I wish I could export or backup Coda better than current “Export Option”
(current export option exports plain txt files, without formatting and without images)
I have seen that Notion.so export feature is better:
it exports as html files (keeps formatting and images)
This is true, but using the Gmail Pack, you can export sections with full HTML representations and embedded images. It’s a bit tedious setting it up, but a fairly useful approach. Bear in mind, SMTP messages carry both plain text and HTML payloads of the Section content.
You can now use the REST API to export to HTML or Markdown. This is however page at a time, so you would have to couple this with listing/enumerating the pages/subpages of a document and export each one Coda API (v1) Reference Documentation