When your application requests public data, the request doesn't need to be authorized, but does need to be accompanied by an identifier, such as an API key.
Your application needs to identify itself every time it sends a request to the Google Knowledge Graph Search API, by including an API key with each request.
Acquiring and using an API key
To acquire an API key:
- Open the Credentials page in the API Console.
This API supports two types of credentials.
Create whichever credentials are appropriate for your project:
OAuth 2.0: Whenever your application requests private user data, it must send an OAuth 2.0 token along with the request. Your application first sends a client ID and, possibly, a client secret to obtain a token. You can generate OAuth 2.0 credentials for web applications, service accounts, or installed applications.
Note: Since this API doesn't have any methods that require OAuth 2.0 authorization, you might only need to obtain API keys, which are described below. However, if your application calls other APIs that require user authorization, then you still need OAuth 2.0 credentials.
For more information, see the OAuth 2.0 documentation.
API keys: A request that does not provide an OAuth 2.0 token must send an API key. The key identifies your project and provides API access, quota, and reports.
The API supports several types of restrictions on API keys. If the API key that you need doesn't already exist, then create an API key in the Console by clicking Create credentials > API key. You can restrict the key before using it in production by clicking Restrict key and selecting one of the Restrictions.
To keep your API keys secure, follow the best practices for securely using API keys.
After you have an API key, your application can append the query parameter
key=yourAPIKey to all request URLs.
The API key is safe for embedding in URLs; it doesn't need any encoding.