Aider Watch Mode — Auto-Edit on `# AI:` Comments

Quick Use

1. Already have Aider installed? Start it with aider --watch-files
2. Open any tracked file in your editor
3. Add # AI: <your instruction> and save — Aider edits and commits

Intro

Aider Watch Mode lets you trigger Aider from inside your editor without switching to a terminal. Add # AI: <instruction> (or // AI: for JS/TS) anywhere in a file and save — Aider notices, edits the file, removes the comment, and commits. Best for: developers who don't want to leave VS Code / vim / Cursor / Claude Code to invoke an AI edit. Works with: Aider 0.50+, any editor that saves files. Setup time: 1 minute.

Start watch mode

# In your repo
aider --watch-files

# Or set in .aider.conf.yml
echo "watch-files: true" >> .aider.conf.yml
aider

Aider stays running and watches all tracked files.

Trigger an edit

In any file, add an AI comment:

# main.py
def fetch_user(user_id: int):
    # AI: add caching with functools.lru_cache, max 1000 entries
    return db.users.find_one({"_id": user_id})

Save the file. Aider:

1. Detects the AI comment
2. Reads the file (and any other files relevant)
3. Edits the function and removes the AI comment
4. Auto-commits with a generated message

Result:

# main.py
from functools import lru_cache

@lru_cache(maxsize=1000)
def fetch_user(user_id: int):
    return db.users.find_one({"_id": user_id})

Multi-file via cross-references

# models.py
class User:
    # AI! add a 'plan' field with type Literal["free", "pro"], default "free"
    name: str
    email: str

The AI! (with bang) tells Aider to act immediately even without a save trigger. Aider also updates tests/test_models.py if it imports User.

Bang variants

FAQ

Q: Does watch mode work in any editor? A: Yes — watch mode tails files at the filesystem level, so VS Code, vim, neovim, JetBrains, Cursor, even Claude Code's internal edits all trigger it. The editor doesn't matter.

Q: Will it edit files I didn't ask it to? A: Only files you've /add'd to Aider's session, or the file containing the AI comment. Files in no-edit are protected. Aider also asks before destructive operations (deleting, renaming) by default.

Q: Can I disable auto-commits in watch mode? A: Yes — auto-commits: false in your config. Aider still edits the files but leaves the changes uncommitted for you to review and commit manually.

Source & Thanks

Built by Paul Gauthier and the Aider community. Watch mode shipped in Aider 0.50.

Aider-AI/aider — ⭐ 36,000+