Cite: show which citation each part of a reply is answering

[cornishandy]

I really like how Cite works. I select a passage in an assistant reply, add a question or comment, and it goes into the composer as a chip. After I send, clicking a chip in my message opens a popover with the quote, my comment and Go to source (#15703).

The gap is in the reply: it doesn't show which citation each part of it is answering.

Where it hurts

I often work through a long reply by citing a dozen or more passages, each with a short question or note. The agent answers them in order as "1.", "2.", "3." and so on. To read answer 7 properly, I have to:

1. scroll up to my sent message,
2. count the chips to find the 7th,
3. click it to see what I highlighted and what I asked,
4. scroll back down and find answer 7 again.

Then I do it all again for answer 8. With many citations, I spend more time going back and forth than reading the answers.

Request

Show the same chip in the reply, at the start of the part that answers each citation. Clicking it would open the same popover as in the sent message, with the highlighted text, my comment and Go to source. Each answer would then carry its own context, and I could stay in the reply.

How it might work

Only the agent knows which part of its reply answers which citation, so it has to say so. Most of the pieces seem to be there already:

• expandAssistantCitationsForProvider gives each citation an id (assistant-quote-1, assistant-quote-2, …) and puts an [assistant-quote-N] marker in the prompt where each chip was.
• ChatMarkdown turns any valid t3-citation:// link into an AssistantCitationChip, so a reply can already show the chip.

The note in <assistant_citations> could invite the agent to start its answer to a citation with that citation's [assistant-quote-N] marker. T3 would then render each marker in the reply as the chip for that citation, taken from the user message it answers. A reply without markers would look the same as today.

Related

#17520 asks for matching numbers on the quoted passage, the composer chip and the sent chip. That would end the counting, but I'd still have to scroll up and click a chip to see what an answer is about. This request is about the reply itself.

Seen on T3 Code Nightly 0.0.46-nightly.20261012.3021 (macOS desktop).