Aider is an open-source AI pair-programming tool that works directly in the terminal and edits code inside an existing Git repository. Developers can connect supported language models, describe changes conversationally, and let Aider inspect files, modify code, create commits, and work across larger codebases. It is designed to fit into a normal command-line development workflow rather than requiring a separate IDE, making it useful for feature development, refactoring, debugging, tests, and documentation.

Aider supports many model providers and includes repository-aware context handling so the assistant can reason about project structure without loading every file at once. Git integration makes changes easier to inspect and revert, while voice, image, linting, testing, and automation features extend the workflow beyond simple chat-based code generation. Aider is a strong choice for developers who prefer model flexibility and terminal-based coding while retaining direct control over their repository and version history.