feat(display): add desktop workspace creation flow

canvas/src/components/CreateWorkspaceDialog.tsx

@@ -33,6 +33,8 @@ interface HermesProvider {
   models: string[];
 }
 
+const DEFAULT_CREATE_MODEL = "anthropic:claude-opus-4-7";
+
 // All providers supported by Hermes runtime via providers.resolve_provider().
 // `defaultModel` is the slug injected into the workspace provision request
 // when the user picks this provider — template-hermes's derive-provider.sh
@@ -68,6 +70,10 @@ export function CreateWorkspaceButton() {
   const [creating, setCreating] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [workspaces, setWorkspaces] = useState<WorkspaceOption[]>([]);
+  const [displayEnabled, setDisplayEnabled] = useState(false);
+  const [displayInstanceType, setDisplayInstanceType] = useState("t3.xlarge");
+  const [displayRootGB, setDisplayRootGB] = useState("80");
+  const [displayResolution, setDisplayResolution] = useState("1920x1080");
   // Templates fetched from /api/templates — drives the dynamic provider
   // filter below. Same data source ConfigTab uses (PR #2454). When the
   // selected template declares `runtime_config.providers` in its
@@ -223,6 +229,10 @@ export function CreateWorkspaceButton() {
     setParentId("");
     setBudgetLimit("");
     setError(null);
+    setDisplayEnabled(false);
+    setDisplayInstanceType("t3.xlarge");
+    setDisplayRootGB("80");
+    setDisplayResolution("1920x1080");
     setHermesProvider("anthropic");
     setExternalRuntime("external");
     setHermesApiKey("");
@@ -264,6 +274,8 @@ export function CreateWorkspaceButton() {
       const parsedBudget = budgetLimit.trim()
         ? parseFloat(budgetLimit)
         : null;
+      const [displayWidth, displayHeight] = displayResolution.split("x").map((v) => parseInt(v, 10));
+      const parsedRootGB = parseInt(displayRootGB, 10);
 
       const createResp = await api.post<{
         id: string;
@@ -280,6 +292,21 @@ export function CreateWorkspaceButton() {
         tier,
         parent_id: parentId || undefined,
         budget_limit: parsedBudget,
+        ...(!isExternal && !isHermes ? { model: DEFAULT_CREATE_MODEL } : {}),
+        ...(displayEnabled
+          ? {
+              compute: {
+                instance_type: displayInstanceType,
+                volume: { root_gb: Number.isFinite(parsedRootGB) ? parsedRootGB : 80 },
+                display: {
+                  mode: "desktop-control",
+                  protocol: "novnc",
+                  width: Number.isFinite(displayWidth) ? displayWidth : 1920,
+                  height: Number.isFinite(displayHeight) ? displayHeight : 1080,
+                },
+              },
+            }
+          : {}),
         canvas: { x: Math.random() * 400 + 100, y: Math.random() * 300 + 100 },
         // Runtime=external flips the backend into awaiting-agent mode:
         // no container provisioning, token minted, connection payload
@@ -447,6 +474,73 @@ export function CreateWorkspaceButton() {
               </div>
             </div>
 
+            {!isExternal && (
+              <div className="rounded-lg border border-line/50 bg-surface-card/40 p-3">
+                <div className="mb-2 text-[11px] font-medium text-ink-mid">
+                  Container Config
+                </div>
+                <label className="flex items-center justify-between gap-3">
+                  <span className="text-xs font-medium text-ink">Display</span>
+                  <input
+                    type="checkbox"
+                    checked={displayEnabled}
+                    onChange={(e) => setDisplayEnabled(e.target.checked)}
+                    aria-label="Enable display"
+                    className="h-4 w-4"
+                  />
+                </label>
+                {displayEnabled && (
+                  <div className="mt-3 grid grid-cols-2 gap-2">
+                    <div>
+                      <label htmlFor="display-instance-type" className="mb-1 block text-[11px] text-ink-mid">
+                        Instance
+                      </label>
+                      <select
+                        id="display-instance-type"
+                        value={displayInstanceType}
+                        onChange={(e) => setDisplayInstanceType(e.target.value)}
+                        className="w-full bg-surface-card/60 border border-line/50 rounded-lg px-2 py-2 text-xs text-ink focus:outline-none focus:border-accent/60 focus:ring-1 focus:ring-accent/20 transition-colors"
+                      >
+                        <option value="t3.large">t3.large</option>
+                        <option value="t3.xlarge">t3.xlarge</option>
+                        <option value="m6i.xlarge">m6i.xlarge</option>
+                        <option value="c6i.xlarge">c6i.xlarge</option>
+                      </select>
+                    </div>
+                    <div>
+                      <label htmlFor="display-root-gb" className="mb-1 block text-[11px] text-ink-mid">
+                        Disk GB
+                      </label>
+                      <input
+                        id="display-root-gb"
+                        type="number"
+                        min="30"
+                        max="500"
+                        value={displayRootGB}
+                        onChange={(e) => setDisplayRootGB(e.target.value)}
+                        className="w-full bg-surface-card/60 border border-line/50 rounded-lg px-2 py-2 text-xs text-ink focus:outline-none focus:border-accent/60 focus:ring-1 focus:ring-accent/20 transition-colors"
+                      />
+                    </div>
+                    <div className="col-span-2">
+                      <label htmlFor="display-resolution" className="mb-1 block text-[11px] text-ink-mid">
+                        Resolution
+                      </label>
+                      <select
+                        id="display-resolution"
+                        value={displayResolution}
+                        onChange={(e) => setDisplayResolution(e.target.value)}
+                        className="w-full bg-surface-card/60 border border-line/50 rounded-lg px-2 py-2 text-xs text-ink focus:outline-none focus:border-accent/60 focus:ring-1 focus:ring-accent/20 transition-colors"
+                      >
+                        <option value="1920x1080">1920 x 1080</option>
+                        <option value="1600x900">1600 x 900</option>
+                        <option value="1280x720">1280 x 720</option>
+                      </select>
+                    </div>
+                  </div>
+                )}
+              </div>
+            )}
+
             <div>
               <label className="text-[11px] text-ink-mid block mb-1">
                 Parent Workspace

canvas/src/components/__tests__/CreateWorkspaceDialog.test.tsx

@@ -123,6 +123,46 @@ describe("CreateWorkspaceDialog", () => {
     expect(body.parent_id).toBeUndefined();
   });
 
+  it("omits compute config by default", async () => {
+    await openDialog();
+    fireEvent.change(screen.getByPlaceholderText("e.g. SEO Agent"), {
+      target: { value: "Plain Agent" },
+    });
+
+    const createBtn = screen.getAllByRole("button").find((b) => b.textContent === "Create");
+    fireEvent.click(createBtn!);
+
+    await waitFor(() => expect(mockPost).toHaveBeenCalled());
+    const body = mockPost.mock.calls[0][1] as Record<string, unknown>;
+    expect(body.compute).toBeUndefined();
+    expect(body.model).toBe("anthropic:claude-opus-4-7");
+  });
+
+  it("sends display compute profile when desktop display is enabled", async () => {
+    await openDialog();
+    fireEvent.change(screen.getByPlaceholderText("e.g. SEO Agent"), {
+      target: { value: "Desktop Agent" },
+    });
+    fireEvent.click(screen.getByLabelText("Enable display"));
+
+    const createBtn = screen.getAllByRole("button").find((b) => b.textContent === "Create");
+    fireEvent.click(createBtn!);
+
+    await waitFor(() => expect(mockPost).toHaveBeenCalled());
+    const body = mockPost.mock.calls[0][1] as Record<string, unknown>;
+    expect(body.model).toBe("anthropic:claude-opus-4-7");
+    expect(body.compute).toEqual({
+      instance_type: "t3.xlarge",
+      volume: { root_gb: 80 },
+      display: {
+        mode: "desktop-control",
+        protocol: "novnc",
+        width: 1920,
+        height: 1080,
+      },
+    });
+  });
+
   it("renders gracefully when GET /workspaces fails", async () => {
     mockGet.mockRejectedValueOnce(new Error("Network error"));
     await openDialog();

canvas/src/components/tabs/DisplayTab.tsx

@@ -11,6 +11,7 @@ interface DisplayStatus {
   protocol?: string;
   width?: number;
   height?: number;
+  viewer_url?: string;
 }
 
 interface DisplayControlStatus {
@@ -93,6 +94,31 @@ export function DisplayTab({ workspaceId }: Props) {
     }
   };
 
+  const releaseControl = async () => {
+    const generation = requestGeneration.current;
+    const controlPath = `/workspaces/${workspaceId}/display/control`;
+    setControlBusy(true);
+    setControlError(null);
+    try {
+      const next = await api.post<DisplayControlStatus>(`${controlPath}/release`, {});
+      if (requestGeneration.current !== generation) return;
+      setControl(next);
+    } catch (err) {
+      if (requestGeneration.current !== generation) return;
+      setControlError("Failed to release control");
+      try {
+        const latest = await api.get<DisplayControlStatus>(controlPath);
+        if (requestGeneration.current !== generation) return;
+        setControl(latest);
+      } catch {
+        if (requestGeneration.current !== generation) return;
+        setControl(null);
+      }
+    } finally {
+      if (requestGeneration.current === generation) setControlBusy(false);
+    }
+  };
+
   if (error) {
     return (
       <div className="p-5">
@@ -185,7 +211,97 @@ export function DisplayTab({ workspaceId }: Props) {
     );
   }
 
-  return null;
+  return (
+    <div className="flex h-full min-h-[360px] flex-col bg-surface-sunken/30">
+      <div className="flex items-center justify-between gap-3 border-b border-line/50 px-4 py-3">
+        <div className="min-w-0">
+          <h3 className="text-sm font-medium text-ink">Desktop</h3>
+          <p className="mt-0.5 font-mono text-[10px] text-ink-mid">
+            {status.mode || "desktop-control"} · {status.protocol || "display"}
+          </p>
+        </div>
+        <DisplayControlBar
+          control={control}
+          controlBusy={controlBusy}
+          controlError={controlError}
+          onAcquire={acquireControl}
+          onRelease={releaseControl}
+        />
+      </div>
+      {status.viewer_url ? (
+        <iframe
+          title="Workspace desktop"
+          src={status.viewer_url}
+          className="min-h-0 flex-1 border-0 bg-black"
+          allow="clipboard-read; clipboard-write; fullscreen; pointer-lock"
+          referrerPolicy="no-referrer"
+        />
+      ) : (
+        <div className="flex flex-1 items-center justify-center p-8 text-center">
+          <div>
+            <h3 className="mb-1.5 text-sm font-medium text-ink">Display session is not ready.</h3>
+            <p className="max-w-xs text-[11px] leading-relaxed text-ink-mid">
+              This workspace has display configuration, but the desktop session URL is not available yet.
+            </p>
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}
+
+function DisplayControlBar({
+  control,
+  controlBusy,
+  controlError,
+  onAcquire,
+  onRelease,
+}: {
+  control: DisplayControlStatus | null;
+  controlBusy: boolean;
+  controlError: string | null;
+  onAcquire: () => void;
+  onRelease: () => void;
+}) {
+  return (
+    <div className="flex min-w-0 items-center gap-3">
+      {control && (
+        <div className="min-w-0 text-right">
+          <p className="truncate text-[11px] font-medium text-ink">
+            {control.controller === "none"
+              ? "No active controller"
+              : `Controlled by ${displayControlActorLabel(control)}`}
+          </p>
+          {control.expires_at && (
+            <p className="mt-0.5 truncate font-mono text-[10px] text-ink-mid">
+              Until {new Date(control.expires_at).toLocaleTimeString()}
+            </p>
+          )}
+          {controlError && <p className="mt-0.5 text-[10px] text-red-200">{controlError}</p>}
+        </div>
+      )}
+      {control?.controller === "none" && (
+        <button
+          type="button"
+          onClick={onAcquire}
+          disabled={controlBusy}
+          className="h-8 shrink-0 rounded border border-line bg-surface px-3 text-[11px] font-medium text-ink hover:bg-surface-elevated disabled:cursor-not-allowed disabled:opacity-60"
+        >
+          Take control
+        </button>
+      )}
+      {control?.controller === "user" && control.controlled_by === "admin-token" && (
+        <button
+          type="button"
+          onClick={onRelease}
+          disabled={controlBusy}
+          className="h-8 shrink-0 rounded border border-line bg-surface px-3 text-[11px] font-medium text-ink hover:bg-surface-elevated disabled:cursor-not-allowed disabled:opacity-60"
+        >
+          Release
+        </button>
+      )}
+    </div>
+  );
 }
 
 function displayControlActorLabel(control: DisplayControlStatus): string {

canvas/src/components/tabs/__tests__/DisplayTab.test.tsx

@@ -71,6 +71,61 @@ describe("DisplayTab", () => {
     });
   });
 
+  it("renders the desktop stream when a display session is available", async () => {
+    mockGet
+      .mockResolvedValueOnce({
+        available: true,
+        mode: "desktop-control",
+        protocol: "dcv",
+        width: 1920,
+        height: 1080,
+        viewer_url: "https://display.example.test/session/ws-display",
+      })
+      .mockResolvedValueOnce({
+        controller: "none",
+      });
+
+    render(<DisplayTab workspaceId="ws-display" />);
+
+    await waitFor(() => {
+      expect(screen.getByTitle("Workspace desktop")).toBeTruthy();
+    });
+    const frame = screen.getByTitle("Workspace desktop") as HTMLIFrameElement;
+    expect(frame.src).toBe("https://display.example.test/session/ws-display");
+    expect(screen.getByRole("button", { name: "Take control" })).toBeTruthy();
+  });
+
+  it("releases user display control", async () => {
+    mockGet
+      .mockResolvedValueOnce({
+        available: true,
+        mode: "desktop-control",
+        protocol: "dcv",
+        viewer_url: "https://display.example.test/session/ws-display",
+      })
+      .mockResolvedValueOnce({
+        controller: "user",
+        controlled_by: "admin-token",
+        expires_at: "2026-05-23T08:48:27Z",
+      });
+    mockPost.mockResolvedValueOnce({
+      controller: "none",
+    });
+
+    render(<DisplayTab workspaceId="ws-display" />);
+
+    await waitFor(() => {
+      expect(screen.getByRole("button", { name: "Release" })).toBeTruthy();
+    });
+
+    fireEvent.click(screen.getByRole("button", { name: "Release" }));
+
+    await waitFor(() => {
+      expect(screen.getByRole("button", { name: "Take control" })).toBeTruthy();
+    });
+    expect(mockPost).toHaveBeenCalledWith("/workspaces/ws-display/display/control/release", {});
+  });
+
   it("renders active display control locks as observe-only", async () => {
     mockGet
       .mockResolvedValueOnce({

workspace-server/internal/handlers/workspace_compute.go

@@ -6,6 +6,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"net/url"
+	"os"
+	"strings"
 
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/models"
@@ -15,6 +18,10 @@ import (
 const (
 	workspaceComputeDiskFloorGB   = 30
 	workspaceComputeDiskCeilingGB = 500
+	workspaceDisplayMinWidth      = 800
+	workspaceDisplayMaxWidth      = 3840
+	workspaceDisplayMinHeight     = 600
+	workspaceDisplayMaxHeight     = 2160
 )
 
 type workspaceDisplayResponse struct {
@@ -25,6 +32,7 @@ type workspaceDisplayResponse struct {
 	Width     int    `json:"width,omitempty"`
 	Height    int    `json:"height,omitempty"`
 	Status    string `json:"status,omitempty"`
+	ViewerURL string `json:"viewer_url,omitempty"`
 }
 
 var workspaceComputeInstanceAllowlist = map[string]struct{}{
@@ -54,12 +62,12 @@ func validateWorkspaceCompute(compute models.WorkspaceCompute) error {
 		return fmt.Errorf("unsupported compute.display.mode")
 	}
 	switch compute.Display.Protocol {
-	case "", "dcv":
+	case "", "dcv", "novnc":
 	default:
 		return fmt.Errorf("unsupported compute.display.protocol")
 	}
-	if compute.Display.Width < 0 || compute.Display.Height < 0 {
-		return fmt.Errorf("compute.display width/height must be non-negative")
+	if err := validateWorkspaceDisplayDimensions(compute.Display.Width, compute.Display.Height); err != nil {
+		return err
 	}
 	return nil
 }
@@ -71,13 +79,26 @@ func validateWorkspaceDisplayConfig(display models.WorkspaceComputeDisplay) erro
 		return fmt.Errorf("unsupported compute.display.mode")
 	}
 	switch display.Protocol {
-	case "", "dcv":
+	case "", "dcv", "novnc":
 	default:
 		return fmt.Errorf("unsupported compute.display.protocol")
 	}
-	if display.Width < 0 || display.Height < 0 {
+	if err := validateWorkspaceDisplayDimensions(display.Width, display.Height); err != nil {
+		return err
+	}
+	return nil
+}
+
+func validateWorkspaceDisplayDimensions(width, height int) error {
+	if width < 0 || height < 0 {
 		return fmt.Errorf("compute.display width/height must be non-negative")
 	}
+	if width != 0 && (width < workspaceDisplayMinWidth || width > workspaceDisplayMaxWidth) {
+		return fmt.Errorf("compute.display.width must be between %d and %d", workspaceDisplayMinWidth, workspaceDisplayMaxWidth)
+	}
+	if height != 0 && (height < workspaceDisplayMinHeight || height > workspaceDisplayMaxHeight) {
+		return fmt.Errorf("compute.display.height must be between %d and %d", workspaceDisplayMinHeight, workspaceDisplayMaxHeight)
+	}
 	return nil
 }
 
@@ -196,6 +217,18 @@ func (h *WorkspaceHandler) Display(c *gin.Context) {
 		})
 		return
 	}
+	if viewerURL := workspaceDisplayViewerURL(workspaceID); viewerURL != "" {
+		c.JSON(200, workspaceDisplayResponse{
+			Available: true,
+			Mode:      compute.Display.Mode,
+			Protocol:  compute.Display.Protocol,
+			Width:     compute.Display.Width,
+			Height:    compute.Display.Height,
+			Status:    "ready",
+			ViewerURL: viewerURL,
+		})
+		return
+	}
 	c.JSON(200, workspaceDisplayResponse{
 		Available: false,
 		Reason:    "display_session_unavailable",
@@ -206,3 +239,15 @@ func (h *WorkspaceHandler) Display(c *gin.Context) {
 		Status:    "not_configured",
 	})
 }
+
+func workspaceDisplayViewerURL(workspaceID string) string {
+	base := strings.TrimRight(os.Getenv("DISPLAY_VIEWER_BASE_URL"), "/")
+	if base == "" {
+		return ""
+	}
+	parsed, err := url.Parse(base)
+	if err != nil || parsed.Scheme != "https" || parsed.Host == "" {
+		return ""
+	}
+	return base + "/" + url.PathEscape(workspaceID)
+}

workspace-server/internal/handlers/workspace_compute_test.go

@@ -43,6 +43,20 @@ func TestValidateWorkspaceCompute_RejectsOutOfRangeRootVolume(t *testing.T) {
 	}
 }
 
+func TestValidateWorkspaceCompute_RejectsOutOfRangeDisplayDimensions(t *testing.T) {
+	for _, display := range []models.WorkspaceComputeDisplay{
+		{Mode: "desktop-control", Protocol: "novnc", Width: 799, Height: 1080},
+		{Mode: "desktop-control", Protocol: "novnc", Width: 3841, Height: 1080},
+		{Mode: "desktop-control", Protocol: "novnc", Width: 1920, Height: 599},
+		{Mode: "desktop-control", Protocol: "novnc", Width: 1920, Height: 2161},
+	} {
+		compute := models.WorkspaceCompute{Display: display}
+		if err := validateWorkspaceCompute(compute); err == nil {
+			t.Fatalf("validateWorkspaceCompute accepted display size %dx%d", display.Width, display.Height)
+		}
+	}
+}
+
 func TestWorkspaceComputeJSON_OmitsEmptyNestedSections(t *testing.T) {
 	got, err := workspaceComputeJSON(models.WorkspaceCompute{
 		InstanceType: "m6i.xlarge",
@@ -140,6 +154,7 @@ func TestBuildProvisionerConfig_CopiesComputeSizingFromPayload(t *testing.T) {
 			Compute: models.WorkspaceCompute{
 				InstanceType: "m6i.xlarge",
 				Volume:       models.WorkspaceComputeVolume{RootGB: 100},
+				Display:      models.WorkspaceComputeDisplay{Mode: "desktop-control", Protocol: "novnc", Width: 1920, Height: 1080},
 			},
 		},
 		nil,
@@ -153,6 +168,12 @@ func TestBuildProvisionerConfig_CopiesComputeSizingFromPayload(t *testing.T) {
 	if cfg.DiskGB != 100 {
 		t.Errorf("cfg.DiskGB = %d, want 100", cfg.DiskGB)
 	}
+	if cfg.Display.Mode != "desktop-control" || cfg.Display.Protocol != "novnc" {
+		t.Errorf("cfg.Display mode/protocol = %q/%q, want desktop-control/novnc", cfg.Display.Mode, cfg.Display.Protocol)
+	}
+	if cfg.Display.Width != 1920 || cfg.Display.Height != 1080 {
+		t.Errorf("cfg.Display size = %dx%d, want 1920x1080", cfg.Display.Width, cfg.Display.Height)
+	}
 }
 
 func TestWithStoredCompute_LoadsComputeForRestartPayloads(t *testing.T) {
@@ -216,7 +237,7 @@ func TestWorkspaceDisplay_DisplayConfiguredReturnsSessionUnavailableContract(t *
 
 	mock.ExpectQuery(`SELECT COALESCE\(compute, '\{\}'::jsonb\) FROM workspaces WHERE id = \$1`).
 		WithArgs("ws-display").
-		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"display":{"mode":"desktop-control","protocol":"dcv","width":1920,"height":1080}}`))
+		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"display":{"mode":"desktop-control","protocol":"novnc","width":1920,"height":1080}}`))
 
 	w := httptest.NewRecorder()
 	c, _ := gin.CreateTestContext(w)
@@ -241,8 +262,8 @@ func TestWorkspaceDisplay_DisplayConfiguredReturnsSessionUnavailableContract(t *
 	if resp["status"] != "not_configured" {
 		t.Fatalf("status = %v, want not_configured", resp["status"])
 	}
-	if resp["mode"] != "desktop-control" || resp["protocol"] != "dcv" {
-		t.Fatalf("mode/protocol = %v/%v, want desktop-control/dcv", resp["mode"], resp["protocol"])
+	if resp["mode"] != "desktop-control" || resp["protocol"] != "novnc" {
+		t.Fatalf("mode/protocol = %v/%v, want desktop-control/novnc", resp["mode"], resp["protocol"])
 	}
 	if resp["width"] != float64(1920) || resp["height"] != float64(1080) {
 		t.Fatalf("width/height = %v/%v, want 1920/1080", resp["width"], resp["height"])
@@ -255,6 +276,83 @@ func TestWorkspaceDisplay_DisplayConfiguredReturnsSessionUnavailableContract(t *
 	}
 }
 
+func TestWorkspaceDisplay_DisplayConfiguredWithViewerBaseReturnsAvailableSession(t *testing.T) {
+	mock := setupTestDB(t)
+	setupTestRedis(t)
+	t.Setenv("DISPLAY_VIEWER_BASE_URL", "https://display.example.test/sessions")
+	handler := NewWorkspaceHandler(newTestBroadcaster(), nil, "http://localhost:8080", t.TempDir())
+
+	mock.ExpectQuery(`SELECT COALESCE\(compute, '\{\}'::jsonb\) FROM workspaces WHERE id = \$1`).
+		WithArgs("ws-display").
+		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"display":{"mode":"desktop-control","protocol":"novnc","width":1920,"height":1080}}`))
+
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Params = gin.Params{{Key: "id", Value: "ws-display"}}
+	c.Request = httptest.NewRequest("GET", "/workspaces/ws-display/display", nil)
+
+	handler.Display(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+	var resp map[string]interface{}
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to parse display response: %v", err)
+	}
+	if resp["available"] != true {
+		t.Fatalf("available = %v, want true", resp["available"])
+	}
+	if resp["viewer_url"] != "https://display.example.test/sessions/ws-display" {
+		t.Fatalf("viewer_url = %v, want workspace viewer URL", resp["viewer_url"])
+	}
+	if resp["reason"] != nil {
+		t.Fatalf("reason = %v, want omitted", resp["reason"])
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+func TestWorkspaceDisplay_DisplayConfiguredWithInvalidViewerBaseReturnsUnavailable(t *testing.T) {
+	mock := setupTestDB(t)
+	setupTestRedis(t)
+	t.Setenv("DISPLAY_VIEWER_BASE_URL", "http://display.example.test/sessions")
+	handler := NewWorkspaceHandler(newTestBroadcaster(), nil, "http://localhost:8080", t.TempDir())
+
+	workspaceID := "ws-display"
+	mock.ExpectQuery(`SELECT COALESCE\(compute, '\{\}'::jsonb\) FROM workspaces WHERE id = \$1`).
+		WithArgs(workspaceID).
+		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"display":{"mode":"desktop-control","protocol":"novnc","width":1920,"height":1080}}`))
+
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Params = gin.Params{{Key: "id", Value: workspaceID}}
+	c.Request = httptest.NewRequest("GET", "/workspaces/"+workspaceID+"/display", nil)
+
+	handler.Display(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected status 200, got %d: %s", w.Code, w.Body.String())
+	}
+	var resp map[string]interface{}
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to parse display response: %v", err)
+	}
+	if resp["available"] != false {
+		t.Fatalf("available = %v, want false", resp["available"])
+	}
+	if resp["viewer_url"] != nil {
+		t.Fatalf("viewer_url = %v, want omitted for invalid viewer base", resp["viewer_url"])
+	}
+	if resp["reason"] != "display_session_unavailable" {
+		t.Fatalf("reason = %v, want display_session_unavailable", resp["reason"])
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
 func TestWorkspaceDisplay_IgnoresUnrelatedStoredComputeSizingDrift(t *testing.T) {
 	mock := setupTestDB(t)
 	setupTestRedis(t)
@@ -262,7 +360,7 @@ func TestWorkspaceDisplay_IgnoresUnrelatedStoredComputeSizingDrift(t *testing.T)
 
 	mock.ExpectQuery(`SELECT COALESCE\(compute, '\{\}'::jsonb\) FROM workspaces WHERE id = \$1`).
 		WithArgs("ws-display-sizing-drift").
-		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"instance_type":"old.large","display":{"mode":"desktop-control","protocol":"dcv","width":1920,"height":1080}}`))
+		WillReturnRows(sqlmock.NewRows([]string{"compute"}).AddRow(`{"instance_type":"old.large","display":{"mode":"desktop-control","protocol":"novnc","width":1920,"height":1080}}`))
 
 	w := httptest.NewRecorder()
 	c, _ := gin.CreateTestContext(w)

workspace-server/internal/handlers/workspace_provision.go

@@ -288,16 +288,22 @@ func (h *WorkspaceHandler) buildProvisionerConfig(
 	}
 
 	return provisioner.WorkspaceConfig{
-		WorkspaceID:        workspaceID,
-		TemplatePath:       templatePath,
-		ConfigFiles:        configFiles,
-		PluginsPath:        pluginsPath,
-		WorkspacePath:      workspacePath,
-		WorkspaceAccess:    workspaceAccess,
-		Tier:               payload.Tier,
-		Runtime:            payload.Runtime,
-		InstanceType:       payload.Compute.InstanceType,
-		DiskGB:             int32(payload.Compute.Volume.RootGB),
+		WorkspaceID:     workspaceID,
+		TemplatePath:    templatePath,
+		ConfigFiles:     configFiles,
+		PluginsPath:     pluginsPath,
+		WorkspacePath:   workspacePath,
+		WorkspaceAccess: workspaceAccess,
+		Tier:            payload.Tier,
+		Runtime:         payload.Runtime,
+		InstanceType:    payload.Compute.InstanceType,
+		DiskGB:          int32(payload.Compute.Volume.RootGB),
+		Display: provisioner.WorkspaceDisplayConfig{
+			Mode:     payload.Compute.Display.Mode,
+			Width:    payload.Compute.Display.Width,
+			Height:   payload.Compute.Display.Height,
+			Protocol: payload.Compute.Display.Protocol,
+		},
 		EnvVars:            envVars,
 		PlatformURL:        h.platformURL,
 		AwarenessURL:       os.Getenv("AWARENESS_URL"),

workspace-server/internal/provisioner/cp_provisioner.go

@@ -152,14 +152,15 @@ func (p *CPProvisioner) adminAuthHeaders(req *http.Request) {
 }
 
 type cpProvisionRequest struct {
-	OrgID        string            `json:"org_id"`
-	WorkspaceID  string            `json:"workspace_id"`
-	Runtime      string            `json:"runtime"`
-	Tier         int               `json:"tier"`
-	InstanceType string            `json:"instance_type,omitempty"`
-	DiskGB       int32             `json:"disk_gb,omitempty"`
-	PlatformURL  string            `json:"platform_url"`
-	Env          map[string]string `json:"env"`
+	OrgID        string                 `json:"org_id"`
+	WorkspaceID  string                 `json:"workspace_id"`
+	Runtime      string                 `json:"runtime"`
+	Tier         int                    `json:"tier"`
+	InstanceType string                 `json:"instance_type,omitempty"`
+	DiskGB       int32                  `json:"disk_gb,omitempty"`
+	Display      WorkspaceDisplayConfig `json:"display,omitempty"`
+	PlatformURL  string                 `json:"platform_url"`
+	Env          map[string]string      `json:"env"`
 	// ConfigFiles are template + generated config files to write into the
 	// EC2 instance's /configs directory. OFFSEC-010: collected by
 	// collectCPConfigFiles which rejects symlinks and non-regular files
@@ -214,6 +215,7 @@ func (p *CPProvisioner) Start(ctx context.Context, cfg WorkspaceConfig) (string,
 		Tier:         cfg.Tier,
 		InstanceType: cfg.InstanceType,
 		DiskGB:       cfg.DiskGB,
+		Display:      cfg.Display,
 		PlatformURL:  cfg.PlatformURL,
 		Env:          env,
 		ConfigFiles:  configFiles,

workspace-server/internal/provisioner/cp_provisioner_test.go

@@ -197,6 +197,12 @@ func TestStart_HappyPath(t *testing.T) {
 		if body.DiskGB != 100 {
 			t.Errorf("disk_gb = %d, want 100", body.DiskGB)
 		}
+		if body.Display.Mode != "desktop-control" || body.Display.Protocol != "novnc" {
+			t.Errorf("display mode/protocol = %q/%q, want desktop-control/novnc", body.Display.Mode, body.Display.Protocol)
+		}
+		if body.Display.Width != 1920 || body.Display.Height != 1080 {
+			t.Errorf("display size = %dx%d, want 1920x1080", body.Display.Width, body.Display.Height)
+		}
 		w.WriteHeader(http.StatusCreated)
 		_, _ = io.WriteString(w, `{"instance_id":"i-abc123","state":"pending"}`)
 	}))
@@ -212,6 +218,7 @@ func TestStart_HappyPath(t *testing.T) {
 	id, err := p.Start(context.Background(), WorkspaceConfig{
 		WorkspaceID: "ws-1", Runtime: "python", Tier: 1, PlatformURL: "http://tenant",
 		InstanceType: "m6i.xlarge", DiskGB: 100,
+		Display: WorkspaceDisplayConfig{Mode: "desktop-control", Protocol: "novnc", Width: 1920, Height: 1080},
 	})
 	if err != nil {
 		t.Fatalf("Start: %v", err)

workspace-server/internal/provisioner/provisioner.go

@@ -97,9 +97,10 @@ type WorkspaceConfig struct {
 	PluginsPath        string            // Host path to plugins directory (mounted at /plugins)
 	WorkspacePath      string            // Host path to bind-mount as /workspace (if empty, uses Docker named volume)
 	Tier               int
-	Runtime            string            // "langgraph" (default) or "claude-code", "codex", "ollama", "custom"
-	InstanceType       string            // Optional CP EC2 instance type override (SaaS only)
-	DiskGB             int32             // Optional CP root volume size override in GiB (SaaS only)
+	Runtime            string // "langgraph" (default) or "claude-code", "codex", "ollama", "custom"
+	InstanceType       string // Optional CP EC2 instance type override (SaaS only)
+	DiskGB             int32  // Optional CP root volume size override in GiB (SaaS only)
+	Display            WorkspaceDisplayConfig
 	EnvVars            map[string]string // Additional env vars (API keys, etc.)
 	PlatformURL        string
 	AwarenessURL       string
@@ -122,6 +123,13 @@ type WorkspaceConfig struct {
 	Image string
 }
 
+type WorkspaceDisplayConfig struct {
+	Mode     string `json:"mode,omitempty"`
+	Width    int    `json:"width,omitempty"`
+	Height   int    `json:"height,omitempty"`
+	Protocol string `json:"protocol,omitempty"`
+}
+
 // selectImage resolves the final Docker image ref for a workspace. The handler
 // layer is the source of truth — if it set cfg.Image (the digest-pinned form
 // supplied by CP, the SSOT for runtime image pins; molecule-core's own