "code": "unsupported_media_type", "message": "…", "hint": "File uploads are not supported yet; send text fields only.", "docs": "https://postbag.dev/docs/errors/unsupported_media_type/" } }

All codes are listed on the error reference. Conventions for the envelope, hints and next[] are in the API overview.