Authentication is a fundamental aspect of software development, especially when dealing with open-source and proprietary software, as it ensures secure access to code repositories. Git supports two main authentication methods: HTTP(S), which uses usernames and passwords or personal access tokens (PATs), and SSH, which uses public keys. While SSH is more secure, it can be challenging to set up, whereas PATs are easier but less secure. To streamline the authentication process, Git relies on credential managers that securely store authentication information. The Git Credential Manager (GCM) Core, a new open-source tool available for Windows and macOS, aims to unify the Git authentication experience across platforms by supporting GitHub, Bitbucket, and Azure Repos, with plans to extend to Linux and other hosting services. GCM Core simplifies the authentication flow with interactive sessions and supports various two-factor authentication mechanisms while securely storing credentials. It was developed in response to the fragmented landscape of previous credential managers and the need for a cross-platform solution, leveraging .NET Core and .NET Standard to enhance compatibility across different environments. The tool remains in beta, and developers are encouraged to contribute to its evolution as it seeks to provide a seamless authentication experience for all users.