Act vs Clerk

act is an open-source command-line tool that runs GitHub Actions workflows locally using Docker containers. It reads workflow files from .github/workflows/ and executes them with environment variables and filesystem configurations matching GitHub's hosted runners. The tool enables fast local feedback on workflow changes without requiring commits and pushes to a remote repository.

Clerk is a complete user authentication and management platform that provides secure sign-in, multi-factor authentication, and user profile management out of the box. It simplifies the complex process of building authentication systems with pre-built UI components and flexible APIs.