[Bug]: Tab in a composer numbered list keeps the number and does not nest the item in the sent Markdown #17124

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1. juliusmarminge commented on Oct 8, 2026

   

   juliusmarminge

   on Oct 8, 2026

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   Grok responding on behalf of Julius.

   Thanks for the detailed report. I checked it against current main (30cc78897), and the Tab and Shift+Enter parts hold up.

   What the code does (confirmed)

   • Tab: listIndentForTab always inserts " " at the start of the line and leaves the marker alone, so 2. stays 2. . The existing test only checks a bullet (- foo → - foo).
   • Both modes use it: the Tiptap editor passes Tab to the composer's key handler in plain and rich mode, and Tiptap's own list Tab/Shift-Tab are turned off. ChatComposer then calls listIndentForTab.
   • Why rich mode looks nested: the rich-text parser treats any deeper indent prefix as a child list, with no content-column check. Serialization then writes the stored indent back as typed. So the editor draws 1. first\n 2. nested as nested, but the prompt text that gets sent is exactly that string. I ran it through mdast-util-from-markdown with GFM (the same micromark stack react-markdown/remark-gfm use). "1. first\n 2. nested" comes out as one flat list with two items, and "1. first\n 1. nested" comes out nested. - a\n - b nests fine, as you said.
   • Plain-mode Shift+Enter on an empty item: listContinuationForEnter removes the marker no matter how deep the indent is. Rich mode handles list items through splitOrLiftListItem, which lifts an empty item one level. That's why the two modes behave differently.
   • Shift+Tab: ChatComposer toggles plan mode, or returns false when plan mode isn't available, which lets the browser move focus back. Nothing outdents a list item.

   The user docs say Tab nests a list item and that what you type is what the agent receives. That makes the flat result a bug and not intended behavior.

   Inferred / not verified

   • I didn't check how the sent message bubble renders this in the app. With the parser above it would likely show as a flat list.
   • How a given model reads 2. nested is outside our control. The sent text is simply not a nested list in CommonMark.

   Possible fix direction (untested)

   • Tab on a list line should indent to the item above's content column (marker width plus its following space, so 3 for 1. and 4 for 10. ). For ordered items it should restart at 1. or continue an existing sublist. Because rich mode serializes the stored indent, fixing the source edit would likely fix both modes.
   • Plain-mode Shift+Enter on an empty nested item could outdent to the parent's indent and continue the parent's numbering, matching what rich mode already does.
   • Whether Shift+Tab should outdent nested list lines is a separate maintainer call, since it changes the plan-mode shortcut on those lines. It isn't needed for the Tab/Shift+Enter fix.

   Related

   • fix(web): renumber following items when inserting into a numbered list #14332 (open): renumbers following items when you insert into a numbered list. It edits the same composer-list-continuation.ts functions and the same ChatComposer call site. It also adds a caret field to ComposerListEdit. Your branch adds one too, so the two would need reconciling. GitHub already shows fix(web): renumber following items when inserting into a numbered list #14332 as conflicting with main.
   • feat(web): block-level Markdown in the rich text composer #14677 (merged): added block-level Markdown to the rich composer, where the current list parsing and serialization live.
   • [Bug]: Message with numbers transforms into numbered list with wrong numbers #8394 (open, different issue: numbers in a message turning into a list) and feat(web): continue markdown lists and complete code fences in composer #12145 (closed, unmerged earlier list-continuation attempt).

   On scope, your fork branch is one commit. It touches composer-list-continuation.ts and its tests, ChatComposer.tsx, and docs/user/composer.md, which covers the Tab nesting, the Shift+Enter outdent, and the Shift+Tab outdent. I haven't run it.
2. juliusmarminge

   added

   bugSomething is broken or behaving incorrectly.Something is broken or behaving incorrectly.

   via-triageFiled through npx t3 triageFiled through npx t3 triage

   on Oct 8, 2026
3. michal-billtech

   added a commit that references this issue on Oct 8, 2026

   fix(web): Tab nests numbered list items in the composer

   ...

   This issue will close once commit 0b4e119 is merged into the 'main' branch.

   0b4e119