Aider can be a chat interface and it's great for that but you can also use it from your editor by telling it to watch your files.[1]

So you'd write a function name and then tell it to flesh it out.

  function factorial(n) // Implement this. AI!

Becomes:

  function factorial(n) {
    if (n === 0 || n === 1) {
      return 1;
    } else {
      return n \* factorial(n - 1);
    }
  }

Last I looked Aider's maintainer has had to focus on other things recently, but aider-ce is a fantastic fork.

I'm really curious to try Mistral's vibe, but even though I'm a big fanboi I don't want to be tied to just one model. Aider lets tier your models such that your big, expensive model can do all the thinking and then stuff like code reviews can run through a smaller model. It's a pretty capable tool

Edit: Fix formatting

[1] https://aider.chat/docs/usage/watch.html