diff --git a/packages/app/src/agent-stream/layout.test.ts b/packages/app/src/agent-stream/layout.test.ts
index cf39b6920..fba61bdba 100644
--- a/packages/app/src/agent-stream/layout.test.ts
+++ b/packages/app/src/agent-stream/layout.test.ts
@@ -123,6 +123,43 @@ function findLayoutItem(layout: StreamLayout, id: string): StreamLayoutItem {
 }
 
 describe("layoutStream", () => {
+  it.each(["web", "android"] as const)(
+    "keeps split assistant block spacing identical to unsplit history on %s",
+    (platform) => {
+      const firstBlock = assistantMessage("turn:block:0", 2, { groupId: "turn", index: 0 });
+      const secondBlock = assistantMessage("turn:block:1", 3, { groupId: "turn", index: 1 });
+      const thirdBlock = assistantMessage("turn:block:2", 4, { groupId: "turn", index: 2 });
+      const splitLayout = layoutFor({
+        platform,
+        agentStatus: "running",
+        tail: [userMessage("u1", 1), firstBlock],
+        head: [secondBlock, thirdBlock],
+        timingIds: [firstBlock.id, secondBlock.id, thirdBlock.id],
+      });
+      const unsplitLayout = layoutFor({
+        platform,
+        agentStatus: "running",
+        tail: [userMessage("u1", 1), firstBlock, secondBlock, thirdBlock],
+        timingIds: [firstBlock.id, secondBlock.id, thirdBlock.id],
+      });
+
+      expect(findLayoutItem(splitLayout, firstBlock.id).belowItem?.id).toBe(secondBlock.id);
+      expect(findLayoutItem(splitLayout, secondBlock.id).aboveItem?.id).toBe(firstBlock.id);
+      expect(findLayoutItem(splitLayout, firstBlock.id).assistantSpacing).toBe(
+        findLayoutItem(unsplitLayout, firstBlock.id).assistantSpacing,
+      );
+      expect(findLayoutItem(splitLayout, secondBlock.id).assistantSpacing).toBe(
+        findLayoutItem(unsplitLayout, secondBlock.id).assistantSpacing,
+      );
+      expect(findLayoutItem(splitLayout, firstBlock.id).gapBelow).toBe(
+        findLayoutItem(unsplitLayout, firstBlock.id).gapBelow,
+      );
+      expect(findLayoutItem(splitLayout, secondBlock.id).gapBelow).toBe(
+        findLayoutItem(unsplitLayout, secondBlock.id).gapBelow,
+      );
+    },
+  );
+
   it("does not duplicate footers when a native assistant turn spans history and live head", () => {
     const historyBlock = assistantMessage("turn:block:0", 2, { groupId: "turn", index: 0 });
     const headBlock = assistantMessage("turn:head", 3, { groupId: "turn", index: 1 });
@@ -195,6 +232,39 @@ describe("layoutStream", () => {
     expect(findLayoutItem(layout, headBlock.id).assistantSpacing).toBe("compactTop");
   });
 
+  it.each(["web", "android"] as const)(
+    "keeps split tool sequencing and gapBelow identical to unsplit history on %s",
+    (platform) => {
+      const shell = toolCall("tool-1", 2);
+      const thinking = thought("thought-1", 3);
+      const assistant = assistantMessage("a1", 4);
+      const splitLayout = layoutFor({
+        platform,
+        tail: [userMessage("u1", 1), shell],
+        head: [thinking, assistant],
+      });
+      const unsplitLayout = layoutFor({
+        platform,
+        tail: [userMessage("u1", 1), shell, thinking, assistant],
+      });
+
+      expect(findLayoutItem(splitLayout, shell.id).belowItem?.id).toBe(thinking.id);
+      expect(findLayoutItem(splitLayout, thinking.id).aboveItem?.id).toBe(shell.id);
+      expect(findLayoutItem(splitLayout, shell.id).toolSequence).toBe(
+        findLayoutItem(unsplitLayout, shell.id).toolSequence,
+      );
+      expect(findLayoutItem(splitLayout, thinking.id).toolSequence).toBe(
+        findLayoutItem(unsplitLayout, thinking.id).toolSequence,
+      );
+      expect(findLayoutItem(splitLayout, shell.id).gapBelow).toBe(
+        findLayoutItem(unsplitLayout, shell.id).gapBelow,
+      );
+      expect(findLayoutItem(splitLayout, thinking.id).gapBelow).toBe(
+        findLayoutItem(unsplitLayout, thinking.id).gapBelow,
+      );
+    },
+  );
+
   it("computes tool sequence position from strategy-aware neighbors", () => {
     const shell = toolCall("tool-1", 2);
     const thinking = thought("thought-1", 3);
diff --git a/packages/app/src/agent-stream/layout.ts b/packages/app/src/agent-stream/layout.ts
index de0fe38f9..1c6e83882 100644
--- a/packages/app/src/agent-stream/layout.ts
+++ b/packages/app/src/agent-stream/layout.ts
@@ -32,7 +32,6 @@ export interface StreamLayout {
   history: StreamLayoutItem[];
   liveHead: StreamLayoutItem[];
   auxiliaryTurnFooter: TurnFooterHost | null;
-  historyToHeadGap: number;
 }
 
 export interface StreamLayoutInput {
@@ -243,6 +242,5 @@ export function layoutStream(input: StreamLayoutInput): StreamLayout {
     history,
     liveHead,
     auxiliaryTurnFooter,
-    historyToHeadGap: getGapBetweenStreamItems(historyBoundaryItem, liveHeadBoundaryItem),
   };
 }
diff --git a/packages/app/src/agent-stream/model.ts b/packages/app/src/agent-stream/model.ts
index 20f1f787c..fe92e63fc 100644
--- a/packages/app/src/agent-stream/model.ts
+++ b/packages/app/src/agent-stream/model.ts
@@ -19,7 +19,6 @@ export interface StreamHistoryBoundary {
   hasVirtualizedHistory: boolean;
   hasMountedHistory: boolean;
   hasLiveHead: boolean;
-  historyToHeadGap: number;
 }
 
 export interface StreamRenderAuxiliary {
@@ -205,7 +204,6 @@ export function buildAgentStreamRenderModel(
       hasVirtualizedHistory: splitHistory.segments.historyVirtualized.length > 0,
       hasMountedHistory: splitHistory.segments.historyMounted.length > 0,
       hasLiveHead: orderedHead.length > 0,
-      historyToHeadGap: 0,
     },
     auxiliary: EMPTY_AUXILIARY,
   };
diff --git a/packages/app/src/agent-stream/strategy-web.test.tsx b/packages/app/src/agent-stream/strategy-web.test.tsx
index b4e14f895..3a689a866 100644
--- a/packages/app/src/agent-stream/strategy-web.test.tsx
+++ b/packages/app/src/agent-stream/strategy-web.test.tsx
@@ -125,7 +125,6 @@ describe("createWebStreamStrategy", () => {
               hasVirtualizedHistory: true,
               hasMountedHistory: false,
               hasLiveHead: false,
-              historyToHeadGap: 0,
             },
             renderers: createRenderers(rowRenderCount),
             listEmptyComponent: null,
@@ -171,7 +170,6 @@ describe("createWebStreamStrategy", () => {
               hasVirtualizedHistory: false,
               hasMountedHistory: true,
               hasLiveHead: false,
-              historyToHeadGap: 0,
             },
             renderers: createRenderers(vi.fn()),
             listEmptyComponent: null,
diff --git a/packages/app/src/agent-stream/strategy-web.tsx b/packages/app/src/agent-stream/strategy-web.tsx
index 3053aded0..7f5bea596 100644
--- a/packages/app/src/agent-stream/strategy-web.tsx
+++ b/packages/app/src/agent-stream/strategy-web.tsx
@@ -584,9 +584,6 @@ function WebStreamViewport(props: StreamRenderInput & { isMobileBreakpoint: bool
             </div>
           ) : null}
           {mountedHistoryRows}
-          {boundary.hasMountedHistory && boundary.hasLiveHead && boundary.historyToHeadGap > 0 ? (
-            <HistoryToHeadSpacer height={boundary.historyToHeadGap} />
-          ) : null}
           {liveHeadRows}
           {liveAuxiliary}
           {shouldRenderEmpty ? listEmptyComponent : null}
@@ -634,12 +631,3 @@ export function createWebStreamStrategy(input: CreateWebStreamStrategyInput): St
     getBottomOffset: (metrics) => Math.max(0, metrics.contentHeight - metrics.viewportHeight),
   });
 }
-
-interface HistoryToHeadSpacerProps {
-  height: number;
-}
-
-function HistoryToHeadSpacer({ height }: HistoryToHeadSpacerProps) {
-  const spacerStyle = useMemo(() => ({ height, width: "100%" as const }), [height]);
-  return <div style={spacerStyle} />;
-}
diff --git a/packages/app/src/agent-stream/view.tsx b/packages/app/src/agent-stream/view.tsx
index 372c66eb3..57f17970d 100644
--- a/packages/app/src/agent-stream/view.tsx
+++ b/packages/app/src/agent-stream/view.tsx
@@ -613,16 +613,13 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
     const renderModel = useMemo<AgentStreamRenderModel>(() => {
       return {
         ...baseRenderModel,
-        boundary: {
-          ...baseRenderModel.boundary,
-          historyToHeadGap: streamLayout.historyToHeadGap,
-        },
+        boundary: baseRenderModel.boundary,
         auxiliary: {
           pendingPermissions: pendingPermissionsNode,
           turnFooter: turnFooterNode,
         },
       };
-    }, [baseRenderModel, pendingPermissionsNode, streamLayout.historyToHeadGap, turnFooterNode]);
+    }, [baseRenderModel, pendingPermissionsNode, turnFooterNode]);
 
     const emptyStateStyle = useMemo(() => [stylesheet.emptyState, stylesheet.contentWrapper], []);
     const listEmptyComponent = useMemo(