OAuth2
also: OAuth 2.0, OAuth2.0
OAuth2 is an open authorization protocol that allows users to grant third-party applications access to their resources without sharing passwords. It uses tokens instead of credentials for secure, delegated access.
OAuth2 is a standardized framework for authorization (not authentication) that enables secure delegated access. Rather than giving an application your password, OAuth2 lets you authenticate with a trusted provider (like Google or GitHub) and receive a time-limited token that grants specific permissions to your data.
In Linux contexts, OAuth2 is commonly used for API authentication, CI/CD pipelines, and cloud service integrations. For example, you might authorize a GitHub Actions workflow to access your repository without embedding your password in configuration files.
The protocol involves three parties: a resource owner (you), a resource server (the service holding your data), and a client (the application requesting access). The flow typically redirects to a login page, grants permissions, and returns a Bearer token for subsequent API calls: Authorization: Bearer YOUR_TOKEN_HERE