feat(web): absorb intermediate agent text into tool groups

Intermediate agent text/thought rows between tool calls in the same
turn now render inside the collapsed tool group instead of after it,
preserving chronological order. The last agent text (no subsequent
tool) stays outside as the prominent final answer.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/structured.test.ts

@@ -413,6 +413,39 @@ describe("structured connection: data flow", () => {
     conn.dispose();
   });
 
+  it("absorbs intermediate agent text into tool group, keeps final text outside", () => {
+    const ws = new FakeSocket();
+    const conn = mount({ sockets: [ws] });
+    ws.open();
+    ws.emit({
+      type: "transcript_snapshot",
+      snapshot: {
+        cursor: 8,
+        rows: [
+          row("user:1", "user", { content: { type: "text", text: "do it" } }),
+          row("agent:1", "agent_text", { content: { type: "text", text: "Let me check" } }),
+          toolRow("tool:1", "one"),
+          toolRow("tool:2", "two"),
+          row("agent:2", "agent_text", { content: { type: "text", text: "Found issues, fixing" } }),
+          toolRow("tool:3", "three"),
+          toolRow("tool:4", "four"),
+          row("agent:3", "agent_text", { content: { type: "text", text: "All done" } }),
+        ],
+      },
+    });
+    const groups = conn.el.querySelectorAll<HTMLElement>(".st-tool-group");
+    expect(groups).toHaveLength(1);
+    // Header counts only tool rows, not intermediate text.
+    expect(groups[0].querySelector(".st-tool-group-head")!.textContent).toContain("4 tool calls");
+    // Intermediate text (agent:2) is inside the group.
+    expect(conn.el.querySelector('[data-row-id="agent:2"]')?.closest(".st-tool-group")).not.toBeNull();
+    // First text (agent:1) is outside — it precedes all tools.
+    expect(conn.el.querySelector('[data-row-id="agent:1"]')?.closest(".st-tool-group")).toBeNull();
+    // Final text (agent:3) is outside — no tool follows it.
+    expect(conn.el.querySelector('[data-row-id="agent:3"]')?.closest(".st-tool-group")).toBeNull();
+    conn.dispose();
+  });
+
   it("keeps an expanded running tool open without emitting a click when patched", () => {
     const ws = new FakeSocket();
     const conn = mount({ sockets: [ws] });

web/src/structured.ts

@@ -393,17 +393,53 @@ export function createStructuredConnection(
     return el;
   }
 
-  function toolGroupsByTurn(): Map<string, TranscriptRow[]> {
-    const groups = new Map<string, TranscriptRow[]>();
+  /** Group tool rows (and intermediate agent text between them) by turn.
+   *  An agent_text/agent_thought row is "intermediate" when a tool row follows
+   *  it in the same turn — it gets absorbed into the group so the collapsed
+   *  block preserves chronological order.  The *last* agent text with no
+   *  subsequent tool stays standalone (the prominent final answer).
+   *  Returns groups keyed by `turn:<userId>`, each with `toolCount` (for the
+   *  header label) and `rows` (tools + intermediate text, in order). */
+  function activityGroupsByTurn(): Map<string, { toolCount: number; rows: TranscriptRow[] }> {
+    // First: count tools per turn to know which turns qualify for grouping.
+    const toolCounts = new Map<string, number>();
     let turnId = "before-first-message";
     for (const row of rows) {
       if (row.kind === "user") turnId = row.id;
       if (row.kind !== "tool_call" && row.kind !== "tool_diff") continue;
-      const id = `turn:${turnId}`;
-      const group = groups.get(id) ?? [];
-      group.push(row);
-      groups.set(id, group);
+      const gid = `turn:${turnId}`;
+      toolCounts.set(gid, (toolCounts.get(gid) ?? 0) + 1);
     }
+    // Second: build groups with interleaved text for turns with 2+ tools.
+    const groups = new Map<string, { toolCount: number; rows: TranscriptRow[] }>();
+    turnId = "before-first-message";
+    // Pending text rows that might be intermediate (not yet confirmed by a
+    // following tool). If no tool follows, they stay standalone.
+    let pendingText: TranscriptRow[] = [];
+    let currentGid = `turn:${turnId}`;
+    for (const row of rows) {
+      if (row.kind === "user") {
+        turnId = row.id;
+        currentGid = `turn:${turnId}`;
+        pendingText = [];
+        continue;
+      }
+      const count = toolCounts.get(currentGid) ?? 0;
+      if (count < 2) continue;
+      if (row.kind === "agent_text" || row.kind === "agent_thought") {
+        pendingText.push(row);
+        continue;
+      }
+      if (row.kind === "tool_call" || row.kind === "tool_diff") {
+        const group = groups.get(currentGid) ?? { toolCount: count, rows: [] };
+        // Flush any pending text — a tool follows, so it's intermediate.
+        group.rows.push(...pendingText);
+        pendingText = [];
+        group.rows.push(row);
+        groups.set(currentGid, group);
+      }
+    }
+    // pendingText at end of a turn = final text, stays outside (not flushed).
     return groups;
   }
 
@@ -413,9 +449,9 @@ export function createStructuredConnection(
     const focusedGroupId = active?.closest<HTMLElement>("[data-tool-group-id]")?.dataset.toolGroupId;
     const restoreToolFocus = active?.classList.contains("st-tool-head") ?? false;
     const restoreGroupFocus = active?.classList.contains("st-tool-group-head") ?? false;
-    const groups = toolGroupsByTurn();
+    const groups = activityGroupsByTurn();
     const groupedRowIds = new Set<string>();
-    const liveGroupIds = new Set([...groups].filter(([, tools]) => tools.length > 1).map(([id]) => id));
+    const liveGroupIds = new Set([...groups.keys()]);
     for (const id of expandedGroupIds) if (!liveGroupIds.has(id)) expandedGroupIds.delete(id);
 
     rowEls.clear();
@@ -425,28 +461,30 @@ export function createStructuredConnection(
     for (const row of rows) {
       if (row.kind === "user") turnId = row.id;
       const groupId = `turn:${turnId}`;
-      const groupRows = groups.get(groupId) ?? [];
-      if ((row.kind === "tool_call" || row.kind === "tool_diff") && groupRows.length > 1) {
-        if (groupedRowIds.has(row.id)) continue;
-        const toolEls = groupRows.flatMap((toolRow) => {
-          groupedRowIds.add(toolRow.id);
-          const toolEl = buildRowElement(toolRow);
-          if (!toolEl) return [];
-          rowEls.set(toolRow.id, toolEl);
-          return [toolEl];
+      const group = groups.get(groupId);
+      if (group && groupedRowIds.has(row.id)) continue;
+      if (group && (row.kind === "tool_call" || row.kind === "tool_diff") && !groupedRowIds.has(row.id)) {
+        // First ungrouped tool in this turn — render the whole activity group.
+        const memberEls = group.rows.flatMap((memberRow) => {
+          groupedRowIds.add(memberRow.id);
+          const memberEl = buildRowElement(memberRow);
+          if (!memberEl) return [];
+          rowEls.set(memberRow.id, memberEl);
+          return [memberEl];
         });
         const groupEl = buildToolGroup(
           groupId,
-          groupRows,
-          toolEls,
+          group.rows,
+          memberEls,
           expandedGroupIds.has(groupId),
           (expanded) => {
             if (expanded) expandedGroupIds.add(groupId);
             else expandedGroupIds.delete(groupId);
             settleDisclosureLayout();
           },
+          group.toolCount,
         );
-        if (groupRows.some((toolRow) => enteringRowIds.has(toolRow.id))) {
+        if (group.rows.some((r) => enteringRowIds.has(r.id))) {
           groupEl.classList.add("st-row-enter");
         }
         groupEls.set(groupId, groupEl);

web/src/structuredRender.ts

@@ -581,7 +581,9 @@ export function buildToolGroup(
   children: HTMLElement[],
   expanded: boolean,
   onExpandedChange?: (expanded: boolean) => void,
+  toolCount?: number,
 ): HTMLElement {
+  const count = toolCount ?? rows.length;
   const wrap = el("div", "st-tool-group");
   wrap.dataset.toolGroupId = id;
   const head = document.createElement("button");
@@ -593,7 +595,7 @@ export function buildToolGroup(
   glyph.textContent = "›";
   glyph.setAttribute("aria-hidden", "true");
   const title = el("span", "st-tool-group-title");
-  title.textContent = `${rows.length} tool calls`;
+  title.textContent = `${count} tool calls`;
   head.append(glyph, title);
 
   const body = el("div", "st-tool-group-body st-disclosure");

web/src/styles.css

@@ -2895,6 +2895,26 @@ input.leaf-rename:focus {
   border-radius: var(--r-1);
 }
 
+/* intermediate agent text inside a tool group — subdued so the final
+   answer outside the group stays the prominent one. */
+.st-tool-group-body .st-row-agent {
+  color: var(--muted);
+  font-size: var(--fs-12);
+  padding: var(--sp-1) var(--sp-2);
+}
+
+.st-tool-group-body .st-row-agent .st-body > :first-child {
+  margin-top: 0;
+}
+
+.st-tool-group-body .st-row-agent .st-body > :last-child {
+  margin-bottom: 0;
+}
+
+.st-tool-group-body .st-row-thought {
+  padding: var(--sp-1) var(--sp-2);
+}
+
 .st-tool-group-body[hidden] {
   display: none;
 }