Talkyard List API

Then there's a different endpoint I think is better for your use case:

/-/export-site-json

which gives you all you need. It's meant for exporting one's Talkyard site and importing to another Talkyard server, or to something else.

text idallay already as rendered HTML

There's a approvedHtmlSanitized field.

I need to re-sync an entire page [...] get all of the information at once for a specific page

This endpoint currently exports the whole site, so, currently, it gives you a bit too much instead.

Maybe in the beginning, this doesn't matter much, since the Talkyard site wouldn't have that much contents, intially?

Later there can be query param like: ?newerThan=2020-05-25T00:00:00 so you wouldn't get everything.
Or ?pageId=... and then you'd get that page, the replies and authors.

The json this endpoint returns looks like:

{
  ...
  pages: [{
      "id": "8",   <—— unique id
      "pageType": 5,   <—— question / idea / problem / discussion
      "categoryId": 3,
      "createdAtMs": 1590397059126,
      "updatedAtMs": 1590397059126,
      "authorId": 100,
      "frequentPosterIds": [],
      ...
  }],

  categories: [{
      "id": 3,
      "sectionPageId": "1",
      "parentId": 1,
      "defaultSubCatId": null,
      "name": "Category Name",
      "slug": "category-name",
      "description": "Category description text.",
      "createdAtMs": 1590397023923,
      ...
  }],

  posts: [{   <—— replies, but also page titles and page bodies (orig posts)
      "id": 21,   <—— unique id
      "pageId": "8",
      "nr": 1,     <—— 0 = page title, 1 = Original Post. 2, 3, 4, ... = replies
      "parentNr": null,   <—— if replies to another post
      "createdAt": 1590397059126,
      "createdById": 100,   <—— author id
      "approvedSource": "Text text and a link: http://e2e-test--emb-exp-0397016.localhost:8080/impexp-subscr-notfs.html",
      "approvedHtmlSanitized": "<p>Text text and a link: <a href=\"http://e2e-test--emb-exp-0397016.localhost:8080/impexp-subscr-notfs.html\" rel=\"nofollow\">http://e2e-test--emb-exp-0397016.localhost:8080/impexp-subscr-notfs.html</a></p>\n",
      "approvedAt": 1590397059126,
      "approvedById": 1,
      "approvedRevNr": 1,
      ...
  }],

  members: [{
      "id": 100,
      "username": "owen_owner",
      "fullName": "Emb Cmts Exp test id 0397016",
      "emailAddress": "e2e-test--0397016@example.com",
      ...
  }],
  ..
}

To enable this endpoint go here: /-/admin/settings/features and check the Experimental checkbox, then go here: /-/admin/backup and click Download backup.

This endpoint is not yet official. It hasn't changed the past year, so it's pretty stable — but some time it'll get renamed and the JSON format will change slightly.