diff --git a/ui/src/pages/AppsTab/AppDeploymentPage/AppDeploymentPage.module.css b/ui/src/pages/AppsTab/AppDeploymentPage/AppDeploymentPage.module.css
index 707d3418..0726b183 100644
--- a/ui/src/pages/AppsTab/AppDeploymentPage/AppDeploymentPage.module.css
+++ b/ui/src/pages/AppsTab/AppDeploymentPage/AppDeploymentPage.module.css
@@ -374,3 +374,29 @@
   background: var(--bg-inset);
   color: var(--text-primary);
 }
+
+/* Primary-button upload progress overlay
+ * Wraps the DS Button so the inner Button can retain its own background
+ * while we overlay a tinted progress fill and label on top. */
+.uploadBtnWrap {
+  display: inline-block;
+}
+
+.uploadBtnWrap button {
+  position: relative;
+  overflow: hidden;
+}
+
+.uploadBtnFill {
+  position: absolute;
+  inset: 0 auto 0 0;
+  background: color-mix(in srgb, var(--primary) 35%, transparent);
+  transition: width 120ms linear;
+  pointer-events: none;
+  z-index: 0;
+}
+
+.uploadBtnLabel {
+  position: relative;
+  z-index: 1;
+}
diff --git a/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.test.tsx b/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.test.tsx
new file mode 100644
index 00000000..192f1af3
--- /dev/null
+++ b/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.test.tsx
@@ -0,0 +1,55 @@
+import type { ReactElement } from 'react';
+import { describe, it, expect } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import { ThemeProvider } from '@cameleer/design-system';
+import { PrimaryActionButton, computeMode } from './PrimaryActionButton';
+
+function wrap(ui: ReactElement) {
+  return render(<ThemeProvider>{ui}</ThemeProvider>);
+}
+
+describe('PrimaryActionButton', () => {
+  it('renders Save in save mode', () => {
+    wrap(<PrimaryActionButton mode="save" enabled onClick={() => {}} />);
+    expect(screen.getByRole('button', { name: /save/i })).toBeInTheDocument();
+  });
+
+  it('renders Redeploy in redeploy mode', () => {
+    wrap(<PrimaryActionButton mode="redeploy" enabled onClick={() => {}} />);
+    expect(screen.getByRole('button', { name: /redeploy/i })).toBeInTheDocument();
+  });
+
+  it('renders Deploying… disabled in deploying mode', () => {
+    wrap(<PrimaryActionButton mode="deploying" enabled={false} onClick={() => {}} />);
+    const btn = screen.getByRole('button', { name: /deploying/i });
+    expect(btn).toBeDisabled();
+  });
+
+  it('renders Uploading… NN% with progress overlay in uploading mode', () => {
+    wrap(<PrimaryActionButton mode="uploading" enabled={false} progress={42} onClick={() => {}} />);
+    const btn = screen.getByRole('button', { name: /uploading/i });
+    expect(btn).toBeDisabled();
+    expect(btn).toHaveTextContent('42%');
+    const fill = btn.querySelector('[data-upload-fill]') as HTMLElement | null;
+    expect(fill).not.toBeNull();
+    expect(fill!.style.width).toBe('42%');
+  });
+});
+
+describe('computeMode', () => {
+  it('returns uploading when uploading flag set, even if deploymentInProgress is false', () => {
+    expect(computeMode({ deploymentInProgress: false, uploading: true, hasLocalEdits: true, serverDirtyAgainstDeploy: false })).toBe('uploading');
+  });
+
+  it('returns deploying when deploymentInProgress even if uploading flag set', () => {
+    expect(computeMode({ deploymentInProgress: true, uploading: true, hasLocalEdits: false, serverDirtyAgainstDeploy: false })).toBe('deploying');
+  });
+
+  it('returns save when local edits without upload or deploy', () => {
+    expect(computeMode({ deploymentInProgress: false, uploading: false, hasLocalEdits: true, serverDirtyAgainstDeploy: false })).toBe('save');
+  });
+
+  it('returns redeploy when server dirty and no local edits', () => {
+    expect(computeMode({ deploymentInProgress: false, uploading: false, hasLocalEdits: false, serverDirtyAgainstDeploy: true })).toBe('redeploy');
+  });
+});
diff --git a/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.tsx b/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.tsx
index ef4e9ac7..c563a3aa 100644
--- a/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.tsx
+++ b/ui/src/pages/AppsTab/AppDeploymentPage/PrimaryActionButton.tsx
@@ -1,14 +1,32 @@
 import { Button } from '@cameleer/design-system';
+import styles from './AppDeploymentPage.module.css';
 
-export type PrimaryActionMode = 'save' | 'redeploy' | 'deploying';
+export type PrimaryActionMode = 'save' | 'redeploy' | 'uploading' | 'deploying';
 
 interface Props {
   mode: PrimaryActionMode;
   enabled: boolean;
   onClick: () => void;
+  /** Upload percentage 0–100. Only meaningful when mode === 'uploading'. */
+  progress?: number;
 }
 
-export function PrimaryActionButton({ mode, enabled, onClick }: Props) {
+export function PrimaryActionButton({ mode, enabled, onClick, progress }: Props) {
+  if (mode === 'uploading') {
+    const pct = Math.max(0, Math.min(100, Math.round(progress ?? 0)));
+    return (
+      <span className={styles.uploadBtnWrap}>
+        <Button size="sm" variant="primary" disabled>
+          <span
+            data-upload-fill
+            className={styles.uploadBtnFill}
+            style={{ width: `${pct}%` }}
+          />
+          <span className={styles.uploadBtnLabel}>Uploading… {pct}%</span>
+        </Button>
+      </span>
+    );
+  }
   if (mode === 'deploying') {
     return <Button size="sm" variant="primary" loading disabled>Deploying…</Button>;
   }
@@ -20,14 +38,17 @@ export function PrimaryActionButton({ mode, enabled, onClick }: Props) {
 
 export function computeMode({
   deploymentInProgress,
+  uploading,
   hasLocalEdits,
   serverDirtyAgainstDeploy,
 }: {
   deploymentInProgress: boolean;
+  uploading: boolean;
   hasLocalEdits: boolean;
   serverDirtyAgainstDeploy: boolean;
 }): PrimaryActionMode {
   if (deploymentInProgress) return 'deploying';
+  if (uploading) return 'uploading';
   if (hasLocalEdits) return 'save';
   if (serverDirtyAgainstDeploy) return 'redeploy';
   return 'save';