AI Coding

Everyone is yelling about Cursor and Claude Code. Meanwhile, Aider quietly shipped weekly for three years, hit 30k GitHub stars, and powers more "AI engineer" demos than anything else on the planet. Yes really.

The Setup

Aider is a Python CLI by Paul Gauthier. It's git-native — every edit becomes a commit with a sensible message. It's model-agnostic — Claude, GPT, Gemini, local llama, whatever you want. And it has no telemetry, no account, no upsell.

pip install aider-install
aider-install

# point it at any model
aider --model claude-sonnet-4 \
  src/pages/book.astro src/lib/booking.ts

# inside the chat
> add zod validation to the booking form
> /commit
> /run npm run typecheck

The Money Pattern

The killer feature is the repo map. Aider builds a tree-sitter outline of every file in your repo and feeds the relevant slices into context. You get repo-wide awareness without burning a million tokens. On my Aidxn Design Astro repo it slices context smarter than half the paid tools.

> /add src/components/Hero.astro
> swap the static hero copy for content pulled from src/data/hero.json
> also add a fallback if the json is missing fields

aider: I'll edit Hero.astro and add a defensive parse.
       Committing as: "feat(hero): hydrate copy from hero.json with fallback"

Pair Aider with --watch-files and you get inline edits triggered by comments like // ai: refactor this directly in your editor. No IDE plugin, no extension, just file system magic.

The Catch

The UX is unapologetically terminal-first. If you've never used git rebase -i you will be confused. There is no slick diff viewer, no glowing accept button — just a unified diff and a prompt. The docs assume you read.

It also bills against your own API keys. That's a feature for some, a tax for others.

The Verdict

Aider is the Vim of AI coding. It will outlast every VC-backed IDE on this list. If you value tool independence and want every edit tracked in git with surgical precision, this is the one. The fact that it's free and open source while Cursor charges $25/month should be illegal.