Aider

The change is small but everywhere: rename one function and the ripple touches eleven files. Instead of hunting them down, you open a terminal in your project, tell Aider what you want in plain English, and watch the edits land in your actual files, then get committed to git with a sensible message you didn't have to write.

Aider is open-source AI pair programming in your terminal. Point it at a brand-new project or a codebase you've lived in for years; it builds a map of the whole repository, so its edits stay coherent even in large projects where a change in one file implies changes in three others. It connects to Claude, OpenAI's models, DeepSeek, and almost any other LLM — including models running on your own machine — and works across more than a hundred programming languages: Python, JavaScript, Rust, Go, PHP, and the long tail.

The small details are where it wins you over. Paste in a screenshot of a broken layout or the URL of the docs you're following, and that context rides along. Dictate a request out loud when your hands are busy. Let it lint and test the code it just wrote and fix what fails. And because every change arrives as a git commit, undoing an experiment is ordinary git, not archaeology.

Honesty, though: this is a developer's tool. It assumes a terminal, a git repository, and access to a model. If none of those words are yours yet, other tools in this catalog will meet you closer to home. If all three are, installation is one line: python -m pip install aider-install.

One number worth sitting with, from the project's own release stats: in a recent release, Aider wrote 88 percent of its own new code.

Try this for a first session. Pick a small annoyance in a repo you know well, ask for exactly that fix, and read the diff before you accept it. That first diff will tell you whether Aider becomes part of your week.