为什么Google Knowledge Graph API无法返回我所知道的拥有Google Knowledge Panel的业务？

Question

I am trying to programatically find out whether a given company has a google knowledge panel. for instance, when i search google for the company "Aeronaut Brewing Company", I get a sidebar that displays relevant information about the company. This is called the knowledge panel. Google's knowledge graph api is supposed to return this information, and for aeronaut it does:

https://kgsearch.googleapis.com/v1/entities:search?query=Aeronaut+Brewing+Company&key=YOUR_API_KEY&limit=10&indent=True

However, I've noticed that plenty of companies who have a knowledge panel do not show up in google knowledge graph api. for instance:

The Affton Chamber of Commerce has a sidebar on google ( link ), but a google knowledge graph search comes back as only the following JSON (basically it's empty):

https://kgsearch.googleapis.com/v1/entities:search?query=affton+chamber+of+commerce&key=YOUR_API_KEY&limit=10&indent=True

@context    
@vocab  "http://schema.org/"
goog    "http://schema.googleapis.com/"
EntitySearchResult  "goog:EntitySearchResult"
detailedDescription "goog:detailedDescription"
kg  "http://g.co/kg"
@type   "ItemList"
itemListElement []

What's going on? Shouldn't google knowledge graph API contain everything that has a knowledge panel on google??

Answer 1

The MID (machine-generated identifier, also known as Google Knowledge Graph ID) of the Affton Chamber of Commerce is /g/1hg4ww6pq ( SERP link ). Unlike the entities that start with /m/ that originated from Freebase, /g/ entities are internal to Google and don't tend to be exposed through the Knowledge Graph API.