Facebook API "from" field missing in page feed - facebook

Question

I am developing a program that needs to read a facebook page's posts. I have obtained a permanent page token which I can run through the "debug_token" endpoint in the API explorer and can see I have a page token with no expiry with the "manage_pages" and all the relevant pages permissions:
"data": {
"app_id": "xxxxxxxxxxxxxxxx",
"type": "PAGE",
"application": "Second",
"data_access_expires_at": 1583432075,
"expires_at": 0,
"is_valid": true,
"issued_at": 1575649224,
"profile_id": "yyyyyyyyyyyyyyy",
"scopes": [
"user_events",
"email",
"read_insights",
"manage_pages",
"pages_manage_cta",
"pages_manage_instant_articles",
"pages_show_list",
"publish_pages",
"read_page_mailboxes",
"ads_management",
"ads_read",
"business_management",
"pages_messaging",
"pages_messaging_phone_number",
"pages_messaging_subscriptions",
"publish_to_groups",
"groups_access_member_info",
"public_profile"
],
...
Using this same token I query the /{page_id}/feed and I get a response with no "from" field:
"data": [
{
"id": "xxxxxxxxxxxxxxx_yyyyyyyyyyyyyyy",
"created_time": "2019-12-05T20:24:24+0000",
"message": "Bla bla bla"
},
{
"id": "xxxxxxxxxxxxxxx_yyyyyyyyyyyyyyy",
"created_time": "2019-11-20T18:17:54+0000",
"message": "Bla bla bla"
}
...
Even if I explicitly request "from" in the fields I don't get it back and the API explorer shows the field greyed out on the left hand side with a tooltip saying: "Fields is empty or disallowed by the access token".
Obviously the "from" field is not empty, it is disallowed. I understand that this is protected information in most cases but the "feed" endpoint documentation says
Publicly Identifiable Information - User information will not be in included in responses unless you make the request with a Page access token.
https://developers.facebook.com/docs/graph-api/reference/v5.0/page/feed
So, this request is being done with a page access token, for the page that is the recipient of these posts. I am doing these posts myself with another vanilla account by the way, with no tweaking of permissions or privacy options. It seems legitimate to want the source of the post to know who you are talking to, right?
I've searched and tried other responses but answers are somewhat old and the rules in the facebook API do change often, so this is all fresh (as of Dec 2019).
The last relevant bit I want to add is that this page and app are not associated with a business manager account. From what I read, this should not be necessary for what I am trying to do.
Thank you.
Debug infor on token
Missing from field from feed

Answer 1

Ok, I figured this out myself. Hopefully the answer might help someone else in a similar situation.
The issue was that my app has a "development" status, and rightly so. According to the following security document from FB:
App users can only access the data of users who have a role on the app.
https://developers.facebook.com/docs/apps/security/
This extra layer of protection was keeping my app from even seeing who was directly posting on its associated page.
I gave the posting account a "tester" role on the app and now the response has the from field as expected:
"data": [
{
"id": "xxxxxxxxxxxxxxx_yyyyyyyyyyyyyyy",
"created_time": "2019-12-05T20:24:24+0000",
"from": {
"name": "Poster Name",
"id": "zzzzzzzzzzzzzzz"
},
"message": "Bla bla bla"
},
{
"id": "xxxxxxxxxxxxxxx_yyyyyyyyyyyyyyy",
"created_time": "2019-11-20T18:17:54+0000",
"from": {
"name": "Poster Name",
"id": "zzzzzzzzzzzzzzz"
},
"message": "Bla bla bla"
}
...