Comment on a line of a file

Agents: claude, codex, opencode · On: phone, desktop

Tap a line in the viewer, type what is wrong with it, and send it to the agent as a message that names the file, the line and quotes it.

Why you would use it

The agent wrote something you want changed, and "line 42 of runner.js, the timeout is too short" is easier to point at than to describe. The comment carries the line's text with it, so the agent does not have to guess.

How to use it

1. Open a file in the viewer.

2. Tap a line. A box opens under it: an avatar beside a text field with the placeholder comment on line <n>…. The avatar is the first letter of your VCode account's email, or Y when the computer is not linked to an account.

3. Type the comment.

   

4. Tap Comment to send it to the agent on its own, or Add to review / Start review to gather it with others (see review-a-file).

5. Tap Close to drop the box without sending. On a line that already has a comment the button reads Remove; tapping it takes the comment away.

What you see

• One box at a time, under the line it is about.
• Comment and the review button are disabled while the box is empty.
• A sent comment shows a toast: comment on line <n> sent.
• Offline, the message goes to the outbox and the toast reads offline — comment queued in outbox.
• If the send is refused for want of a login but kept in the outbox, the toast reads sign in — the comment is queued.
• If the send fails outright, the words are not lost: they are kept as a review comment and the toast reads <error> — kept as a review comment.

The message the agent receives:

Comment on lib/runner.js:42
> const TIMEOUT = 10_000;
this is too short for a cold start

Limits and known gaps

• One comment per line. Writing on a line that already has one rewords it; saving it empty removes it.
• Comments are for read mode only. In edit mode a tap puts the cursor on the line, and the cards come back when you tap Done.
• The quoted line is trimmed and cut at 200 characters, with … on the end.
• Tapping a removed line in the diff marks does nothing: it is not a line of the file as it is now.
• Tapping a link, an open box or an existing card does not open a new box, and neither does dragging out a text selection.
• The comment is sent with mode queue: it runs after the turn in progress. It does not carry the attachments waiting in the composer.
• A single comment sent from a line that was part of a gathered review is taken out of that review.

Related

• review-a-file — gather several comments and send them at once
• edit-a-file — change the line yourself instead of asking
• file-viewer — the sheet the lines live in
• viewer-diff-marks — why a removed line cannot be commented on
• queue-or-steer — what mode queue means for the turn
• queue-a-message-offline — where an offline comment waits