Work across many files in a real project
Goal. Move from one file to a whole project — and let Aider reason across files it isn't directly editing.
Move the column-parsing logic into a helpers.py module and update analysis.py to import it.
Start Aider with more than one file — e.g. aider --model sonnet analysis.py helpers.py — and ask for a change that spans both.
- 1Launch Aider with several files at once. It edits all of them in one session, committing each coherent change to Git so a multi-file refactor stays reviewable.
- 2Aider maps your codebase, so the model can reason about how files relate even in a larger project — it understands callers and definitions without you pasting every file in.
- 3Lean on this for real tasks: splitting a script into modules, threading a change through several files, or building a small analysis pipeline — with Git tracking every step so you can always roll back.
You'll see. A change applied consistently across multiple files, with Aider drawing on its map of the whole project — and each step landing as a Git commit.
Cost. Larger context (more files, the codebase map) means more tokens per request — another reason to pick an economical model from the leaderboard for routine work.
Takeaway. Aider scales from a single script to a real codebase: it maps how your files relate and edits across them while keeping every change in Git.