Aider

Aider is an open-source AI pair programming tool that runs entirely in your terminal. You add files to the session, describe what you want changed, and it makes coordinated edits across multiple files, then automatically commits the changes to git with a descriptive message. It works with OpenAI, Anthropic Claude, and local models via Ollama — you bring your own API keys, so there's no separate subscription beyond model costs.

Best for experienced developers and command-line natives who want AI assistance without adopting a new editor. If you're doing open-source work, refactoring large codebases, or writing code on remote servers via SSH, Aider fits naturally into your workflow. The git integration is particularly good — every AI change is a clean, attributed commit you can review, squash, or revert.

Where it has friction: the terminal-only workflow feels archaic if you're used to visual editors. Context management requires explicitly adding files to the session. Token costs add up since it sends full file context each turn. But for developers who value tool ownership and workflow control, Aider is one of the best AI coding tools available — and it's completely free to run.