OAuth 2.0 Client Credentials Grant

tools.ietf.org/html/rfc6749#section-4.4

The Client Credentials grant type is used by clients to obtain an access token without a separate authorization step. The client credentials themselves act as the authorization to access the resources.

This is typically used by clients to access resources about themselves rather than to access a user's resources.

More resources

• Client Credentials (oauth.com)
• Application Access (aaronparecki.com)
• Secure a Node API with OAuth 2.0 Client Credentials (developer.okta.com)