passport-facebook is a Passport strategy for authenticating users with their Facebook credentials using the OAuth 2.0 protocol, enabling Node.js applications to let visitors log in with their Facebook account easily. It manages the redirection to Facebook’s login page, the authorization code exchange, and the retrieval of basic profile information, reducing the boilerplate developers would otherwise write to integrate with Facebook’s API manually. When used with Express and Passport, the strategy triggers redirects and callback handling automatically based on configured routes, so developers can focus on application logic like user onboarding and account linkage. ...