diff --git a/packages/shared/src/constants.ts b/packages/shared/src/constants.ts
index c2f8f807889..b7c7917ed94 100644
--- a/packages/shared/src/constants.ts
+++ b/packages/shared/src/constants.ts
@@ -961,6 +961,7 @@ export const PLUGIN_UI_SLOT_ENTITY_TYPES = [
   "goal",
   "run",
   "comment",
+  "execution_workspace",
 ] as const;
 export type PluginUiSlotEntityType = (typeof PLUGIN_UI_SLOT_ENTITY_TYPES)[number];
 
diff --git a/packages/shared/src/validators/plugin.test.ts b/packages/shared/src/validators/plugin.test.ts
index ccea0d6a3f6..5369902c12b 100644
--- a/packages/shared/src/validators/plugin.test.ts
+++ b/packages/shared/src/validators/plugin.test.ts
@@ -104,4 +104,28 @@ describe("plugin UI slot validators", () => {
     if (parsed.success) return;
     expect(parsed.error.issues.some((issue) => issue.message.includes("reserved by the host"))).toBe(true);
   });
+
+  it("accepts execution_workspace as a detailTab entityType", () => {
+    const parsed = pluginUiSlotDeclarationSchema.parse({
+      type: "detailTab",
+      id: "workspace-diff-viewer",
+      displayName: "Diff",
+      exportName: "WorkspaceDiffViewer",
+      entityTypes: ["execution_workspace"],
+    });
+
+    expect(parsed.entityTypes).toEqual(["execution_workspace"]);
+  });
+
+  it("accepts execution_workspace as a toolbarButton entityType", () => {
+    const parsed = pluginUiSlotDeclarationSchema.parse({
+      type: "toolbarButton",
+      id: "workspace-open-diff",
+      displayName: "Open diff",
+      exportName: "OpenWorkspaceDiffButton",
+      entityTypes: ["execution_workspace"],
+    });
+
+    expect(parsed.entityTypes).toEqual(["execution_workspace"]);
+  });
 });
diff --git a/ui/src/pages/ExecutionWorkspaceDetail.test.tsx b/ui/src/pages/ExecutionWorkspaceDetail.test.tsx
new file mode 100644
index 00000000000..7bb4ca748a5
--- /dev/null
+++ b/ui/src/pages/ExecutionWorkspaceDetail.test.tsx
@@ -0,0 +1,251 @@
+// @vitest-environment jsdom
+
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import type { ExecutionWorkspace, Project } from "@paperclipai/shared";
+import { act, type ReactNode } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { ExecutionWorkspaceDetail } from "./ExecutionWorkspaceDetail";
+
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+const mockExecutionWorkspacesApi = vi.hoisted(() => ({
+  get: vi.fn(),
+  update: vi.fn(),
+  listWorkspaceOperations: vi.fn(),
+  controlRuntimeCommands: vi.fn(),
+}));
+const mockProjectsApi = vi.hoisted(() => ({ get: vi.fn() }));
+const mockIssuesApi = vi.hoisted(() => ({ get: vi.fn(), list: vi.fn() }));
+const mockAgentsApi = vi.hoisted(() => ({ list: vi.fn() }));
+const mockHeartbeatsApi = vi.hoisted(() => ({ liveRunsForCompany: vi.fn() }));
+const mockRoutinesApi = vi.hoisted(() => ({ list: vi.fn(), get: vi.fn(), run: vi.fn() }));
+const mockNavigate = vi.hoisted(() => vi.fn());
+const mockSetBreadcrumbs = vi.hoisted(() => vi.fn());
+const mockUsePluginSlots = vi.hoisted(() => vi.fn());
+const mockPluginSlotOutlet = vi.hoisted(() => vi.fn());
+const mockPluginSlotMount = vi.hoisted(() => vi.fn());
+
+vi.mock("../api/execution-workspaces", () => ({ executionWorkspacesApi: mockExecutionWorkspacesApi }));
+vi.mock("../api/projects", () => ({ projectsApi: mockProjectsApi }));
+vi.mock("../api/issues", () => ({ issuesApi: mockIssuesApi }));
+vi.mock("../api/agents", () => ({ agentsApi: mockAgentsApi }));
+vi.mock("../api/heartbeats", () => ({ heartbeatsApi: mockHeartbeatsApi }));
+vi.mock("../api/routines", () => ({ routinesApi: mockRoutinesApi }));
+
+vi.mock("@/lib/router", () => ({
+  Link: ({ children, to }: { children?: ReactNode; to: string }) => <a href={to}>{children}</a>,
+  Navigate: ({ to }: { to: string }) => <div data-testid="navigate">{to}</div>,
+  useLocation: () => ({ pathname: "/execution-workspaces/workspace-1/issues", search: "", hash: "", state: null }),
+  useNavigate: () => mockNavigate,
+  useParams: () => ({ workspaceId: "workspace-1" }),
+}));
+
+vi.mock("../context/CompanyContext", () => ({
+  useCompany: () => ({
+    companies: [{ id: "company-1", issuePrefix: "PAP" }],
+    selectedCompanyId: "company-1",
+    setSelectedCompanyId: vi.fn(),
+  }),
+}));
+vi.mock("../context/BreadcrumbContext", () => ({ useBreadcrumbs: () => ({ setBreadcrumbs: mockSetBreadcrumbs }) }));
+vi.mock("../context/ToastContext", () => ({ useToastActions: () => ({ pushToast: vi.fn() }) }));
+
+vi.mock("@/plugins/slots", () => ({
+  PluginSlotMount: (props: unknown) => {
+    mockPluginSlotMount(props);
+    return <div data-testid="plugin-slot-mount" />;
+  },
+  PluginSlotOutlet: (props: unknown) => {
+    mockPluginSlotOutlet(props);
+    return <div data-testid="plugin-slot-outlet" />;
+  },
+  usePluginSlots: (filters: unknown) => {
+    mockUsePluginSlots(filters);
+    return { slots: [], isLoading: false, errorMessage: null };
+  },
+}));
+
+vi.mock("../components/IssuesList", () => ({
+  IssuesList: () => <div data-testid="issues-list" />,
+}));
+vi.mock("../components/ExecutionWorkspaceCloseDialog", () => ({
+  ExecutionWorkspaceCloseDialog: () => null,
+}));
+vi.mock("../components/RoutineRunVariablesDialog", () => ({
+  RoutineRunVariablesDialog: () => null,
+}));
+vi.mock("../components/WorkspaceRuntimeControls", () => ({
+  buildWorkspaceRuntimeControlSections: () => [],
+  WorkspaceRuntimeQuickControls: () => <div data-testid="runtime-quick-controls" />,
+  WorkspaceRuntimeControls: () => <div data-testid="runtime-controls" />,
+}));
+vi.mock("../components/PageTabBar", () => ({
+  PageTabBar: ({ items }: { items: Array<{ value: string; label: string }> }) => (
+    <div data-testid="page-tab-bar">
+      {items.map((item) => (
+        <button key={item.value} data-tab-value={item.value} type="button">{item.label}</button>
+      ))}
+    </div>
+  ),
+}));
+vi.mock("../components/CopyText", () => ({ CopyText: () => null }));
+
+function workspace(overrides: Partial<ExecutionWorkspace> = {}): ExecutionWorkspace {
+  const now = new Date("2026-05-01T00:00:00Z");
+  return {
+    id: "workspace-1",
+    companyId: "company-1",
+    projectId: "project-1",
+    projectWorkspaceId: null,
+    sourceIssueId: null,
+    mode: "local",
+    strategyType: "local_worktree",
+    name: "Diff worktree",
+    status: "active",
+    cwd: "/tmp/workspace-1",
+    repoUrl: null,
+    baseRef: null,
+    branchName: null,
+    providerType: "local",
+    providerRef: null,
+    derivedFromExecutionWorkspaceId: null,
+    lastUsedAt: now,
+    openedAt: now,
+    closedAt: null,
+    cleanupEligibleAt: null,
+    cleanupReason: null,
+    config: null,
+    metadata: null,
+    runtimeServices: [],
+    createdAt: now,
+    updatedAt: now,
+    ...overrides,
+  } as ExecutionWorkspace;
+}
+
+function project(overrides: Partial<Project> = {}): Project {
+  const now = new Date("2026-05-01T00:00:00Z");
+  return {
+    id: "project-1",
+    companyId: "company-1",
+    urlKey: "project-1",
+    goalId: null,
+    goalIds: [],
+    goals: [],
+    name: "Test Project",
+    description: null,
+    status: "in_progress",
+    leadAgentId: null,
+    targetDate: null,
+    color: "#14b8a6",
+    env: null,
+    pauseReason: null,
+    pausedAt: null,
+    executionWorkspacePolicy: null,
+    codebase: {
+      workspaceId: null,
+      repoUrl: null,
+      repoRef: null,
+      defaultRef: null,
+      repoName: null,
+      localFolder: null,
+      managedFolder: "/tmp/project-1",
+      effectiveLocalFolder: "/tmp/project-1",
+      origin: "managed_checkout",
+    },
+    workspaces: [],
+    primaryWorkspace: null,
+    managedByPlugin: null,
+    archivedAt: null,
+    createdAt: now,
+    updatedAt: now,
+    ...overrides,
+  };
+}
+
+async function flush() {
+  await new Promise((resolve) => setTimeout(resolve, 0));
+  await new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+describe("ExecutionWorkspaceDetail plugin slots", () => {
+  let root: Root | null = null;
+  let container: HTMLDivElement;
+
+  beforeEach(() => {
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    mockExecutionWorkspacesApi.get.mockResolvedValue(workspace());
+    mockExecutionWorkspacesApi.listWorkspaceOperations.mockResolvedValue([]);
+    mockProjectsApi.get.mockResolvedValue(project());
+    mockIssuesApi.list.mockResolvedValue([]);
+    mockAgentsApi.list.mockResolvedValue([]);
+    mockRoutinesApi.list.mockResolvedValue([]);
+    mockHeartbeatsApi.liveRunsForCompany.mockResolvedValue([]);
+  });
+
+  afterEach(() => {
+    act(() => root?.unmount());
+    root = null;
+    container.remove();
+    vi.clearAllMocks();
+  });
+
+  async function render() {
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    await act(async () => {
+      root = createRoot(container);
+      root.render(
+        <QueryClientProvider client={queryClient}>
+          <ExecutionWorkspaceDetail />
+        </QueryClientProvider>,
+      );
+    });
+    await act(async () => {
+      await flush();
+    });
+  }
+
+  it("scopes the plugin detail-tab discovery to execution_workspace and the workspace's company", async () => {
+    await render();
+
+    const enabledDetailTabFilters = mockUsePluginSlots.mock.calls
+      .map(([filters]) => filters as { slotTypes: string[]; entityType: string; companyId: string | null; enabled?: boolean })
+      .filter((filters) => filters.slotTypes.includes("detailTab") && filters.enabled !== false);
+
+    expect(enabledDetailTabFilters.length).toBeGreaterThan(0);
+    for (const filters of enabledDetailTabFilters) {
+      expect(filters.entityType).toBe("execution_workspace");
+      expect(filters.companyId).toBe("company-1");
+    }
+  });
+
+  it("mounts a toolbar PluginSlotOutlet with execution_workspace context", async () => {
+    await render();
+
+    const outletCalls = mockPluginSlotOutlet.mock.calls.map(([props]) => props as {
+      slotTypes: string[];
+      entityType: string;
+      context: { entityId: string; entityType: string; companyId: string; projectId: string };
+    });
+    const toolbarOutlet = outletCalls.find((props) => props.slotTypes.includes("toolbarButton"));
+    expect(toolbarOutlet).toBeDefined();
+    expect(toolbarOutlet?.entityType).toBe("execution_workspace");
+    expect(toolbarOutlet?.context).toMatchObject({
+      entityId: "workspace-1",
+      entityType: "execution_workspace",
+      companyId: "company-1",
+      projectId: "project-1",
+    });
+  });
+
+  it("does not mount plugin slots scoped to other entity types", async () => {
+    await render();
+
+    const outletCalls = mockPluginSlotOutlet.mock.calls.map(([props]) => props as { entityType: string });
+    for (const props of outletCalls) {
+      expect(props.entityType).toBe("execution_workspace");
+    }
+  });
+});
diff --git a/ui/src/pages/ExecutionWorkspaceDetail.tsx b/ui/src/pages/ExecutionWorkspaceDetail.tsx
index f541616c07b..c744fcf7e7c 100644
--- a/ui/src/pages/ExecutionWorkspaceDetail.tsx
+++ b/ui/src/pages/ExecutionWorkspaceDetail.tsx
@@ -19,6 +19,7 @@ import { projectsApi } from "../api/projects";
 import { routinesApi } from "../api/routines";
 import { IssuesList } from "../components/IssuesList";
 import { PageTabBar } from "../components/PageTabBar";
+import { PluginSlotMount, PluginSlotOutlet, usePluginSlots } from "@/plugins/slots";
 import {
   RoutineRunVariablesDialog,
   type RoutineRunDialogSubmitData,
@@ -54,9 +55,15 @@ type WorkspaceFormState = {
   workspaceRuntime: string;
 };
 
-type ExecutionWorkspaceTab = "services" | "configuration" | "runtime_logs" | "issues" | "routines";
+type ExecutionWorkspaceBaseTab = "services" | "configuration" | "runtime_logs" | "issues" | "routines";
+type ExecutionWorkspacePluginTab = `plugin:${string}`;
+type ExecutionWorkspaceTab = ExecutionWorkspaceBaseTab | ExecutionWorkspacePluginTab;
 
-function resolveExecutionWorkspaceTab(pathname: string, workspaceId: string): ExecutionWorkspaceTab | null {
+function isExecutionWorkspacePluginTab(value: string | null): value is ExecutionWorkspacePluginTab {
+  return typeof value === "string" && value.startsWith("plugin:");
+}
+
+function resolveExecutionWorkspaceTab(pathname: string, workspaceId: string): ExecutionWorkspaceBaseTab | null {
   const segments = pathname.split("/").filter(Boolean);
   const executionWorkspacesIndex = segments.indexOf("execution-workspaces");
   if (executionWorkspacesIndex === -1 || segments[executionWorkspacesIndex + 1] !== workspaceId) return null;
@@ -69,7 +76,7 @@ function resolveExecutionWorkspaceTab(pathname: string, workspaceId: string): Ex
   return null;
 }
 
-function executionWorkspaceTabPath(workspaceId: string, tab: ExecutionWorkspaceTab) {
+function executionWorkspaceTabPath(workspaceId: string, tab: ExecutionWorkspaceBaseTab) {
   const segment = tab === "runtime_logs" ? "runtime-logs" : tab;
   return `/execution-workspaces/${workspaceId}/${segment}`;
 }
@@ -536,7 +543,12 @@ export function ExecutionWorkspaceDetail() {
   const [errorMessage, setErrorMessage] = useState<string | null>(null);
   const [runtimeActionErrorMessage, setRuntimeActionErrorMessage] = useState<string | null>(null);
   const [runtimeActionMessage, setRuntimeActionMessage] = useState<string | null>(null);
-  const activeTab = workspaceId ? resolveExecutionWorkspaceTab(location.pathname, workspaceId) : null;
+  const activeRouteTab = workspaceId ? resolveExecutionWorkspaceTab(location.pathname, workspaceId) : null;
+  const pluginTabFromSearch = useMemo(() => {
+    const tab = new URLSearchParams(location.search).get("tab");
+    return isExecutionWorkspacePluginTab(tab) ? tab : null;
+  }, [location.search]);
+  const activeTab: ExecutionWorkspaceTab | null = activeRouteTab ?? pluginTabFromSearch;
 
   const workspaceQuery = useQuery({
     queryKey: queryKeys.executionWorkspaces.detail(workspaceId!),
@@ -580,6 +592,21 @@ export function ExecutionWorkspaceDetail() {
     () => project?.workspaces.find((item) => item.id === workspace?.projectWorkspaceId) ?? null,
     [project, workspace?.projectWorkspaceId],
   );
+
+  const { slots: workspacePluginDetailSlots } = usePluginSlots({
+    slotTypes: ["detailTab"],
+    entityType: "execution_workspace",
+    companyId: workspace?.companyId ?? null,
+    enabled: !!workspace?.companyId,
+  });
+  const workspacePluginTabItems = useMemo(
+    () => workspacePluginDetailSlots.map((slot) => ({
+      value: `plugin:${slot.pluginKey}:${slot.id}` as ExecutionWorkspacePluginTab,
+      label: slot.displayName,
+      slot,
+    })),
+    [workspacePluginDetailSlots],
+  );
   const inheritedRuntimeConfig = linkedProjectWorkspace?.runtimeConfig?.workspaceRuntime ?? null;
   const effectiveRuntimeConfig = workspace?.config?.workspaceRuntime ?? inheritedRuntimeConfig;
   const runtimeConfigSource =
@@ -684,11 +711,23 @@ export function ExecutionWorkspaceDetail() {
   });
   const pendingRuntimeAction = controlRuntimeServices.isPending ? controlRuntimeServices.variables ?? null : null;
 
+  const pluginSlotContext = {
+    companyId: workspace.companyId,
+    projectId: workspace.projectId,
+    entityId: workspace.id,
+    entityType: "execution_workspace" as const,
+  };
+  const activePluginTab = workspacePluginTabItems.find((item) => item.value === activeTab) ?? null;
+
   if (workspaceId && activeTab === null) {
     return <LegacyWorkspaceTabRedirect workspaceId={workspaceId} />;
   }
 
   const handleTabChange = (tab: ExecutionWorkspaceTab) => {
+    if (isExecutionWorkspacePluginTab(tab)) {
+      navigate(`/execution-workspaces/${workspace.id}?tab=${encodeURIComponent(tab)}`);
+      return;
+    }
     navigate(executionWorkspaceTabPath(workspace.id, tab));
   };
 
@@ -731,6 +770,15 @@ export function ExecutionWorkspaceDetail() {
         {runtimeActionErrorMessage ? <p className="text-sm text-destructive">{runtimeActionErrorMessage}</p> : null}
         {!runtimeActionErrorMessage && runtimeActionMessage ? <p className="text-sm text-muted-foreground">{runtimeActionMessage}</p> : null}
 
+        <PluginSlotOutlet
+          slotTypes={["toolbarButton", "contextMenuItem"]}
+          entityType="execution_workspace"
+          context={pluginSlotContext}
+          className="flex flex-wrap gap-2"
+          itemClassName="inline-flex"
+          missingBehavior="placeholder"
+        />
+
         <Tabs value={activeTab ?? "issues"} onValueChange={(value) => handleTabChange(value as ExecutionWorkspaceTab)}>
           <PageTabBar
             items={[
@@ -739,6 +787,7 @@ export function ExecutionWorkspaceDetail() {
               { value: "configuration", label: "Configuration" },
               { value: "runtime_logs", label: "Runtime logs" },
               { value: "routines", label: "Routines" },
+              ...workspacePluginTabItems.map((item) => ({ value: item.value, label: item.label })),
             ]}
             align="start"
             value={activeTab ?? "issues"}
@@ -1128,6 +1177,12 @@ export function ExecutionWorkspaceDetail() {
             error={linkedIssuesQuery.error as Error | null}
             project={project}
           />
+        ) : activePluginTab ? (
+          <PluginSlotMount
+            slot={activePluginTab.slot}
+            context={pluginSlotContext}
+            missingBehavior="placeholder"
+          />
         ) : (
           <ExecutionWorkspaceRoutinesList
             workspace={workspace}