feat(chat): render A2UI surface theme chrome (agentDisplayName + iconUrl)

apps/website/content/docs/chat/a2ui/overview.mdx

@@ -194,7 +194,7 @@ Catalog components receive resolved props as Angular inputs from the render engi
 
 ## Theming
 
-`createSurface.theme` carries agent-supplied presentation hints. `primaryColor` flows to `<a2ui-surface>` as the `--a2ui-primary` CSS custom property, which catalog components consume for accents (buttons, sliders, focus rings). `iconUrl` and `agentDisplayName` identify the agent that owns the surface.
+`createSurface.theme` carries agent-supplied presentation hints. `primaryColor` flows to `<a2ui-surface>` as the `--a2ui-primary` CSS custom property, which catalog components consume for accents (buttons, sliders, focus rings). `iconUrl` and `agentDisplayName` identify the agent that owns the surface: when either is set, `<a2ui-surface>` renders a small identity header (a 16px round icon and the display name in muted label text) above the surface. Themeless surfaces render no header.
 
 ## Local Handlers
 

apps/website/content/docs/chat/a2ui/surface-component.mdx

@@ -61,7 +61,7 @@ When a component's `children` field is a template (`{ path, componentId }`), the
 
 The final `Spec` is passed to `RenderSpecComponent` along with the `ViewRegistry` (converted to an Angular registry via `toRenderRegistry`). Rendering is fully reactive — when the surface signal updates, the spec recomputes and only affected elements re-render.
 
-**Theming.** The component host applies the agent-set surface theme from `createSurface.theme`: `primaryColor` becomes the `--a2ui-primary` CSS custom property, which catalog components consume for accents. When the agent sets no theme, your `:root`-level `--a2ui-primary` default wins.
+**Theming.** The component host applies the agent-set surface theme from `createSurface.theme`: `primaryColor` becomes the `--a2ui-primary` CSS custom property, which catalog components consume for accents. When the agent sets no theme, your `:root`-level `--a2ui-primary` default wins. If the theme carries `agentDisplayName` and/or `iconUrl`, the component also renders a small identity header above the surface — a 16px round icon and the display name in muted label text. Surfaces without those fields render no header.
 
 ## Usage Outside ChatComponent
 

apps/website/content/docs/chat/api/api-docs.json

@@ -1088,6 +1088,12 @@
         "description": "",
         "optional": false
       },
+      {
+        "name": "agentDisplayName",
+        "type": "Signal<string | null>",
+        "description": "Agent identity chrome from `createSurface.theme`. When neither\n`agentDisplayName` nor `iconUrl` is set, no header renders at all\n(zero layout impact for themeless surfaces — the common case).",
+        "optional": false
+      },
       {
         "name": "catalog",
         "type": "InputSignal<Readonly<Record<string, Type<unknown> | RenderViewEntry>> | Readonly<Record<string, Type<unknown> | RenderViewEntry>>>",
@@ -1106,6 +1112,12 @@
         "description": "",
         "optional": false
       },
+      {
+        "name": "iconUrl",
+        "type": "Signal<string | null>",
+        "description": "",
+        "optional": false
+      },
       {
         "name": "internalHandlers",
         "type": "Signal<object>",

libs/chat/src/lib/a2ui/surface.component.spec.ts

@@ -196,6 +196,84 @@ describe('A2uiSurfaceComponent — validation gate + live context (Phase 3)', ()
   });
 });
 
+describe('A2uiSurfaceComponent — surface theme chrome', () => {
+  beforeEach(() => TestBed.configureTestingModule({ imports: [A2uiSurfaceComponent] }));
+
+  function makeThemedState(theme?: Record<string, unknown>) {
+    const store = createA2uiSurfaceStore();
+    store.apply({ version: 'v0.9', createSurface: {
+      surfaceId: 's1', catalogId: 'basic', ...(theme ? { theme } : {}),
+    } } as never);
+    store.apply({ version: 'v0.9', updateComponents: {
+      surfaceId: 's1',
+      components: [{ id: 'root', component: 'Text', text: 'Hello' }],
+    } } as never);
+    return store.surfaceState('s1')()!;
+  }
+
+  it('renders agentDisplayName and iconUrl as a header above the surface', () => {
+    const fx = TestBed.createComponent(A2uiSurfaceComponent);
+    fx.componentRef.setInput('state', makeThemedState({
+      agentDisplayName: 'Flight Bot', iconUrl: 'https://x/icon.png',
+    }));
+    fx.componentRef.setInput('catalog', a2uiBasicCatalog());
+    fx.detectChanges();
+
+    const chrome = fx.nativeElement.querySelector('.a2ui-surface-chrome');
+    expect(chrome).toBeTruthy();
+    expect(chrome.textContent).toContain('Flight Bot');
+    const img = chrome.querySelector('img');
+    expect(img).toBeTruthy();
+    expect(img.getAttribute('src')).toBe('https://x/icon.png');
+    expect(img.getAttribute('referrerpolicy')).toBe('no-referrer');
+    expect(img.getAttribute('alt')).toBe('');
+  });
+
+  it('renders the name alone when only agentDisplayName is set', () => {
+    const fx = TestBed.createComponent(A2uiSurfaceComponent);
+    fx.componentRef.setInput('state', makeThemedState({ agentDisplayName: 'Flight Bot' }));
+    fx.componentRef.setInput('catalog', a2uiBasicCatalog());
+    fx.detectChanges();
+
+    const chrome = fx.nativeElement.querySelector('.a2ui-surface-chrome');
+    expect(chrome).toBeTruthy();
+    expect(chrome.textContent).toContain('Flight Bot');
+    expect(chrome.querySelector('img')).toBeNull();
+  });
+
+  it('renders no chrome element at all for a themeless surface', () => {
+    const fx = TestBed.createComponent(A2uiSurfaceComponent);
+    fx.componentRef.setInput('state', makeThemedState());
+    fx.componentRef.setInput('catalog', a2uiBasicCatalog());
+    fx.detectChanges();
+
+    expect(fx.nativeElement.querySelector('.a2ui-surface-chrome')).toBeNull();
+    // The surface itself still renders.
+    expect(fx.nativeElement.textContent).toContain('Hello');
+  });
+
+  it('renders no chrome when the theme only carries primaryColor', () => {
+    const fx = TestBed.createComponent(A2uiSurfaceComponent);
+    fx.componentRef.setInput('state', makeThemedState({ primaryColor: '#ff0066' }));
+    fx.componentRef.setInput('catalog', a2uiBasicCatalog());
+    fx.detectChanges();
+
+    expect(fx.nativeElement.querySelector('.a2ui-surface-chrome')).toBeNull();
+  });
+
+  it('still applies primaryColor as the --a2ui-primary host style', () => {
+    const fx = TestBed.createComponent(A2uiSurfaceComponent);
+    fx.componentRef.setInput('state', makeThemedState({
+      primaryColor: '#ff0066', agentDisplayName: 'Flight Bot',
+    }));
+    fx.componentRef.setInput('catalog', a2uiBasicCatalog());
+    fx.detectChanges();
+
+    expect(fx.nativeElement.style.getPropertyValue('--a2ui-primary')).toBe('#ff0066');
+    expect(fx.nativeElement.querySelector('.a2ui-surface-chrome')).toBeTruthy();
+  });
+});
+
 describe('A2uiSurfaceComponent — sendDataModel live round-trip (Phase 4)', () => {
   beforeEach(() => TestBed.configureTestingModule({ imports: [A2uiSurfaceComponent] }));
 

libs/chat/src/lib/a2ui/surface.component.ts

@@ -30,7 +30,33 @@ import type { A2uiViews } from './views';
   host: {
     '[style.--a2ui-primary]': 'primaryColor()',
   },
+  styles: `
+    .a2ui-surface-chrome {
+      display: flex;
+      align-items: center;
+      gap: var(--a2ui-spacing-2);
+      margin-bottom: var(--a2ui-spacing-2);
+      color: var(--a2ui-label);
+      font-size: var(--a2ui-typography-label-size);
+    }
+    .a2ui-surface-chrome img {
+      width: 16px;
+      height: 16px;
+      border-radius: 50%;
+      object-fit: cover;
+    }
+  `,
   template: `
+    @if (agentDisplayName() || iconUrl()) {
+      <div class="a2ui-surface-chrome">
+        @if (iconUrl(); as icon) {
+          <img [src]="icon" alt="" referrerpolicy="no-referrer" />
+        }
+        @if (agentDisplayName(); as name) {
+          <span>{{ name }}</span>
+        }
+      </div>
+    }
     @if (spec(); as s) {
       <render-spec
         [spec]="s"
@@ -115,6 +141,16 @@ export class A2uiSurfaceComponent {
     (this.state()?.surface ?? this.surface())?.theme?.primaryColor ?? null
   );
 
+  /** Agent identity chrome from `createSurface.theme`. When neither
+   * `agentDisplayName` nor `iconUrl` is set, no header renders at all
+   * (zero layout impact for themeless surfaces — the common case). */
+  protected readonly agentDisplayName = computed<string | null>(() =>
+    (this.state()?.surface ?? this.surface())?.theme?.agentDisplayName ?? null
+  );
+  protected readonly iconUrl = computed<string | null>(() =>
+    (this.state()?.surface ?? this.surface())?.theme?.iconUrl ?? null
+  );
+
   /** Roots from the surface state. The v0.9 wire contract reserves the
    * component id `root` as the single tree root; we keep the renderer
    * permissive in case future surfaces emit multiple top-level