diff --git a/apps/web/src/components/chat/ChatComposer.tsx b/apps/web/src/components/chat/ChatComposer.tsx
index 5072c5870a7375020a8b5f1d7c3e5a9d6fc459ea..afba1e086b8434419814291449c34998fbe838df 100644
--- a/apps/web/src/components/chat/ChatComposer.tsx
+++ b/apps/web/src/components/chat/ChatComposer.tsx
@@ -407,6 +407,7 @@ const ComposerFooterPrimaryActions = memo(function ComposerFooterPrimaryActions(
   isEnvironmentUnavailable: boolean;
   hasSendableContent: boolean;
   preserveComposerFocusOnPointerDown?: boolean;
+  showSendWhileRunning?: boolean;
   onPreviousPendingQuestion: () => void;
   onInterrupt: () => void;
   onImplementPlanInNewThread: () => void;
@@ -435,6 +436,7 @@ const ComposerFooterPrimaryActions = memo(function ComposerFooterPrimaryActions(
         isPreparingWorktree={props.isPreparingWorktree}
         hasSendableContent={props.hasSendableContent}
         preserveComposerFocusOnPointerDown={props.preserveComposerFocusOnPointerDown ?? false}
+        showSendWhileRunning={props.showSendWhileRunning ?? false}
         onPreviousPendingQuestion={props.onPreviousPendingQuestion}
         onInterrupt={props.onInterrupt}
         onImplementPlanInNewThread={props.onImplementPlanInNewThread}
@@ -3166,6 +3168,7 @@ export const ChatComposer = memo(function ChatComposer(props: ChatComposerProps)
                   isPreparingWorktree={isPreparingWorktree}
                   hasSendableContent={composerSendState.hasSendableContent}
                   preserveComposerFocusOnPointerDown={isMobileViewport}
+                  showSendWhileRunning={isMobileViewport}
                   onPreviousPendingQuestion={onPreviousActivePendingUserInputQuestion}
                   onInterrupt={handleInterruptPrimaryAction}
                   onImplementPlanInNewThread={handleImplementPlanInNewThreadPrimaryAction}
diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.test.ts b/apps/web/src/components/chat/ComposerPrimaryActions.test.ts
deleted file mode 100644
index 3dbcd39e9d13c10208b70e06ec451f6b4918edd8..0000000000000000000000000000000000000000
--- a/apps/web/src/components/chat/ComposerPrimaryActions.test.ts
+++ /dev/null
@@ -1,218 +0,0 @@
-import { createElement } from "react";
-import { renderToStaticMarkup } from "react-dom/server";
-import { afterEach, describe, expect, it, vi } from "vite-plus/test";
-
-const stageArtworkState = vi.hoisted(() => ({
-  mode: "none" as "artwork" | "none",
-  variant: null as "nightly" | "dev" | null,
-}));
-
-vi.mock("~/hooks/useSettings", () => ({
-  useEnvironmentIdentificationMode: () => stageArtworkState.mode,
-}));
-vi.mock("../SidebarStageBackdrop", () => ({
-  StageBackdropButtonArt: ({ variant }: { variant: string }) => `stage-${variant}`,
-  useSidebarStageBackdropVariant: (enabled = true) => (enabled ? stageArtworkState.variant : null),
-}));
-
-import { ComposerPrimaryActions, formatPendingPrimaryActionLabel } from "./ComposerPrimaryActions";
-
-function renderPendingActions(isRunning: boolean) {
-  return renderToStaticMarkup(
-    createElement(ComposerPrimaryActions, {
-      compact: true,
-      pendingAction: {
-        questionIndex: 0,
-        isLastQuestion: true,
-        canAdvance: true,
-        isResponding: false,
-        isComplete: true,
-      },
-      isRunning,
-      showPlanFollowUpPrompt: false,
-      promptHasText: false,
-      isSendBusy: false,
-      sendDisabledReason: null,
-      isConnecting: false,
-      isEnvironmentUnavailable: false,
-      isPreparingWorktree: false,
-      hasSendableContent: false,
-      onPreviousPendingQuestion: () => {},
-      onInterrupt: () => {},
-      onImplementPlanInNewThread: () => {},
-    }),
-  );
-}
-
-function renderStandaloneStop() {
-  return renderToStaticMarkup(
-    createElement(ComposerPrimaryActions, {
-      compact: true,
-      pendingAction: null,
-      isRunning: true,
-      showPlanFollowUpPrompt: false,
-      promptHasText: false,
-      isSendBusy: false,
-      sendDisabledReason: null,
-      isConnecting: false,
-      isEnvironmentUnavailable: false,
-      isPreparingWorktree: false,
-      hasSendableContent: false,
-      onPreviousPendingQuestion: () => {},
-      onInterrupt: () => {},
-      onImplementPlanInNewThread: () => {},
-    }),
-  );
-}
-
-function renderSendButton() {
-  return renderToStaticMarkup(
-    createElement(ComposerPrimaryActions, {
-      compact: true,
-      pendingAction: null,
-      isRunning: false,
-      showPlanFollowUpPrompt: false,
-      promptHasText: true,
-      isSendBusy: false,
-      sendDisabledReason: null,
-      isConnecting: false,
-      isEnvironmentUnavailable: false,
-      isPreparingWorktree: false,
-      hasSendableContent: true,
-      onPreviousPendingQuestion: () => {},
-      onInterrupt: () => {},
-      onImplementPlanInNewThread: () => {},
-    }),
-  );
-}
-
-afterEach(() => {
-  stageArtworkState.mode = "none";
-  stageArtworkState.variant = null;
-});
-
-describe("formatPendingPrimaryActionLabel", () => {
-  it("returns 'Submitting...' while responding", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: false,
-        isLastQuestion: false,
-        isResponding: true,
-        questionIndex: 0,
-      }),
-    ).toBe("Submitting...");
-  });
-
-  it("returns 'Submitting...' while responding regardless of other flags", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: true,
-        isLastQuestion: true,
-        isResponding: true,
-        questionIndex: 3,
-      }),
-    ).toBe("Submitting...");
-  });
-
-  it("returns 'Submit' in compact mode on the last question", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: true,
-        isLastQuestion: true,
-        isResponding: false,
-        questionIndex: 0,
-      }),
-    ).toBe("Submit");
-  });
-
-  it("returns 'Next' in compact mode when not the last question", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: true,
-        isLastQuestion: false,
-        isResponding: false,
-        questionIndex: 1,
-      }),
-    ).toBe("Next");
-  });
-
-  it("returns 'Next question' when not the last question", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: false,
-        isLastQuestion: false,
-        isResponding: false,
-        questionIndex: 0,
-      }),
-    ).toBe("Next question");
-  });
-
-  it("returns singular 'Submit answer' on the last question when it is the only question", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: false,
-        isLastQuestion: true,
-        isResponding: false,
-        questionIndex: 0,
-      }),
-    ).toBe("Submit answer");
-  });
-
-  it("returns plural 'Submit answers' on the last question when there are multiple questions", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: false,
-        isLastQuestion: true,
-        isResponding: false,
-        questionIndex: 1,
-      }),
-    ).toBe("Submit answers");
-  });
-
-  it("returns plural 'Submit answers' for higher question indices", () => {
-    expect(
-      formatPendingPrimaryActionLabel({
-        compact: false,
-        isLastQuestion: true,
-        isResponding: false,
-        questionIndex: 5,
-      }),
-    ).toBe("Submit answers");
-  });
-});
-
-describe("ComposerPrimaryActions", () => {
-  it("offers Stop generation while a running turn is waiting for user input", () => {
-    expect(renderPendingActions(true)).toContain('aria-label="Stop generation"');
-  });
-
-  it("does not offer Stop generation for a pending request without a running turn", () => {
-    expect(renderPendingActions(false)).not.toContain('aria-label="Stop generation"');
-  });
-
-  it("matches the small pending action size without changing the standalone size", () => {
-    expect(renderPendingActions(true)).toContain("size-8 sm:size-7");
-    expect(renderStandaloneStop()).toContain("size-8 sm:h-8 sm:w-8");
-    expect(renderStandaloneStop()).not.toContain("sm:size-7");
-  });
-
-  it("renders stage artwork inside the send button when artwork identification is active", () => {
-    stageArtworkState.mode = "artwork";
-    stageArtworkState.variant = "nightly";
-
-    const markup = renderSendButton();
-
-    expect(markup).toContain("stage-nightly");
-    expect(markup).toContain("bg-transparent text-white");
-    expect(markup).not.toContain("bg-message-action text-message-action-foreground");
-  });
-
-  it("keeps the normal send-button fill when artwork identification is inactive", () => {
-    stageArtworkState.variant = "nightly";
-
-    const markup = renderSendButton();
-
-    expect(markup).not.toContain("stage-nightly");
-    expect(markup).toContain("bg-message-action text-message-action-foreground");
-  });
-});
diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.test.tsx b/apps/web/src/components/chat/ComposerPrimaryActions.test.tsx
new file mode 100644
index 0000000000000000000000000000000000000000..c48f029f7f9bf55b158c85da33afebef3cf794d8
--- /dev/null
+++ b/apps/web/src/components/chat/ComposerPrimaryActions.test.tsx
@@ -0,0 +1,263 @@
+import { createElement } from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { afterEach, describe, expect, it, vi } from "vite-plus/test";
+
+const stageArtworkState = vi.hoisted(() => ({
+  mode: "none" as "artwork" | "none",
+  variant: null as "nightly" | "dev" | null,
+}));
+
+vi.mock("~/hooks/useSettings", () => ({
+  useEnvironmentIdentificationMode: () => stageArtworkState.mode,
+}));
+vi.mock("../SidebarStageBackdrop", () => ({
+  StageBackdropButtonArt: ({ variant }: { variant: string }) => `stage-${variant}`,
+  useSidebarStageBackdropVariant: (enabled = true) => (enabled ? stageArtworkState.variant : null),
+}));
+
+import { ComposerPrimaryActions, formatPendingPrimaryActionLabel } from "./ComposerPrimaryActions";
+
+function renderPendingActions(isRunning: boolean) {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: {
+        questionIndex: 0,
+        isLastQuestion: true,
+        canAdvance: true,
+        isResponding: false,
+        isComplete: true,
+      },
+      isRunning,
+      showPlanFollowUpPrompt: false,
+      promptHasText: false,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent: false,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
+
+function renderStandaloneStop() {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: null,
+      isRunning: true,
+      showPlanFollowUpPrompt: false,
+      promptHasText: false,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent: false,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
+
+function renderRunningActions(showSendWhileRunning: boolean, hasSendableContent: boolean) {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: null,
+      isRunning: true,
+      showPlanFollowUpPrompt: false,
+      promptHasText: hasSendableContent,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent,
+      showSendWhileRunning,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
+
+function renderSendButton() {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: null,
+      isRunning: false,
+      showPlanFollowUpPrompt: false,
+      promptHasText: true,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent: true,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
+
+afterEach(() => {
+  stageArtworkState.mode = "none";
+  stageArtworkState.variant = null;
+});
+
+describe("formatPendingPrimaryActionLabel", () => {
+  it("returns 'Submitting...' while responding", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: false,
+        isLastQuestion: false,
+        isResponding: true,
+        questionIndex: 0,
+      }),
+    ).toBe("Submitting...");
+  });
+
+  it("returns 'Submitting...' while responding regardless of other flags", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: true,
+        isLastQuestion: true,
+        isResponding: true,
+        questionIndex: 3,
+      }),
+    ).toBe("Submitting...");
+  });
+
+  it("returns 'Submit' in compact mode on the last question", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: true,
+        isLastQuestion: true,
+        isResponding: false,
+        questionIndex: 0,
+      }),
+    ).toBe("Submit");
+  });
+
+  it("returns 'Next' in compact mode when not the last question", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: true,
+        isLastQuestion: false,
+        isResponding: false,
+        questionIndex: 1,
+      }),
+    ).toBe("Next");
+  });
+
+  it("returns 'Next question' when not the last question", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: false,
+        isLastQuestion: false,
+        isResponding: false,
+        questionIndex: 0,
+      }),
+    ).toBe("Next question");
+  });
+
+  it("returns singular 'Submit answer' on the last question when it is the only question", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: false,
+        isLastQuestion: true,
+        isResponding: false,
+        questionIndex: 0,
+      }),
+    ).toBe("Submit answer");
+  });
+
+  it("returns plural 'Submit answers' on the last question when there are multiple questions", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: false,
+        isLastQuestion: true,
+        isResponding: false,
+        questionIndex: 1,
+      }),
+    ).toBe("Submit answers");
+  });
+
+  it("returns plural 'Submit answers' for higher question indices", () => {
+    expect(
+      formatPendingPrimaryActionLabel({
+        compact: false,
+        isLastQuestion: true,
+        isResponding: false,
+        questionIndex: 5,
+      }),
+    ).toBe("Submit answers");
+  });
+});
+
+describe("ComposerPrimaryActions", () => {
+  it("offers Stop generation while a running turn is waiting for user input", () => {
+    expect(renderPendingActions(true)).toContain('aria-label="Stop generation"');
+  });
+
+  it("does not offer Stop generation for a pending request without a running turn", () => {
+    expect(renderPendingActions(false)).not.toContain('aria-label="Stop generation"');
+  });
+
+  it("matches the small pending action size without changing the standalone size", () => {
+    expect(renderPendingActions(true)).toContain("size-8 sm:size-7");
+    expect(renderStandaloneStop()).toContain("size-8 sm:h-8 sm:w-8");
+    expect(renderStandaloneStop()).not.toContain("sm:size-7");
+  });
+
+  it("renders stage artwork inside the send button when artwork identification is active", () => {
+    stageArtworkState.mode = "artwork";
+    stageArtworkState.variant = "nightly";
+
+    const markup = renderSendButton();
+
+    expect(markup).toContain("stage-nightly");
+    expect(markup).toContain("bg-transparent text-white");
+    expect(markup).not.toContain("bg-message-action text-message-action-foreground");
+  });
+
+  it("keeps the normal send-button fill when artwork identification is inactive", () => {
+    stageArtworkState.variant = "nightly";
+
+    const markup = renderSendButton();
+
+    expect(markup).not.toContain("stage-nightly");
+    expect(markup).toContain("bg-message-action text-message-action-foreground");
+  });
+
+  it("only renders stop while running when Enter-to-send is available", () => {
+    const markup = renderRunningActions(false, true);
+
+    expect(markup).toContain('aria-label="Stop generation"');
+    expect(markup).not.toContain('aria-label="Send message"');
+  });
+
+  it("renders send alongside stop while running when Enter-to-send is unavailable", () => {
+    const markup = renderRunningActions(true, true);
+
+    expect(markup).toContain('aria-label="Stop generation"');
+    expect(markup).toContain('aria-label="Send message"');
+    expect(markup).toContain('type="submit"');
+    expect(markup).toContain("size-9 sm:size-8");
+  });
+
+  it("keeps stop as the only action while running with an empty composer", () => {
+    const markup = renderRunningActions(true, false);
+
+    expect(markup).toContain('aria-label="Stop generation"');
+    expect(markup).not.toContain('aria-label="Send message"');
+  });
+});
diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.tsx b/apps/web/src/components/chat/ComposerPrimaryActions.tsx
index d8626496ae7d8c8a88e110447228da6f59932f65..2a27796d92a51802fb217f0fa8302ffe1e7d0b62 100644
--- a/apps/web/src/components/chat/ComposerPrimaryActions.tsx
+++ b/apps/web/src/components/chat/ComposerPrimaryActions.tsx
@@ -28,6 +28,9 @@ interface ComposerPrimaryActionsProps {
   isPreparingWorktree: boolean;
   hasSendableContent: boolean;
   preserveComposerFocusOnPointerDown?: boolean;
+  /** Enter-to-send is disabled on mobile viewports, where stop would otherwise
+   * be the only primary action and a running turn could not be steered. */
+  showSendWhileRunning?: boolean;
   onPreviousPendingQuestion: () => void;
   onInterrupt: () => void;
   onImplementPlanInNewThread: () => void;
@@ -68,6 +71,7 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
   isPreparingWorktree,
   hasSendableContent,
   preserveComposerFocusOnPointerDown = false,
+  showSendWhileRunning = false,
   onPreviousPendingQuestion,
   onInterrupt,
   onImplementPlanInNewThread,
@@ -86,7 +90,11 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
       type="button"
       className={cn(
         "flex cursor-pointer items-center justify-center rounded-full bg-destructive/90 text-white shadow-xs shadow-destructive/24 inset-shadow-[0_1px_--theme(--color-white/16%)] transition-all duration-150 hover:bg-destructive hover:scale-105 active:inset-shadow-[0_1px_--theme(--color-black/8%)] active:shadow-none",
-        insidePendingAction ? "size-8 sm:size-7" : "size-8 sm:h-8 sm:w-8",
+        insidePendingAction
+          ? "size-8 sm:size-7"
+          : showSendWhileRunning && hasSendableContent
+            ? "size-9 sm:size-8"
+            : "size-8 sm:h-8 sm:w-8",
       )}
       {...pointerFocusProps}
       onClick={onInterrupt}
@@ -153,10 +161,6 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
     );
   }
 
-  if (isRunning) {
-    return renderStopGenerationButton(false);
-  }
-
   if (showPlanFollowUpPrompt) {
     if (promptHasText) {
       return (
@@ -214,7 +218,7 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
     );
   }
 
-  return (
+  const sendButton = (
     <button
       type="submit"
       className={cn(
@@ -265,4 +269,15 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
       )}
     </button>
   );
+
+  if (!isRunning) {
+    return sendButton;
+  }
+
+  return (
+    <>
+      {renderStopGenerationButton(false)}
+      {showSendWhileRunning && hasSendableContent ? sendButton : null}
+    </>
+  );
 });