wtf is cli?

The sequelize CLI is a command-line tool that helps developers manage database changes in Node.js applications that use Sequelize, a popular library for working with databases. Instead of manually writing SQL commands or clicking through a database interface to create tables, update columns, or change schemas, developers run short text commands in their terminal to handle these tasks automatically. The tool focuses on "migrations," which are essentially saved, version-controlled steps for changing a database's structure over time. For example, when adding a new feature that requires a new table, a developer creates a migration file that describes the change. Running sequelize db:migrate applies all pending migrations to the database, while db:migrate:undo rolls back the last one if something went wrong. The CLI can also scaffold a new project structure and generate starter files for models (the code that represents database tables) and their corresponding migrations. This tool would be used by developers or teams building Node.js applications who want a reliable, repeatable way to evolve their database schema alongside their code. A concrete example: a startup adding a "user profiles" feature would use the CLI to generate a model and migration, define the new columns (like "bio" or "avatar_url"), and apply the change to both their local development database and production with the same commands. This avoids the risk of manually applying different changes to different environments. The tool offers flexible configuration. Developers can store database credentials in a JSON file, pass a connection string directly via a flag, or use environment variables, which is useful for keeping production credentials secure. It supports both JavaScript and CoffeeScript for writing migrations. The README doesn't go into detail on advanced use cases, but it covers the essentials: setup, available commands, configuration options, and the expected format for migration files.