Course → Module 10: Measuring, Diagnosing, and Maintaining
Session 3 of 10

The Knowledge Graph Search API is the definitive test of entity recognition. It lets you query Google's Knowledge Graph directly and see whether your entity has an entry, what type it is assigned, and what properties Google has stored. No other tool provides this level of direct access to Google's entity database.

What the API Returns

When you query the Knowledge Graph Search API with your company name, one of two things happens. Either Google returns an entity result with structured data (you are in the Knowledge Graph), or it returns no result (you are not). The response, when present, includes:

Field What It Contains What It Tells You
name Entity name as Google stores it Whether Google uses your preferred name or a variant
@type Schema.org type (Organization, Person, etc.) How Google classifies your entity
description Short entity description What Google considers the defining description of your entity
detailedDescription Longer description, often from Wikipedia Whether Wikipedia or Wikidata is feeding your entity data
image Entity image URL What visual representation Google associates with your entity
url Canonical URL for the entity Whether Google connects your entity to your website
resultScore Relevance score (numeric) How confident Google is in the match

An empty API response is a clear signal: your entity does not exist in Google's Knowledge Graph. This is not a technical failure. It means your entity signals are insufficient for Knowledge Graph inclusion.

How to Access the API

graph TD A["Get Google API Key
(console.cloud.google.com)"] --> B["Enable Knowledge
Graph Search API"] B --> C["Make API Request
(HTTP GET)"] C --> D{"Response?"} D -->|Entity found| E["Parse entity data:
name, type, description,
score, URL"] D -->|No result| F["Entity not in
Knowledge Graph"] E --> G["Compare against
your intended
entity profile"] F --> H["Review MVES gaps"] style F fill:#2a2a28,stroke:#c47a5a,color:#ede9e3 style E fill:#2a2a28,stroke:#6b8f71,color:#ede9e3

The API endpoint is straightforward. You need a Google Cloud API key (free to create) and the Knowledge Graph Search API enabled in your Google Cloud project. The request is a simple HTTP GET:

https://kgsearch.googleapis.com/v1/entities:search?query=YOUR+COMPANY+NAME&key=YOUR_API_KEY&limit=5

The response is JSON-LD format following schema.org standards. You can also use free tools like Kalicube's Knowledge Graph Explorer or Audits.com's Knowledge Graph Search tool to query without setting up an API key.

Interpreting Results

If your entity appears in the results:

If your entity does not appear: review your MVES completion status. The most common reasons for Knowledge Graph absence are insufficient external corroboration, missing or incorrect structured data, no Wikidata entry, and low branded search volume.

Competitive Comparison

Query the API for your top three competitors as well. This reveals the entity recognition gap. If competitors appear with complete entries and high result scores while you are absent, the gap is structural. You are not competing on content quality at this point. You are competing on entity infrastructure.

Query Your Company Competitor A Competitor B
In Knowledge Graph? Fill in Fill in Fill in
Entity type Fill in Fill in Fill in
Has description? Fill in Fill in Fill in
URL linked? Fill in Fill in Fill in
Result score Fill in Fill in Fill in

Migration Note

Google is migrating the Knowledge Graph Search API to the Cloud Enterprise Knowledge Graph product. The functionality remains the same, but new users should use the Cloud Enterprise Knowledge Graph API. If you already have access to the original API, it continues to work. The migration ensures the same functionality with enterprise-scale support.

Further Reading

Assignment

Query the Knowledge Graph for your company and your top three competitors:

  1. Use the Knowledge Graph Search API (requires a Google Cloud API key) or a free tool like Kalicube's Knowledge Graph Explorer.
  2. If your company returns a result, examine every field: name, type, description, URL, and score. Is everything accurate?
  3. If no result appears, your entity is not in the Knowledge Graph. Review your MVES checklist from Module 4 and identify the gaps.
  4. Query your top three competitors. Fill in the comparison table above.
  5. Document the entity recognition gap between you and your competitors.