Document edit pipeline can't speak formatting.

Most failed tests reduce to one schema-shaped hole. The editor already supports format-only suggestions; the API just never sends them.

27 test scenarios + email-group (5 untestable in dev: no email integration set up).

1. What broke — at a glance

2. The architectural wall

The pipeline from user message to editor crosses six boundaries. Three of them enforce the same five-command vocabulary. The seventh (the editor extension) already speaks formatting — it just never gets asked.

3. The two lines of code that explain everything

export const EditCommandSchema = z.discriminatedUnion("type", [
  EditCommandShape,      // type: "edit"
  InsertCommandShape,    // type: "insert"
  DeleteCommandShape,    // type: "delete"
  RefineCommandShape,    // type: "refine"
  WithdrawCommandShape,  // type: "withdraw"
])
// None of the shapes carry marks, attrs,
// heading level, alignment, indent or list ops.

  return {
    id: randomUUID(),
    originalText,
    suggestedText,
    comment: params.comment ?? null,
    revisionId: params.revisionId ?? null,
    author: params.author ?? AGENT_AUTHOR_NAME,
    date,
    source: "user",
    formatChange: null,   // ⚠ hardcoded
  }

4. Why "remove formatting" wiped the typeface

case "replace": {
  const from = map(plan.operation.from)
  const to = map(plan.operation.to)
  const { newText, attrs } = plan.operation
  tr.delete(from, to)
  tr.insertText(newText, from)  // no marks
  const mark = diffSuggestionMarkType.create(attrs)
  tr.addMark(from, from + newText.length, mark)
}

case "replace": {
  const from = map(plan.operation.from)
  const to = map(plan.operation.to)
  const { newText, attrs } = plan.operation
  const inherited = tr.doc.resolve(from).marks()
  tr.delete(from, to)
  tr.insertText(newText, from)
  inherited.forEach(m => tr.addMark(from, from + newText.length, m))
  const mark = diffSuggestionMarkType.create(attrs)
  tr.addMark(from, from + newText.length, mark)
}

5. The agent diagnosed itself, accurately

By the third or fourth failed attempt the agent reasoned its way to the gap. Direct quotes from Langfuse:

trace 6 · response to "does your edit dsl support formatting?"

"Looking honestly at the tool's capabilities: the edit tool for documents works by finding and replacing text, and applying marks to the replaced text requires the replace content to carry the formatting inline. Unfortunately, the current document edit surface doesn't expose a mechanism to apply a bold mark…"

trace 13 · response to "make section 6 list into a numbered list?"

"I can see the full bullet list structure. I can replace the entire bulletList block with an orderedList — let me do that now. The edit tool doesn't support replacing a block node with a different node type — the replace field only accepts a string, not a full ProseMirror node structure."

trace 17 · after testing block_attrs by user request

"Thanks for testing that — so block_attrs isn't honoured by the edit surface. Can do: find & replace text, insert new blocks, strip formatting. Cannot: apply inline marks (bold/italic/underline), apply font, font size, change indentation, convert list types."

6. Adjacent issues (independent fixes)

2026-05-11T17:21:32.163916: how about font size?

7. Trace timeline (26 turns · 31 minutes)

8. Fix sequence — by impact & effort

9. Appendix — verification artifacts