Aider is a command-line tool that pairs you with a language model to edit code in an existing git repository. It maps the codebase and commits each change it makes.
aider.chatAider
AI pair programming in your terminal
What it does
Aider edits the code of a git repository with a language model from the terminal: you describe the change, aider writes it into the files and commits it. It works with cloud models through an API key or with local models.
Who it suits
Developers who already work in a terminal and have access to a model, through a provider's API or a local runner such as Ollama.
Price
Aider itself is free and open source. The model it talks to is billed by its provider, or costs nothing when it runs locally.
Read on github.com on 27 October 2026. Prices change: the official page is the reference.