Add project workspaces tab

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/App.tsx

@@ -144,6 +144,7 @@ function boardRoutes() {
       <Route path="projects/:projectId/overview" element={<ProjectDetail />} />
       <Route path="projects/:projectId/issues" element={<ProjectDetail />} />
       <Route path="projects/:projectId/issues/:filter" element={<ProjectDetail />} />
+      <Route path="projects/:projectId/workspaces" element={<ProjectDetail />} />
       <Route path="projects/:projectId/configuration" element={<ProjectDetail />} />
       <Route path="projects/:projectId/budget" element={<ProjectDetail />} />
       <Route path="issues" element={<Issues />} />

ui/src/lib/project-workspaces-tab.test.ts

@@ -0,0 +1,198 @@
+import { describe, expect, it } from "vitest";
+import type { ExecutionWorkspace, Issue, Project, ProjectWorkspace } from "@paperclipai/shared";
+import { buildProjectWorkspaceSummaries } from "./project-workspaces-tab";
+
+function createProjectWorkspace(overrides: Partial<ProjectWorkspace>): ProjectWorkspace {
+  return {
+    id: overrides.id ?? "workspace-default",
+    companyId: overrides.companyId ?? "company-1",
+    projectId: overrides.projectId ?? "project-1",
+    name: overrides.name ?? "paperclip",
+    sourceType: overrides.sourceType ?? "local_path",
+    cwd: overrides.cwd ?? "/repo",
+    repoUrl: overrides.repoUrl ?? null,
+    repoRef: overrides.repoRef ?? null,
+    defaultRef: overrides.defaultRef ?? null,
+    visibility: overrides.visibility ?? "default",
+    setupCommand: overrides.setupCommand ?? null,
+    cleanupCommand: overrides.cleanupCommand ?? null,
+    remoteProvider: overrides.remoteProvider ?? null,
+    remoteWorkspaceRef: overrides.remoteWorkspaceRef ?? null,
+    sharedWorkspaceKey: overrides.sharedWorkspaceKey ?? null,
+    metadata: overrides.metadata ?? null,
+    isPrimary: overrides.isPrimary ?? false,
+    runtimeServices: overrides.runtimeServices ?? [],
+    createdAt: overrides.createdAt ?? new Date("2026-03-20T00:00:00Z"),
+    updatedAt: overrides.updatedAt ?? new Date("2026-03-20T00:00:00Z"),
+  };
+}
+
+function createIssue(overrides: Partial<Issue>): Issue {
+  return {
+    id: overrides.id ?? "issue-1",
+    companyId: overrides.companyId ?? "company-1",
+    projectId: overrides.projectId ?? "project-1",
+    projectWorkspaceId: overrides.projectWorkspaceId ?? null,
+    goalId: overrides.goalId ?? null,
+    parentId: overrides.parentId ?? null,
+    title: overrides.title ?? "Issue",
+    description: overrides.description ?? null,
+    status: overrides.status ?? "todo",
+    priority: overrides.priority ?? "medium",
+    assigneeAgentId: overrides.assigneeAgentId ?? null,
+    assigneeUserId: overrides.assigneeUserId ?? null,
+    checkoutRunId: overrides.checkoutRunId ?? null,
+    executionRunId: overrides.executionRunId ?? null,
+    executionAgentNameKey: overrides.executionAgentNameKey ?? null,
+    executionLockedAt: overrides.executionLockedAt ?? null,
+    createdByAgentId: overrides.createdByAgentId ?? null,
+    createdByUserId: overrides.createdByUserId ?? null,
+    issueNumber: overrides.issueNumber ?? null,
+    identifier: overrides.identifier ?? null,
+    requestDepth: overrides.requestDepth ?? 0,
+    billingCode: overrides.billingCode ?? null,
+    assigneeAdapterOverrides: overrides.assigneeAdapterOverrides ?? null,
+    executionWorkspaceId: overrides.executionWorkspaceId ?? null,
+    executionWorkspacePreference: overrides.executionWorkspacePreference ?? null,
+    executionWorkspaceSettings: overrides.executionWorkspaceSettings ?? null,
+    startedAt: overrides.startedAt ?? null,
+    completedAt: overrides.completedAt ?? null,
+    cancelledAt: overrides.cancelledAt ?? null,
+    hiddenAt: overrides.hiddenAt ?? null,
+    createdAt: overrides.createdAt ?? new Date("2026-03-20T00:00:00Z"),
+    updatedAt: overrides.updatedAt ?? new Date("2026-03-20T00:00:00Z"),
+  } as Issue;
+}
+
+function createExecutionWorkspace(overrides: Partial<ExecutionWorkspace>): ExecutionWorkspace {
+  return {
+    id: overrides.id ?? "exec-1",
+    companyId: overrides.companyId ?? "company-1",
+    projectId: overrides.projectId ?? "project-1",
+    projectWorkspaceId: overrides.projectWorkspaceId ?? "workspace-default",
+    sourceIssueId: overrides.sourceIssueId ?? null,
+    mode: overrides.mode ?? "isolated_workspace",
+    strategyType: overrides.strategyType ?? "git_worktree",
+    name: overrides.name ?? "PAP-893",
+    status: overrides.status ?? "active",
+    cwd: overrides.cwd ?? "/repo/.worktrees/PAP-893",
+    repoUrl: overrides.repoUrl ?? null,
+    baseRef: overrides.baseRef ?? "public-gh/master",
+    branchName: overrides.branchName ?? "PAP-893-workspaces-tab",
+    providerType: overrides.providerType ?? "git_worktree",
+    providerRef: overrides.providerRef ?? null,
+    derivedFromExecutionWorkspaceId: overrides.derivedFromExecutionWorkspaceId ?? null,
+    lastUsedAt: overrides.lastUsedAt ?? new Date("2026-03-26T10:00:00Z"),
+    openedAt: overrides.openedAt ?? new Date("2026-03-26T09:00:00Z"),
+    closedAt: overrides.closedAt ?? null,
+    cleanupEligibleAt: overrides.cleanupEligibleAt ?? null,
+    cleanupReason: overrides.cleanupReason ?? null,
+    metadata: overrides.metadata ?? null,
+    createdAt: overrides.createdAt ?? new Date("2026-03-26T09:00:00Z"),
+    updatedAt: overrides.updatedAt ?? new Date("2026-03-26T09:30:00Z"),
+  };
+}
+
+describe("buildProjectWorkspaceSummaries", () => {
+  const primaryWorkspace = createProjectWorkspace({
+    id: "workspace-default",
+    isPrimary: true,
+    name: "paperclip",
+  });
+  const featureWorkspace = createProjectWorkspace({
+    id: "workspace-feature",
+    name: "feature-checkout",
+    repoRef: "feature/workspaces",
+    updatedAt: new Date("2026-03-25T09:00:00Z"),
+  });
+  const project = {
+    workspaces: [primaryWorkspace, featureWorkspace],
+    primaryWorkspace,
+  } satisfies Pick<Project, "workspaces" | "primaryWorkspace">;
+
+  it("groups isolated execution workspace issues ahead of shared non-primary workspace issues", () => {
+    const summaries = buildProjectWorkspaceSummaries({
+      project,
+      issues: [
+        createIssue({
+          id: "issue-primary",
+          projectWorkspaceId: primaryWorkspace.id,
+          updatedAt: new Date("2026-03-26T08:00:00Z"),
+        }),
+        createIssue({
+          id: "issue-feature-older",
+          projectWorkspaceId: featureWorkspace.id,
+          identifier: "PAP-800",
+          updatedAt: new Date("2026-03-25T10:00:00Z"),
+        }),
+        createIssue({
+          id: "issue-feature-newer",
+          projectWorkspaceId: featureWorkspace.id,
+          identifier: "PAP-801",
+          updatedAt: new Date("2026-03-25T11:00:00Z"),
+        }),
+        createIssue({
+          id: "issue-exec",
+          projectWorkspaceId: primaryWorkspace.id,
+          executionWorkspaceId: "exec-1",
+          identifier: "PAP-893",
+          updatedAt: new Date("2026-03-26T11:00:00Z"),
+        }),
+      ],
+      executionWorkspaces: [
+        createExecutionWorkspace({
+          id: "exec-1",
+          name: "PAP-893",
+          branchName: "PAP-893-workspaces-tab",
+          lastUsedAt: new Date("2026-03-26T10:30:00Z"),
+        }),
+      ],
+    });
+
+    expect(summaries).toHaveLength(2);
+    expect(summaries[0]).toMatchObject({
+      key: "execution:exec-1",
+      kind: "execution_workspace",
+      workspaceName: "PAP-893",
+      branchName: "PAP-893-workspaces-tab",
+      executionWorkspaceId: "exec-1",
+    });
+    expect(summaries[0]?.issues.map((issue) => issue.id)).toEqual(["issue-exec"]);
+
+    expect(summaries[1]).toMatchObject({
+      key: "project:workspace-feature",
+      kind: "project_workspace",
+      workspaceName: "feature-checkout",
+      branchName: "feature/workspaces",
+      projectWorkspaceId: "workspace-feature",
+    });
+    expect(summaries[1]?.issues.map((issue) => issue.id)).toEqual([
+      "issue-feature-newer",
+      "issue-feature-older",
+    ]);
+  });
+
+  it("does not duplicate non-primary workspace issues when an execution workspace owns them", () => {
+    const summaries = buildProjectWorkspaceSummaries({
+      project,
+      issues: [
+        createIssue({
+          id: "issue-exec-derived",
+          projectWorkspaceId: featureWorkspace.id,
+          executionWorkspaceId: "exec-2",
+          updatedAt: new Date("2026-03-26T12:00:00Z"),
+        }),
+      ],
+      executionWorkspaces: [
+        createExecutionWorkspace({
+          id: "exec-2",
+          projectWorkspaceId: featureWorkspace.id,
+          name: "feature-branch run",
+        }),
+      ],
+    });
+
+    expect(summaries).toHaveLength(1);
+    expect(summaries[0]?.key).toBe("execution:exec-2");
+  });
+});

ui/src/lib/project-workspaces-tab.ts

@@ -0,0 +1,108 @@
+import type { ExecutionWorkspace, Issue, Project } from "@paperclipai/shared";
+
+type ProjectWorkspaceLike = Pick<Project, "workspaces" | "primaryWorkspace">;
+
+export interface ProjectWorkspaceSummary {
+  key: string;
+  kind: "execution_workspace" | "project_workspace";
+  workspaceId: string;
+  workspaceName: string;
+  branchName: string | null;
+  lastUpdatedAt: Date;
+  projectWorkspaceId: string | null;
+  executionWorkspaceId: string | null;
+  issues: Issue[];
+}
+
+function toDate(value: Date | string | null | undefined): Date | null {
+  if (!value) return null;
+  const date = value instanceof Date ? value : new Date(value);
+  return Number.isNaN(date.getTime()) ? null : date;
+}
+
+function maxDate(...values: Array<Date | string | null | undefined>): Date {
+  let latest = new Date(0);
+  for (const value of values) {
+    const date = toDate(value);
+    if (date && date.getTime() > latest.getTime()) latest = date;
+  }
+  return latest;
+}
+
+function primaryWorkspaceId(project: ProjectWorkspaceLike): string | null {
+  return project.primaryWorkspace?.id
+    ?? project.workspaces.find((workspace) => workspace.isPrimary)?.id
+    ?? project.workspaces[0]?.id
+    ?? null;
+}
+
+export function buildProjectWorkspaceSummaries(input: {
+  project: ProjectWorkspaceLike;
+  issues: Issue[];
+  executionWorkspaces: ExecutionWorkspace[];
+}): ProjectWorkspaceSummary[] {
+  const primaryId = primaryWorkspaceId(input.project);
+  const executionWorkspacesById = new Map(
+    input.executionWorkspaces.map((workspace) => [workspace.id, workspace] as const),
+  );
+  const projectWorkspacesById = new Map(
+    input.project.workspaces.map((workspace) => [workspace.id, workspace] as const),
+  );
+  const summaries = new Map<string, ProjectWorkspaceSummary>();
+
+  for (const issue of input.issues) {
+    if (issue.executionWorkspaceId) {
+      const executionWorkspace = executionWorkspacesById.get(issue.executionWorkspaceId);
+      if (!executionWorkspace) continue;
+
+      const existing = summaries.get(`execution:${executionWorkspace.id}`);
+      const nextIssues = [...(existing?.issues ?? []), issue].sort(
+        (a, b) => new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime(),
+      );
+
+      summaries.set(`execution:${executionWorkspace.id}`, {
+        key: `execution:${executionWorkspace.id}`,
+        kind: "execution_workspace",
+        workspaceId: executionWorkspace.id,
+        workspaceName: executionWorkspace.name,
+        branchName: executionWorkspace.branchName ?? executionWorkspace.baseRef ?? null,
+        lastUpdatedAt: maxDate(
+          existing?.lastUpdatedAt,
+          executionWorkspace.lastUsedAt,
+          executionWorkspace.updatedAt,
+          issue.updatedAt,
+        ),
+        projectWorkspaceId: executionWorkspace.projectWorkspaceId ?? issue.projectWorkspaceId ?? null,
+        executionWorkspaceId: executionWorkspace.id,
+        issues: nextIssues,
+      });
+      continue;
+    }
+
+    if (!issue.projectWorkspaceId || issue.projectWorkspaceId === primaryId) continue;
+    const projectWorkspace = projectWorkspacesById.get(issue.projectWorkspaceId);
+    if (!projectWorkspace) continue;
+
+    const existing = summaries.get(`project:${projectWorkspace.id}`);
+    const nextIssues = [...(existing?.issues ?? []), issue].sort(
+      (a, b) => new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime(),
+    );
+
+    summaries.set(`project:${projectWorkspace.id}`, {
+      key: `project:${projectWorkspace.id}`,
+      kind: "project_workspace",
+      workspaceId: projectWorkspace.id,
+      workspaceName: projectWorkspace.name,
+      branchName: projectWorkspace.repoRef ?? projectWorkspace.defaultRef ?? null,
+      lastUpdatedAt: maxDate(existing?.lastUpdatedAt, projectWorkspace.updatedAt, issue.updatedAt),
+      projectWorkspaceId: projectWorkspace.id,
+      executionWorkspaceId: null,
+      issues: nextIssues,
+    });
+  }
+
+  return [...summaries.values()].sort((a, b) => {
+    const diff = b.lastUpdatedAt.getTime() - a.lastUpdatedAt.getTime();
+    return diff !== 0 ? diff : a.workspaceName.localeCompare(b.workspaceName);
+  });
+}

ui/src/pages/ProjectDetail.tsx

@@ -1,8 +1,10 @@
 import { useCallback, useEffect, useMemo, useState, useRef } from "react";
-import { useParams, useNavigate, useLocation, Navigate } from "@/lib/router";
+import { Link, useParams, useNavigate, useLocation, Navigate } from "@/lib/router";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
-import { PROJECT_COLORS, isUuidLike, type BudgetPolicySummary } from "@paperclipai/shared";
+import { PROJECT_COLORS, isUuidLike, type BudgetPolicySummary, type ExecutionWorkspace, type Issue, type Project } from "@paperclipai/shared";
 import { budgetsApi } from "../api/budgets";
+import { executionWorkspacesApi } from "../api/execution-workspaces";
+import { instanceSettingsApi } from "../api/instanceSettings";
 import { projectsApi } from "../api/projects";
 import { issuesApi } from "../api/issues";
 import { agentsApi } from "../api/agents";
@@ -20,14 +22,17 @@ import { BudgetPolicyCard } from "../components/BudgetPolicyCard";
 import { IssuesList } from "../components/IssuesList";
 import { PageSkeleton } from "../components/PageSkeleton";
 import { PageTabBar } from "../components/PageTabBar";
-import { projectRouteRef, cn } from "../lib/utils";
+import { buildProjectWorkspaceSummaries } from "../lib/project-workspaces-tab";
+import { projectRouteRef } from "../lib/utils";
+import { timeAgo } from "../lib/timeAgo";
 import { Tabs } from "@/components/ui/tabs";
 import { PluginLauncherOutlet } from "@/plugins/launchers";
 import { PluginSlotMount, PluginSlotOutlet, usePluginSlots } from "@/plugins/slots";
+import { Clock3, GitBranch, Rows3 } from "lucide-react";
 
 /* ── Top-level tab types ── */
 
-type ProjectBaseTab = "overview" | "list" | "configuration" | "budget";
+type ProjectBaseTab = "overview" | "list" | "workspaces" | "configuration" | "budget";
 type ProjectPluginTab = `plugin:${string}`;
 type ProjectTab = ProjectBaseTab | ProjectPluginTab;
 
@@ -44,6 +49,7 @@ function resolveProjectTab(pathname: string, projectId: string): ProjectTab | nu
   if (tab === "configuration") return "configuration";
   if (tab === "budget") return "budget";
   if (tab === "issues") return "list";
+  if (tab === "workspaces") return "workspaces";
   return null;
 }
 
@@ -200,6 +206,88 @@ function ProjectIssuesList({ projectId, companyId }: { projectId: string; compan
   );
 }
 
+function ProjectWorkspacesContent({
+  summaries,
+}: {
+  summaries: ReturnType<typeof buildProjectWorkspaceSummaries>;
+}) {
+  if (summaries.length === 0) {
+    return <p className="text-sm text-muted-foreground">No non-default workspace activity yet.</p>;
+  }
+
+  return (
+    <div className="overflow-hidden rounded-xl border border-border bg-card">
+      {summaries.map((summary) => {
+        const visibleIssues = summary.issues.slice(0, 3);
+        const hiddenIssueCount = Math.max(summary.issues.length - visibleIssues.length, 0);
+
+        return (
+          <div
+            key={summary.key}
+            className="border-b border-border px-4 py-3 last:border-b-0"
+          >
+            <div className="flex items-start justify-between gap-4">
+              <div className="min-w-0 flex-1">
+                <div className="flex min-w-0 flex-wrap items-center gap-2">
+                  {summary.executionWorkspaceId ? (
+                    <Link
+                      to={`/execution-workspaces/${summary.executionWorkspaceId}`}
+                      className="truncate text-sm font-medium hover:underline"
+                    >
+                      {summary.workspaceName}
+                    </Link>
+                  ) : (
+                    <div className="truncate text-sm font-medium">{summary.workspaceName}</div>
+                  )}
+                  <span className="inline-flex items-center rounded-full border border-border bg-background px-2 py-0.5 text-[11px] text-muted-foreground">
+                    {summary.kind === "execution_workspace" ? "Isolated workspace" : "Project workspace"}
+                  </span>
+                </div>
+
+                <div className="mt-1 flex flex-wrap items-center gap-3 text-xs text-muted-foreground">
+                  <span className="inline-flex items-center gap-1">
+                    <GitBranch className="h-3.5 w-3.5" />
+                    <span className="font-mono">{summary.branchName ?? "No branch info"}</span>
+                  </span>
+                  <span className="inline-flex items-center gap-1">
+                    <Rows3 className="h-3.5 w-3.5" />
+                    {summary.issues.length} linked {summary.issues.length === 1 ? "issue" : "issues"}
+                  </span>
+                </div>
+
+                <div className="mt-3 flex flex-wrap gap-2">
+                  {visibleIssues.map((issue) => (
+                    <Link
+                      key={issue.id}
+                      to={`/issues/${issue.identifier ?? issue.id}`}
+                      className="inline-flex max-w-full items-center gap-2 rounded-md border border-border bg-background px-2.5 py-1.5 text-xs transition-colors hover:bg-accent"
+                    >
+                      <span className="shrink-0 font-mono text-[11px] text-muted-foreground">
+                        {issue.identifier ?? issue.id.slice(0, 8)}
+                      </span>
+                      <span className="truncate">{issue.title}</span>
+                    </Link>
+                  ))}
+                  {hiddenIssueCount > 0 ? (
+                    <span className="inline-flex items-center rounded-md border border-dashed border-border px-2.5 py-1.5 text-xs text-muted-foreground">
+                      ... and {hiddenIssueCount} more
+                    </span>
+                  ) : null}
+                </div>
+              </div>
+
+              <div className="inline-flex shrink-0 items-center gap-1 text-xs text-muted-foreground">
+                <Clock3 className="h-3.5 w-3.5" />
+                {timeAgo(summary.lastUpdatedAt)}
+              </div>
+            </div>
+          </div>
+        );
+      })}
+    </div>
+  );
+}
+
 /* ── Main project page ── */
 
 export function ProjectDetail() {
@@ -241,6 +329,10 @@ export function ProjectDetail() {
   const canonicalProjectRef = project ? projectRouteRef(project) : routeProjectRef;
   const projectLookupRef = project?.id ?? routeProjectRef;
   const resolvedCompanyId = project?.companyId ?? selectedCompanyId;
+  const experimentalSettingsQuery = useQuery({
+    queryKey: queryKeys.instance.experimentalSettings,
+    queryFn: () => instanceSettingsApi.getExperimental(),
+  });
   const {
     slots: pluginDetailSlots,
     isLoading: pluginDetailSlotsLoading,
@@ -259,6 +351,39 @@ export function ProjectDetail() {
     [pluginDetailSlots],
   );
   const activePluginTab = pluginTabItems.find((item) => item.value === activeTab) ?? null;
+  const isolatedWorkspacesEnabled = experimentalSettingsQuery.data?.enableIsolatedWorkspaces === true;
+  const workspaceTabProjectId = project?.id ?? null;
+  const { data: workspaceTabIssues = [], isLoading: isWorkspaceTabIssuesLoading, error: workspaceTabIssuesError } = useQuery({
+    queryKey: workspaceTabProjectId && resolvedCompanyId
+      ? queryKeys.issues.listByProject(resolvedCompanyId, workspaceTabProjectId)
+      : ["issues", "__workspace-tab__", "disabled"],
+    queryFn: () => issuesApi.list(resolvedCompanyId!, { projectId: workspaceTabProjectId! }),
+    enabled: Boolean(resolvedCompanyId && workspaceTabProjectId && isolatedWorkspacesEnabled),
+  });
+  const {
+    data: workspaceTabExecutionWorkspaces = [],
+    isLoading: isWorkspaceTabExecutionWorkspacesLoading,
+    error: workspaceTabExecutionWorkspacesError,
+  } = useQuery({
+    queryKey: workspaceTabProjectId && resolvedCompanyId
+      ? queryKeys.executionWorkspaces.list(resolvedCompanyId, { projectId: workspaceTabProjectId })
+      : ["execution-workspaces", "__workspace-tab__", "disabled"],
+    queryFn: () => executionWorkspacesApi.list(resolvedCompanyId!, { projectId: workspaceTabProjectId! }),
+    enabled: Boolean(resolvedCompanyId && workspaceTabProjectId && isolatedWorkspacesEnabled),
+  });
+  const workspaceSummaries = useMemo(() => {
+    if (!project || !isolatedWorkspacesEnabled) return [];
+    return buildProjectWorkspaceSummaries({
+      project,
+      issues: workspaceTabIssues,
+      executionWorkspaces: workspaceTabExecutionWorkspaces,
+    });
+  }, [project, isolatedWorkspacesEnabled, workspaceTabIssues, workspaceTabExecutionWorkspaces]);
+  const showWorkspacesTab = isolatedWorkspacesEnabled && workspaceSummaries.length > 0;
+  const workspaceTabDecisionLoaded =
+    experimentalSettingsQuery.isFetched &&
+    (!isolatedWorkspacesEnabled || (!isWorkspaceTabIssuesLoading && !isWorkspaceTabExecutionWorkspacesLoading));
+  const workspaceTabError = (workspaceTabIssuesError ?? workspaceTabExecutionWorkspacesError) as Error | null;
 
   useEffect(() => {
     if (!project?.companyId || project.companyId === selectedCompanyId) return;
@@ -345,6 +470,10 @@ export function ProjectDetail() {
       navigate(`/projects/${canonicalProjectRef}/budget`, { replace: true });
       return;
     }
+    if (activeTab === "workspaces") {
+      navigate(`/projects/${canonicalProjectRef}/workspaces`, { replace: true });
+      return;
+    }
     if (activeTab === "list") {
       if (filter) {
         navigate(`/projects/${canonicalProjectRef}/issues/${filter}`, { replace: true });
@@ -455,6 +584,10 @@ export function ProjectDetail() {
     return <Navigate to={`/projects/${canonicalProjectRef}/issues`} replace />;
   }
 
+  if (activeTab === "workspaces" && workspaceTabDecisionLoaded && !showWorkspacesTab) {
+    return <Navigate to={`/projects/${canonicalProjectRef}/issues`} replace />;
+  }
+
   // Redirect bare /projects/:id to cached tab or default /issues
   if (routeProjectRef && activeTab === null) {
     let cachedTab: string | null = null;
@@ -470,6 +603,12 @@ export function ProjectDetail() {
     if (cachedTab === "budget") {
       return <Navigate to={`/projects/${canonicalProjectRef}/budget`} replace />;
     }
+    if (cachedTab === "workspaces" && workspaceTabDecisionLoaded && showWorkspacesTab) {
+      return <Navigate to={`/projects/${canonicalProjectRef}/workspaces`} replace />;
+    }
+    if (cachedTab === "workspaces" && !workspaceTabDecisionLoaded) {
+      return <PageSkeleton variant="detail" />;
+    }
     if (isProjectPluginTab(cachedTab)) {
       return <Navigate to={`/projects/${canonicalProjectRef}?tab=${encodeURIComponent(cachedTab)}`} replace />;
     }
@@ -491,6 +630,8 @@ export function ProjectDetail() {
     }
     if (tab === "overview") {
       navigate(`/projects/${canonicalProjectRef}/overview`);
+    } else if (tab === "workspaces") {
+      navigate(`/projects/${canonicalProjectRef}/workspaces`);
     } else if (tab === "budget") {
       navigate(`/projects/${canonicalProjectRef}/budget`);
     } else if (tab === "configuration") {
@@ -561,6 +702,7 @@ export function ProjectDetail() {
           items={[
             { value: "list", label: "Issues" },
             { value: "overview", label: "Overview" },
+            ...(showWorkspacesTab ? [{ value: "workspaces", label: "Workspaces" }] : []),
             { value: "configuration", label: "Configuration" },
             { value: "budget", label: "Budget" },
             ...pluginTabItems.map((item) => ({
@@ -589,6 +731,18 @@ export function ProjectDetail() {
         <ProjectIssuesList projectId={project.id} companyId={resolvedCompanyId} />
       )}
 
+      {activeTab === "workspaces" ? (
+        workspaceTabDecisionLoaded ? (
+          workspaceTabError ? (
+            <p className="text-sm text-destructive">{workspaceTabError.message}</p>
+          ) : (
+            <ProjectWorkspacesContent summaries={workspaceSummaries} />
+          )
+        ) : (
+          <p className="text-sm text-muted-foreground">Loading workspaces...</p>
+        )
+      ) : null}
+
       {activeTab === "configuration" && (
         <div className="max-w-4xl">
           <ProjectProperties