diff --git a/docs/web/workspaces.md b/docs/web/workspaces.md
index 57f1e4e1b145..1cfcaa372957 100644
--- a/docs/web/workspaces.md
+++ b/docs/web/workspaces.md
@@ -65,6 +65,11 @@ lists only pending entries from the Workspaces custom-widget registry. Its Appro
 Reject controls are disabled unless the current connection holds `operator.approvals`;
 it does not expose exec, plugin, or system-agent approvals.
 
+Tabs use the 12-column widget grid by default. A tab containing zero or one widget can
+instead use the `full` layout, which removes the widget card chrome and lets the widget
+fill the tab. Switch layouts with `openclaw workspaces tabs full <slug>` and
+`openclaw workspaces tabs grid <slug>`.
+
 Widgets declare data through **bindings**, they never fetch on their own:
 
 | Binding  | Resolves to                                                                                               |
@@ -110,6 +115,7 @@ per-invocation confirmation quoting the exact text, and passes a rate limit.
 ```sh
 openclaw workspaces tabs list
 openclaw workspaces tabs create --title Financials
+openclaw workspaces tabs full financials
 openclaw workspaces widget-scaffold revenue-chart --title "Revenue Chart"
 openclaw workspaces widget-approve revenue-chart
 ```
diff --git a/extensions/workspaces/src/cli.ts b/extensions/workspaces/src/cli.ts
index c11fb256c997..c9b6cce5abd3 100644
--- a/extensions/workspaces/src/cli.ts
+++ b/extensions/workspaces/src/cli.ts
@@ -287,6 +287,21 @@ export function registerWorkspaceCli(options: RegisterWorkspaceCliOptions): void
     });
   }
 
+  for (const [verb, tabLayout] of [
+    ["grid", "grid"],
+    ["full", "full"],
+  ] as const) {
+    addGatewayOptions(
+      tabs.command(verb).argument("<slug>", "Tab slug").description(`Use ${tabLayout} layout`),
+    ).action(async (slug: string, commandOptions: GatewayOptions) => {
+      const result = await callWorkspaceGateway("workspaces.tab.update", commandOptions, {
+        slug,
+        patch: { layout: tabLayout },
+      });
+      writeTabs(readWorkspaceResult(result).doc, commandOptions);
+    });
+  }
+
   addGatewayOptions(
     widgets
       .command("list")
diff --git a/extensions/workspaces/src/gateway.ts b/extensions/workspaces/src/gateway.ts
index 032f0c5784bf..0affa054f25e 100644
--- a/extensions/workspaces/src/gateway.ts
+++ b/extensions/workspaces/src/gateway.ts
@@ -276,8 +276,10 @@ function readRequiredBoolean(record: Record<string, unknown>, key: string): bool
   return value;
 }
 
-function readTabPatch(value: unknown): Partial<Pick<WorkspaceTab, "title" | "icon" | "hidden">> {
-  const patch = readParams(value, ["title", "icon", "hidden"]);
+function readTabPatch(
+  value: unknown,
+): Partial<Pick<WorkspaceTab, "title" | "icon" | "hidden" | "layout">> {
+  const patch = readParams(value, ["title", "icon", "hidden", "layout"]);
   const title = readOptionalString(patch, "title");
   if (title !== undefined && (title.length < 1 || title.length > 80)) {
     throw new Error("patch.title must be 1-80 characters");
@@ -287,10 +289,15 @@ function readTabPatch(value: unknown): Partial<Pick<WorkspaceTab, "title" | "ico
     throw new Error("patch.icon must be 40 characters or fewer");
   }
   const hidden = readBooleanPatch(patch, "hidden");
+  const layout = patch.layout;
+  if (layout !== undefined && layout !== "grid" && layout !== "full") {
+    throw new Error('patch.layout must be "grid" or "full"');
+  }
   return {
     ...(title !== undefined ? { title } : {}),
     ...(icon !== undefined ? { icon } : {}),
     ...(hidden !== undefined ? { hidden } : {}),
+    ...(layout !== undefined ? { layout } : {}),
   };
 }
 
diff --git a/extensions/workspaces/src/schema.test.ts b/extensions/workspaces/src/schema.test.ts
index 766829064658..0b103b063218 100644
--- a/extensions/workspaces/src/schema.test.ts
+++ b/extensions/workspaces/src/schema.test.ts
@@ -24,6 +24,24 @@ describe("Workspaces document schema", () => {
     expect(validateWorkspaceDoc(doc).tabs[0]!.widgets[0]!.kind).toBe(kind);
   });
 
+  it("accepts full-bleed tabs and rejects unknown layouts", () => {
+    const doc = validDoc();
+    doc.tabs[0]!.widgets = doc.tabs[0]!.widgets.slice(0, 1);
+    doc.tabs[0]!.layout = "full";
+    expect(validateWorkspaceDoc(doc).tabs[0]?.layout).toBe("full");
+    expectInvalid((invalid) => {
+      invalid.tabs[0]!.layout = "columns" as never;
+    }, 'layout must be "grid" or "full"');
+
+    expectInvalid((invalid) => {
+      invalid.tabs[0]!.layout = "full";
+      invalid.tabs[0]!.widgets.push({
+        ...structuredClone(invalid.tabs[0]!.widgets[0]!),
+        id: "second",
+      });
+    }, "at most one entry for full layout");
+  });
+
   it("rejects invalid tab slugs", () => {
     expectInvalid((doc) => {
       doc.tabs[0]!.slug = "Bad Slug";
diff --git a/extensions/workspaces/src/schema.ts b/extensions/workspaces/src/schema.ts
index a454e29de7a5..899349431308 100644
--- a/extensions/workspaces/src/schema.ts
+++ b/extensions/workspaces/src/schema.ts
@@ -35,6 +35,8 @@ export type WorkspaceTab = {
   title: string;
   icon?: string;
   hidden: boolean;
+  /** Default grid, or a single app-like widget without grid chrome. */
+  layout?: "grid" | "full";
   createdBy: WorkspaceActor;
   widgets: WorkspaceWidget[];
 };
@@ -299,7 +301,11 @@ function validateWidget(value: unknown, path: string): WorkspaceWidget {
 
 function validateTab(value: unknown, path: string): WorkspaceTab {
   const record = assertRecord(value, path);
-  assertKnownKeys(record, ["slug", "title", "icon", "hidden", "createdBy", "widgets"], path);
+  assertKnownKeys(
+    record,
+    ["slug", "title", "icon", "hidden", "layout", "createdBy", "widgets"],
+    path,
+  );
   const slug = requireString(record, "slug", path);
   if (!TAB_SLUG_PATTERN.test(slug)) {
     throw new Error(`${path}.slug is invalid`);
@@ -312,15 +318,23 @@ function validateTab(value: unknown, path: string): WorkspaceTab {
   if (icon !== undefined && icon.length > 40) {
     throw new Error(`${path}.icon must be 40 characters or fewer`);
   }
+  const layout = record.layout;
+  if (layout !== undefined && layout !== "grid" && layout !== "full") {
+    throw new Error(`${path}.layout must be "grid" or "full"`);
+  }
   const widgets = requireArray(record.widgets, `${path}.widgets`);
   if (widgets.length > 24) {
     throw new Error(`${path}.widgets must contain at most 24 entries`);
   }
+  if (layout === "full" && widgets.length > 1) {
+    throw new Error(`${path}.widgets must contain at most one entry for full layout`);
+  }
   return {
     slug,
     title,
     ...(icon !== undefined ? { icon } : {}),
     hidden: requireBoolean(record, "hidden", path),
+    ...(layout !== undefined ? { layout } : {}),
     createdBy: validateActor(record.createdBy, `${path}.createdBy`),
     widgets: widgets.map((widget, index) => validateWidget(widget, `${path}.widgets[${index}]`)),
   };
diff --git a/extensions/workspaces/src/tools.test.ts b/extensions/workspaces/src/tools.test.ts
index 80c2d97f740c..2a84c0c1c62a 100644
--- a/extensions/workspaces/src/tools.test.ts
+++ b/extensions/workspaces/src/tools.test.ts
@@ -91,7 +91,7 @@ describe("workspace tools", () => {
     const validSamples: Record<string, unknown> = {
       workspace_get: {},
       workspace_tab_create: { title: "Finance" },
-      workspace_tab_update: { slug: "main", hidden: true },
+      workspace_tab_update: { slug: "main", hidden: true, layout: "full" },
       workspace_tab_delete: { slug: "old" },
       workspace_tabs_reorder: { order: ["main"] },
       workspace_widget_add: {
diff --git a/extensions/workspaces/src/tools.ts b/extensions/workspaces/src/tools.ts
index 406157faef65..cfe59b67605c 100644
--- a/extensions/workspaces/src/tools.ts
+++ b/extensions/workspaces/src/tools.ts
@@ -539,22 +539,31 @@ export function createWorkspaceTools(params: WorkspaceToolParams): AnyAgentTool[
     {
       name: "workspace_tab_update",
       label: "Workspace Tab Update",
-      description: toolDescription("Update a workspace tab title, icon, or hidden state."),
+      description: toolDescription("Update a workspace tab title, icon, hidden state, or layout."),
       parameters: Type.Object(
         {
           slug: Type.String({ description: "Tab slug." }),
           title: Type.Optional(Type.String({ description: "New title." })),
           icon: Type.Optional(Type.String({ description: "New icon." })),
           hidden: Type.Optional(Type.Boolean({ description: "Hide or show the tab." })),
+          layout: Type.Optional(
+            Type.Union([Type.Literal("grid"), Type.Literal("full")], {
+              description: "Grid layout, or one full-bleed app widget.",
+            }),
+          ),
         },
         { additionalProperties: false },
       ),
       execute: async (_toolCallId, rawParams) => {
-        const record = readRecord(rawParams, ["slug", "title", "icon", "hidden"]);
+        const record = readRecord(rawParams, ["slug", "title", "icon", "hidden", "layout"]);
         const slug = readSlug(record);
         const title = readOptionalString(record, "title");
         const icon = readOptionalString(record, "icon");
         const hidden = readOptionalBoolean(record, "hidden");
+        const layout = record.layout;
+        if (layout !== undefined && layout !== "grid" && layout !== "full") {
+          throw new Error('layout must be "grid" or "full"');
+        }
         return await runMutation({
           ...mutationBase,
           changedTabSlug: slug,
@@ -563,6 +572,7 @@ export function createWorkspaceTools(params: WorkspaceToolParams): AnyAgentTool[
               ...(title !== undefined ? { title } : {}),
               ...(icon !== undefined ? { icon } : {}),
               ...(hidden !== undefined ? { hidden } : {}),
+              ...(layout !== undefined ? { layout } : {}),
             });
           },
         });
diff --git a/ui/src/components/workspace-custom-widget.ts b/ui/src/components/workspace-custom-widget.ts
index 287b3517e692..e1d0ac4c7a1e 100644
--- a/ui/src/components/workspace-custom-widget.ts
+++ b/ui/src/components/workspace-custom-widget.ts
@@ -324,7 +324,7 @@ class CustomWidgetFrameDirective extends AsyncDirective {
       return iframe;
     } catch (error) {
       // A directive's render runs at Lit COMMIT time, outside the try/catch in
-      // `renderWidgetBody`. A throw here would escape the per-cell error boundary
+      // `renderWorkspaceWidgetBody`. A throw here would escape the per-cell error boundary
       // and take down the whole tab, so the boundary has to exist here too.
       this.detach = null;
       this.iframe = null;
diff --git a/ui/src/components/workspace-widget-cell.ts b/ui/src/components/workspace-widget-cell.ts
index 7f156a27d67a..b40d346674fa 100644
--- a/ui/src/components/workspace-widget-cell.ts
+++ b/ui/src/components/workspace-widget-cell.ts
@@ -132,7 +132,7 @@ function renderBuiltinWidget(
     return renderer(widget, value, ctx);
   }
   if (widget.kind.startsWith("custom:")) {
-    // Custom widgets are dispatched by renderWidgetBody BEFORE this builtin path;
+    // Custom widgets are dispatched by renderWorkspaceWidgetBody BEFORE this builtin path;
     // reaching here means no L5 host context was supplied (e.g. a unit test
     // rendering the builtin body in isolation). Neutral placeholder — never an
     // iframe without a manifest.
@@ -219,7 +219,7 @@ function renderCustomWidget(
  * broken widget, a bad binding) is caught and rendered as an error card in THIS
  * cell — siblings and the shell keep rendering (spec-30 acceptance criterion).
  */
-function renderWidgetBody(
+export function renderWorkspaceWidgetBody(
   widget: WorkspaceWidget,
   binding: WorkspaceBindingResult | null,
   ctx: BuiltinWidgetContext,
@@ -346,7 +346,7 @@ export function renderWidgetCell(props: WorkspaceWidgetCellProps): TemplateResul
         ? nothing
         : html`
             <div class="workspace-widget__body">
-              ${renderWidgetBody(
+              ${renderWorkspaceWidgetBody(
                 widget,
                 props.binding,
                 props.builtinContext,
diff --git a/ui/src/e2e/workspace-full-bleed.e2e.test.ts b/ui/src/e2e/workspace-full-bleed.e2e.test.ts
new file mode 100644
index 000000000000..3319bd68a654
--- /dev/null
+++ b/ui/src/e2e/workspace-full-bleed.e2e.test.ts
@@ -0,0 +1,135 @@
+import { mkdir } from "node:fs/promises";
+import path from "node:path";
+import { chromium, type Browser, type Page } from "playwright";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+import {
+  canRunPlaywrightChromium,
+  installMockGateway,
+  resolvePlaywrightChromiumExecutablePath,
+  startControlUiE2eServer,
+  type ControlUiE2eServer,
+} from "../test-helpers/control-ui-e2e.ts";
+
+const chromiumExecutablePath = resolvePlaywrightChromiumExecutablePath(chromium.executablePath());
+const chromiumAvailable = canRunPlaywrightChromium(chromiumExecutablePath);
+const allowMissingChromium = process.env.OPENCLAW_UI_E2E_ALLOW_MISSING_CHROMIUM === "1";
+const describeControlUiE2e = chromiumAvailable || !allowMissingChromium ? describe : describe.skip;
+const proofDir = process.env.OPENCLAW_UI_E2E_ARTIFACT_DIR?.trim();
+const baselineOnly = process.env.OPENCLAW_UI_E2E_BASELINE === "1";
+
+let browser: Browser;
+let server: ControlUiE2eServer;
+
+function workspaceDoc() {
+  return {
+    doc: {
+      schemaVersion: 1,
+      workspaceVersion: 1,
+      tabs: [
+        {
+          slug: "release-room",
+          title: "Release room",
+          hidden: false,
+          layout: baselineOnly ? "grid" : "full",
+          createdBy: "agent:main",
+          widgets: [
+            {
+              id: "release_room_app",
+              kind: "builtin:iframe-embed",
+              title: "Release room app",
+              grid: { x: 2, y: 0, w: 8, h: 6 },
+              collapsed: false,
+              createdBy: "agent:main",
+              props: { url: "/full-bleed-proof" },
+            },
+          ],
+        },
+      ],
+      widgetsRegistry: {},
+      prefs: { tabOrder: ["release-room"] },
+    },
+    workspaceVersion: 1,
+  };
+}
+
+async function capture(page: Page, name: string): Promise<void> {
+  if (!proofDir) {
+    return;
+  }
+  await mkdir(proofDir, { recursive: true });
+  await page.screenshot({ fullPage: true, path: path.join(proofDir, name) });
+}
+
+describeControlUiE2e("Control UI full-bleed workspace tabs", () => {
+  beforeAll(async () => {
+    if (!chromiumAvailable) {
+      throw new Error(`Playwright Chromium is not available at ${chromiumExecutablePath}`);
+    }
+    server = await startControlUiE2eServer();
+    browser = await chromium.launch({ executablePath: chromiumExecutablePath });
+  });
+
+  afterAll(async () => {
+    await browser?.close();
+    await server?.close();
+  });
+
+  it("removes grid chrome and lets the single sandboxed app fill the tab", async () => {
+    const context = await browser.newContext({
+      locale: "en-US",
+      serviceWorkers: "block",
+      viewport: { height: 900, width: 1440 },
+    });
+    const page = await context.newPage();
+    await page.route("**/full-bleed-proof", (route) =>
+      route.fulfill({
+        contentType: "text/html",
+        body: `<!doctype html><style>
+          body { margin: 0; min-height: 100vh; display: grid; place-items: center; background: #071a2b; color: #e8f4ff; font: 18px system-ui; }
+          main { width: min(760px, 80%); padding: 48px; border: 1px solid #3278a8; border-radius: 18px; background: #0d2942; }
+          h1 { margin-top: 0; color: #62d9ff; } .status { color: #8ce99a; }
+        </style><main><p class="status">All systems ready</p><h1>Release room</h1><p>One app. The whole workspace tab.</p></main>`,
+      }),
+    );
+    await installMockGateway(page, {
+      controlUiTabs: [
+        { pluginId: "workspaces", id: "workspaces", label: "Workspaces", group: "control" },
+      ],
+      featureMethods: ["workspaces.get"],
+      methodResponses: { "workspaces.get": workspaceDoc() },
+    });
+
+    try {
+      const response = await page.goto(`${server.baseUrl}plugin?plugin=workspaces&id=workspaces`);
+      expect(response?.status()).toBe(200);
+      await page.locator('[data-test-id="workspace-onboarding-dismiss"]').click();
+      const frame = page.locator('[data-test-id="workspace-embed-frame"]');
+      await frame.waitFor({ timeout: 10_000 });
+      expect(await frame.getAttribute("sandbox")).toBe("allow-scripts");
+
+      if (baselineOnly) {
+        expect(await page.locator('[data-test-id="workspace-grid"]').count()).toBe(1);
+        expect(await page.locator('[data-test-id="workspace-widget"]').count()).toBe(1);
+        await capture(page, "workspace-full-bleed-before.png");
+        return;
+      }
+
+      const fullBleed = page.locator('[data-test-id="workspace-fullbleed"]');
+      await fullBleed.waitFor();
+      expect(await page.locator('[data-test-id="workspace-grid"]').count()).toBe(0);
+      expect(await page.locator('[data-test-id="workspace-widget"]').count()).toBe(0);
+      const [containerBox, frameBox] = await Promise.all([
+        fullBleed.boundingBox(),
+        frame.boundingBox(),
+      ]);
+      expect(containerBox).not.toBeNull();
+      expect(frameBox).not.toBeNull();
+      expect(Math.abs(frameBox!.width - containerBox!.width)).toBeLessThan(2);
+      expect(Math.abs(frameBox!.height - containerBox!.height)).toBeLessThan(2);
+      expect(frameBox!.height).toBeGreaterThanOrEqual(480);
+      await capture(page, "workspace-full-bleed-after.png");
+    } finally {
+      await context.close();
+    }
+  });
+});
diff --git a/ui/src/lib/workspace/index.ts b/ui/src/lib/workspace/index.ts
index 07b019a6216b..295e7fd4f4a7 100644
--- a/ui/src/lib/workspace/index.ts
+++ b/ui/src/lib/workspace/index.ts
@@ -221,6 +221,7 @@ function normalizeTab(value: unknown): WorkspaceTab | null {
     title: readString(value.title, slug),
     hidden: value.hidden === true,
     widgets,
+    ...(value.layout === "grid" || value.layout === "full" ? { layout: value.layout } : {}),
     ...(typeof value.icon === "string" ? { icon: value.icon } : {}),
     ...(typeof value.createdBy === "string" ? { createdBy: value.createdBy } : {}),
   };
diff --git a/ui/src/lib/workspace/types.ts b/ui/src/lib/workspace/types.ts
index 1e3c0f520814..40ceb8c7b43c 100644
--- a/ui/src/lib/workspace/types.ts
+++ b/ui/src/lib/workspace/types.ts
@@ -12,6 +12,7 @@ export const WORKSPACE_GRID_COLUMNS = 12;
 export type WorkspaceCreatedBy = string;
 
 type WorkspaceWidgetKind = string;
+type WorkspaceTabLayout = "grid" | "full";
 
 type WorkspaceBindingSource = "rpc" | "file" | "static";
 
@@ -51,6 +52,7 @@ export type WorkspaceTab = {
   title: string;
   icon?: string;
   hidden: boolean;
+  layout?: WorkspaceTabLayout;
   createdBy?: WorkspaceCreatedBy;
   widgets: WorkspaceWidget[];
 };
diff --git a/ui/src/pages/plugin/workspace-view.test.ts b/ui/src/pages/plugin/workspace-view.test.ts
index bb01ab3a81bb..1f91508d4898 100644
--- a/ui/src/pages/plugin/workspace-view.test.ts
+++ b/ui/src/pages/plugin/workspace-view.test.ts
@@ -90,6 +90,19 @@ describe("renderWorkspace", () => {
     expect(container.querySelector('[data-test-id="workspace-empty-tab"]')).not.toBeNull();
   });
 
+  it("renders the first widget full bleed without grid chrome", () => {
+    const host = {};
+    const state = getWorkspaceState(host);
+    state.loaded = true;
+    state.workspace = structuredClone(doc);
+    state.workspace.tabs[0]!.layout = "full";
+    state.activeSlug = "main";
+    const container = renderView(host);
+    expect(container.querySelector('[data-test-id="workspace-fullbleed"]')).not.toBeNull();
+    expect(container.querySelector('[data-test-id="workspace-grid"]')).toBeNull();
+    expect(container.textContent).toContain("hello");
+  });
+
   it("surfaces an action error toast", () => {
     const host = {};
     const state = getWorkspaceState(host);
diff --git a/ui/src/pages/plugin/workspace-view.ts b/ui/src/pages/plugin/workspace-view.ts
index 83332cedf8ff..e4addbe7eaeb 100644
--- a/ui/src/pages/plugin/workspace-view.ts
+++ b/ui/src/pages/plugin/workspace-view.ts
@@ -13,6 +13,7 @@ import {
   type CustomWidgetHostContext,
 } from "../../components/workspace-custom-widget.ts";
 import {
+  renderWorkspaceWidgetBody,
   renderWidgetCell,
   type WorkspaceCustomWidgetContext,
   type WorkspaceWidgetCellCallbacks,
@@ -551,6 +552,36 @@ function buildCustomContext(
   };
 }
 
+/** Shared ambient builtin state; full-bleed tabs must preserve every grid capability. */
+function buildBuiltinContext(
+  props: WorkspaceProps,
+  state: WorkspaceUiState,
+  viewState: WorkspaceViewState,
+  workspace: WorkspaceDocument,
+): BuiltinWidgetContext {
+  const decideCustomWidget = props.canApproveWidgets
+    ? (name: string, decision: "approved" | "rejected") => {
+        void approveWidget(state, props.client, { name, decision });
+      }
+    : undefined;
+  return {
+    basePath: props.basePath ?? "",
+    embed: props.embed ?? DEFAULT_EMBED_CONTEXT,
+    preview: {
+      getViewport: (widgetId, fallback) => viewState.previewViewports.get(widgetId) ?? fallback,
+      setViewport: (widgetId, viewport) => {
+        viewState.previewViewports.set(widgetId, viewport);
+        props.onRequestUpdate?.();
+      },
+    },
+    customWidgetApprovals: buildCustomWidgetApprovalsSource(
+      workspace,
+      state.pendingApprovalNames,
+      decideCustomWidget,
+    ),
+  };
+}
+
 function renderGrid(
   props: WorkspaceProps,
   state: WorkspaceUiState,
@@ -571,28 +602,11 @@ function renderGrid(
       </div>
     `;
   }
+  if (tab.layout === "full") {
+    return renderFullBleed(props, state, viewState, workspace, tab);
+  }
   const callbacks = makeCallbacks(props, state, viewState, tab);
-  const decideCustomWidget = props.canApproveWidgets
-    ? (name: string, decision: "approved" | "rejected") => {
-        void approveWidget(state, props.client, { name, decision });
-      }
-    : undefined;
-  const builtinContext: BuiltinWidgetContext = {
-    basePath: props.basePath ?? "",
-    embed: props.embed ?? DEFAULT_EMBED_CONTEXT,
-    preview: {
-      getViewport: (widgetId, fallback) => viewState.previewViewports.get(widgetId) ?? fallback,
-      setViewport: (widgetId, viewport) => {
-        viewState.previewViewports.set(widgetId, viewport);
-        props.onRequestUpdate?.();
-      },
-    },
-    customWidgetApprovals: buildCustomWidgetApprovalsSource(
-      workspace,
-      state.pendingApprovalNames,
-      decideCustomWidget,
-    ),
-  };
+  const builtinContext = buildBuiltinContext(props, state, viewState, workspace);
   const rows = gridRowCount(tab.widgets);
   const minHeight = rows * WORKSPACE_ROW_HEIGHT + Math.max(0, rows - 1) * WORKSPACE_GRID_GAP;
   return html`
@@ -615,6 +629,33 @@ function renderGrid(
   `;
 }
 
+/** App-like tabs render their first widget through the same approval and sandbox path. */
+function renderFullBleed(
+  props: WorkspaceProps,
+  state: WorkspaceUiState,
+  viewState: WorkspaceViewState,
+  workspace: WorkspaceDocument,
+  tab: WorkspaceTab,
+): TemplateResult {
+  const widget = tab.widgets[0]!;
+  const callbacks = makeCallbacks(props, state, viewState, tab);
+  const builtinContext = buildBuiltinContext(props, state, viewState, workspace);
+  const custom = buildCustomContext(props, state, viewState, workspace, widget);
+  return html`<div
+    class="workspace-fullbleed"
+    data-test-id="workspace-fullbleed"
+    data-widget-id=${widget.id}
+  >
+    ${renderWorkspaceWidgetBody(
+      widget,
+      viewState.bindingResults.get(widget.id) ?? null,
+      builtinContext,
+      callbacks,
+      custom ?? undefined,
+    )}
+  </div>`;
+}
+
 /**
  * Snapped drop-target ghost for the active move/resize drag (#4). Placed in the
  * same grid slot the drop would land in so the target is obvious. An overlapping
diff --git a/ui/src/styles/workspace.css b/ui/src/styles/workspace.css
index 511b60b47d68..a7ddfd893f42 100644
--- a/ui/src/styles/workspace.css
+++ b/ui/src/styles/workspace.css
@@ -129,6 +129,20 @@ button.workspace-tab:hover {
   min-height: 0;
 }
 
+.workspace-fullbleed {
+  flex: 1;
+  min-width: 0;
+  min-height: 0;
+  overflow: auto;
+}
+
+.workspace-fullbleed > .workspace-widget__custom,
+.workspace-fullbleed > .workspace-embed__frame {
+  width: 100%;
+  height: 100%;
+  min-height: 480px;
+}
+
 /* --- Widget cell --------------------------------------------------------- */
 
 .workspace-widget {
@@ -742,6 +756,7 @@ button.workspace-tab:hover {
 
 /* iframe-embed widget. */
 .workspace-embed__frame {
+  display: block;
   width: 100%;
   height: 100%;
   min-height: 120px;