curl --request GET \
  --url https://api.hubapi.com/content/api/v2/templates/{template_id}

{
  "category_id": 1,
  "cdn_minified_url": "",
  "cdn_url": "http://cdn2.hubspot.net/hub/62515/hub_generated/template_resource/1382477851647/custom/page/examples/simple-template.html",
  "deleted_at": 0,
  "folder": "examples",
  "generated_from_layout_id": null,
  "id": 359393980,
  "is_available_for_new_content": true,
  "is_from_layout": false,
  "is_read_only": false,
  "label": "Simple-template",
  "linked_style_id": "",
  "path": "custom/page/examples/simple-template.html",
  "portal_id": 62515,
  "source": "The template source goes here",
  "template_type": "4",
  "thumbnail_path": null,
  "thumbnail_width": 154,
  "type": "",
  "updated": 1382477851000,
  "updated_by": ""
}