Aider

Aider pairs you with a language model inside the terminal, on a new project or an existing codebase. Edits land in your real files, and every change is committed with a sensible message, so ordinary git tools are enough to diff, manage or undo whatever the model did.

To stay useful in larger projects, Aider builds a map of the entire repository and feeds the relevant parts back as context. More than a hundred languages are supported, among them Python, JavaScript, Rust, Ruby, Go, C++, PHP, HTML and CSS.

The workflow has several entry points beyond typing at the prompt.

• Editor mode: leave a comment in your code from any IDE and Aider picks it up and starts working.
• Linting and testing: your linters and test suite run after each change, and Aider fixes what they report.
• Images and web pages: add screenshots or reference documentation to the chat for visual context.
• Voice to code: ask for features, test cases or bug fixes by speaking rather than typing.
• Copy and paste mode: work through any model's browser chat, with context and edits shuttled back and forth for you.

Model choice is wide. It works best with the strongest coding models from Anthropic, DeepSeek and OpenAI, but connects to almost anything, local models included. Installation is a pip install of a small installer followed by one command, after which you point it at a project directory and supply an API key.