feat(frontend): migrate server-state from Zustand to TanStack Query + perf optimizations | ENG-202 & ENG-204 (#298)

* feat(frontend): add TanStack Query foundation and query hooks for all domains

- Install @tanstack/react-query, add QueryClient and QueryClientProvider
- Create org-scoped query key factories in queryKeys.ts
- Create queryOptions() factories for execution data in executionQueryOptions.ts
- Add query hooks for all server-state domains: runs, workflows, executions,
  components, integrations, MCP groups/servers, schedules, secrets, webhooks,
  API keys, artifacts, and human input
- Export TerminalChunkResponse from api.ts for queryOptions type inference
- Add mcpGroupsApi service for N+1 batch endpoints

Signed-off-by: Aseem Shrey <LuD1161@users.noreply.github.com>

* refactor(frontend): migrate all consumers to TanStack Query and delete Zustand stores

- Migrate all pages, components, and features from Zustand stores to query hooks
- Route execution/timeline Zustand stores through queryOptions() factories
- Delete 11 Zustand stores (apiKey, artifact, component, integration, mcpGroup,
  mcpServer, run, schedule, secret, webhook) and their tests
- Update remaining tests to work with TanStack Query patterns
- Fix N+1 query patterns on WorkflowList and MCP Library pages (backend batch endpoints)

Signed-off-by: Aseem Shrey <LuD1161@users.noreply.github.com>

* perf(frontend): add idle-time prefetching, bundle optimization, and backend batch endpoints

- Add idle-time prefetching for components and workflows via requestIdleCallback
- Optimize bundle with manual chunks, font preloading, and lazy route loading
- Add backend batch endpoints for workflow summaries and MCP group server counts
- Gate prefetch on auth state and align cache shapes to prevent mismatches
- Add VITE_DISABLE_DEVTOOLS env var

Signed-off-by: Aseem Shrey <LuD1161@users.noreply.github.com>

* docs(frontend): add performance guidelines, state management docs, and load testing audit

- Add frontend/docs/performance.md with query hook and rendering guidelines
- Update frontend/docs/state.md with TanStack Query migration patterns
- Add load testing audit report (2026-02-17)
- Add performance-review skill and rename load-audit to stress-test-frontend
- Update AGENTS.md with TanStack Query enforcement rules
- Update READMEs for hooks and stores

Signed-off-by: Aseem Shrey <LuD1161@users.noreply.github.com>

---------

Signed-off-by: Aseem Shrey <LuD1161@users.noreply.github.com>
Co-authored-by: Aseem Shrey <LuD1161@users.noreply.github.com>

Author: LuD1161

.claude/skills/performance-review/SKILL.md

@@ -0,0 +1,91 @@
+---
+name: performance-review
+description: Review frontend code changes for performance anti-patterns and guideline compliance. Checks query hooks, stale times, bundle impact, rendering patterns, and Zustand selectors.
+user_invocable: true
+---
+
+# Frontend Performance Review
+
+**Reference:** `frontend/docs/performance.md`
+
+---
+
+## When to Invoke
+
+- Before submitting a PR that adds or modifies query hooks, page components, Zustand stores, or real-time features
+- When the user asks for a "performance review" or "perf check"
+- As part of the component-development workflow for new pages
+
+## Agent Instructions
+
+When invoked, perform the following checks in order. Report PASS/FAIL/WARN for each. Group failures by severity: **CRITICAL** (must fix before merge), **WARNING** (should fix), **INFO** (consider).
+
+### Step 1: Identify Scope
+
+Read the diff or the files specified by the user. If no files specified, use `git diff --name-only` to find changed frontend files. Identify which categories apply: query hooks, page routes, stores, real-time, bundle.
+
+### Step 2: Query Hook Checks
+
+1. Search for `useState` + `useEffect` + `api.` within 20 lines of each other in changed files. If found: **CRITICAL** — should be a TanStack Query hook.
+2. Check that new `useQuery` calls reference a key from `queryKeys.ts`, not an inline array. If inline: **CRITICAL**.
+3. Check that new query hook files are named `use<Domain>Queries.ts` and placed in `src/hooks/queries/`. If misplaced: **WARNING**.
+4. Check that `useMutation` calls include `onSuccess` with `queryClient.invalidateQueries()`. If missing: **WARNING**.
+5. Check for `skipToken` usage on conditional queries vs. `enabled: false`. Flag `enabled: false` without `skipToken` as **WARNING**.
+
+### Step 3: Stale Time Audit
+
+1. For each new `useQuery`, check if `staleTime` is set explicitly or inherits the 30s default appropriately.
+2. Cross-reference the data type: if the query fetches components, templates, or providers — flag missing `staleTime: Infinity` as **CRITICAL**.
+3. For execution queries, verify they use `executionQueryOptions.ts` factories rather than inline values. Flag inconsistency as **WARNING**.
+4. For queries on terminal runs, verify `terminalStaleTime()` is used rather than a hardcoded number.
+
+### Step 4: Bundle Impact
+
+1. For each new page added to `App.tsx`: verify it uses `React.lazy(() => import(...))`. Static imports are **CRITICAL**.
+2. Verify new sidebar pages are added to `routePrefetchMap` in `src/lib/prefetch-routes.ts`. Missing entry is **WARNING**.
+3. If a new conditionally-visible component imports a library > 100KB (check for `@xterm`, `posthog-js`, `lucide-react` barrel imports): flag as **WARNING** — consider deferred load pattern.
+
+### Step 5: Rendering Checks
+
+1. Search for `const [*, set*] = useState` followed by `set*` inside a `useEffect` that references query data — **CRITICAL** (should use `useMemo`).
+2. Look for derived data calculations inline in JSX without `useMemo` involving array operations (filter, sort, reduce) — **WARNING**.
+3. Check for `React.memo` usage on new components in `timeline/` or `workflow/` directories that re-render frequently — **INFO** if missing.
+
+### Step 6: Zustand Store Checks
+
+1. Search for `const store = use<X>Store()` or destructuring from `use<X>Store()` without a selector — full store subscription. **WARNING**.
+2. For new stores using `persist`, verify `partialize` is present. Missing is **WARNING**.
+3. For new `persist` stores, verify action functions are excluded from `partialize`.
+
+### Step 7: Generate Report
+
+Format the output as follows:
+
+```
+## Performance Review: [description of scope]
+
+### Critical (must fix before merge)
+- [file:line] Description of issue. See: performance.md § [section]
+
+### Warnings (should fix)
+- [file:line] Description of issue. See: performance.md § [section]
+
+### Info (consider)
+- [file:line] Description. See: performance.md § [section]
+
+### Passed Checks
+- [n] query hooks using TanStack Query correctly
+- [n] page routes using React.lazy
+- [n] Zustand selectors properly scoped
+- staleTime: appropriate tiers applied
+
+### Summary
+[1-2 sentences on overall performance hygiene of the change]
+```
+
+## Rules
+
+- This is a **review only** — do NOT make code changes unless the user explicitly asks
+- Always cite the file and line number for each finding
+- Always reference `frontend/docs/performance.md` for the relevant pattern section
+- If no frontend files are in the diff, report "No frontend changes detected" and exit

.claude/skills/load-audit/SKILL.md …ude/skills/stress-test-frontend/SKILL.md.claude/skills/load-audit/SKILL.md renamed to .claude/skills/stress-test-frontend/SKILL.md .claude/skills/load-audit/SKILL.md renamed to .claude/skills/stress-test-frontend/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: load-audit
+name: stress-test-frontend
 description: Run a frontend load testing audit. Seeds data, tests all pages via Chrome DevTools MCP, records network calls, TanStack queries, DOM sizes, and generates a timestamped report.
 user_invocable: true
 ---
@@ -13,7 +13,7 @@ user_invocable: true
 
 ## Agent Instructions
 
-When the user invokes `/load-audit`, perform a full frontend load testing audit:
+When the user invokes `/stress-test-frontend`, perform a full frontend load testing audit:
 
 ### 1. Setup
 

AGENTS.md

@@ -98,6 +98,35 @@ bun --cwd backend run db:studio            # View data
 4. **E2E Tests**: Mandatory for significant features. Place in `e2e-tests/` folder.
 5. **GitHub CLI**: Use `gh` for all GitHub operations (issues, PRs, actions, releases). Never use browser automation for GitHub tasks.
 
+### Frontend: Read Before Writing Code
+
+Before writing ANY frontend code that fetches data or adds a page, you MUST read these files first:
+
+1. `frontend/docs/state.md` — Decision guide: TanStack Query vs Zustand, hook patterns, anti-patterns
+2. `frontend/docs/performance.md` — Stale time tiers, bundle splitting, prefetch patterns, query key architecture
+3. `frontend/src/lib/queryKeys.ts` — Existing query key factories (add new keys here, never inline)
+4. Browse `frontend/src/hooks/queries/` — Follow existing hook naming conventions (`use<Domain>Queries.ts`)
+
+### Frontend Data Fetching (Mandatory)
+
+6. **All API data must use TanStack Query hooks** in `frontend/src/hooks/queries/`. Never use `useState` + `useEffect` to fetch backend data — this is the single most important frontend rule.
+7. **Query keys** go in `frontend/src/lib/queryKeys.ts` (org-scoped, factory functions).
+8. **After mutations**, invalidate the relevant query cache via `queryClient.invalidateQueries()` — do not manually update local state.
+9. **Derive data** from query results using `useMemo`, not by copying into separate `useState`.
+10. **Zustand stores** are for client-only UI state (canvas, timeline, auth). Never store API data in Zustand.
+
+See `frontend/docs/state.md` for patterns, anti-patterns, and the full decision guide.
+
+### Frontend Performance (Mandatory)
+
+See `frontend/docs/performance.md` for the complete reference with code examples.
+
+11. **Every new page must use `React.lazy()`** in `App.tsx`. Add the route to `routePrefetchMap` in `src/lib/prefetch-routes.ts`.
+12. **Set `staleTime: Infinity` for static/reference data** (components, templates, providers). The 30s default is wrong for them.
+13. **Use `skipToken` for conditional queries** instead of `enabled: false` alone. See `useRunQueries.ts`.
+14. **Granular Zustand selectors**: `useStore((s) => s.field)`, never `const store = useStore()`.
+15. **No N+1 queries**: never call a query hook inside `.map()`. Use a batched endpoint (see `useMcpGroupsWithServers`).
+
 ---
 
 ## Architecture
@@ -140,6 +169,16 @@ When tasks match a skill, load it: `cat .claude/skills/<name>/SKILL.md`
 <description>Creating components (inline/docker). Dynamic ports, retry policies, PTY patterns, IsolatedContainerVolume.</description>
 <location>project</location>
 </skill>
+<skill>
+<name>performance-review</name>
+<description>Review code changes for frontend performance anti-patterns. Checks stale times, bundle splitting, Zustand selectors, N+1 queries, and React rendering.</description>
+<location>project</location>
+</skill>
+<skill>
+<name>stress-test-frontend</name>
+<description>Run a frontend load testing audit. Seeds data, tests all pages via Chrome DevTools MCP, records network calls, TanStack queries, DOM sizes, and generates a timestamped report.</description>
+<location>project</location>
+</skill>
 </available_skills>
 
 </skills_system>

backend/src/mcp-groups/mcp-groups.controller.ts

@@ -45,9 +45,16 @@ export class McpGroupsController {
   @Get()
   @ApiOperation({ summary: 'List all MCP groups' })
   @ApiQuery({ name: 'enabled', required: false, type: Boolean })
+  @ApiQuery({ name: 'includeServers', required: false, type: Boolean })
   @ApiOkResponse({ type: [McpGroupResponse] })
-  async listGroups(@Query('enabled') enabled?: string): Promise<McpGroupResponse[]> {
+  async listGroups(
+    @Query('enabled') enabled?: string,
+    @Query('includeServers') includeServers?: string,
+  ): Promise<McpGroupResponse[]> {
     const enabledOnly = enabled === 'true';
+    if (includeServers === 'true') {
+      return this.mcpGroupsService.listGroupsWithServers(enabledOnly);
+    }
     return this.mcpGroupsService.listGroups(enabledOnly);
   }
 

backend/src/mcp-groups/mcp-groups.repository.ts

@@ -123,6 +123,60 @@ export class McpGroupsRepository {
 
   // Group-Server relationship methods
 
+  async findAllServersGrouped(): Promise<
+    Map<
+      string,
+      (McpServerRecord & { recommended: boolean; defaultSelected: boolean; toolCount: number })[]
+    >
+  > {
+    const query = sql`
+      SELECT
+        gs.group_id,
+        s.id,
+        s.name,
+        s.description,
+        s.transport_type,
+        s.endpoint,
+        s.command,
+        s.args,
+        s.headers,
+        s.enabled,
+        s.health_check_url,
+        s.last_health_check,
+        s.last_health_status,
+        s.group_id AS server_group_id,
+        s.organization_id,
+        s.created_by,
+        s.created_at,
+        s.updated_at,
+        gs.recommended,
+        gs.default_selected,
+        COALESCE(tc.tool_count, 0) as tool_count
+      FROM mcp_group_servers gs
+      INNER JOIN mcp_servers s ON gs.server_id = s.id
+      LEFT JOIN (
+        SELECT server_id, COUNT(id) as tool_count
+        FROM mcp_server_tools
+        GROUP BY server_id
+      ) tc ON tc.server_id = s.id
+      ORDER BY gs.group_id, CASE WHEN gs.recommended THEN 0 ELSE 1 END ASC, s.name
+    `;
+
+    const result = await this.db.execute(query);
+    const grouped = new Map<
+      string,
+      (McpServerRecord & { recommended: boolean; defaultSelected: boolean; toolCount: number })[]
+    >();
+    for (const row of result.rows as any[]) {
+      const groupId = row.group_id;
+      if (!grouped.has(groupId)) {
+        grouped.set(groupId, []);
+      }
+      grouped.get(groupId)!.push(row);
+    }
+    return grouped;
+  }
+
   async findServersByGroup(
     groupId: string,
   ): Promise<

backend/src/mcp-groups/mcp-groups.service.ts

@@ -106,6 +106,19 @@ export class McpGroupsService implements OnModuleInit {
     return groups.map((g) => this.mapGroupToResponse(g));
   }
 
+  async listGroupsWithServers(
+    enabledOnly = false,
+  ): Promise<(McpGroupResponse & { servers: McpGroupServerResponse[] })[]> {
+    const [groups, serversMap] = await Promise.all([
+      this.repository.findAll(enabledOnly ? { enabled: true } : {}),
+      this.repository.findAllServersGrouped(),
+    ]);
+    return groups.map((g) => ({
+      ...this.mapGroupToResponse(g),
+      servers: (serversMap.get(g.id) ?? []).map((s) => this.mapGroupServerToResponse(s)),
+    }));
+  }
+
   listTemplates(): GroupTemplateDto[] {
     return this.seedingService.getAllTemplates();
   }

backend/src/workflows/repository/workflow.repository.ts

@@ -16,6 +16,7 @@ export interface WorkflowSummaryRecord {
   description: string | null;
   organizationId: string | null;
   lastRun: Date | null;
+  latestRunStatus: string | null;
   runCount: number;
   nodeCount: number;
   createdAt: Date;
@@ -152,6 +153,12 @@ export class WorkflowRepository {
       description: workflowsTable.description,
       organizationId: workflowsTable.organizationId,
       lastRun: workflowsTable.lastRun,
+      latestRunStatus: sql<string | null>`(
+        SELECT wr.status FROM workflow_runs wr
+        WHERE wr.workflow_id = ${workflowsTable.id}
+        ORDER BY wr.created_at DESC
+        LIMIT 1
+      )`.as('latest_run_status'),
       runCount: workflowsTable.runCount,
       nodeCount: sql<number>`coalesce(jsonb_array_length(${workflowsTable.graph}->'nodes'), 0)`.as(
         'node_count',

backend/src/workflows/workflows.service.ts

@@ -54,6 +54,7 @@ export interface WorkflowSummaryResponse {
   description: string | null;
   organizationId: string | null;
   lastRun: string | null;
+  latestRunStatus: string | null;
   runCount: number;
   nodeCount: number;
   createdAt: string;
@@ -560,6 +561,7 @@ export class WorkflowsService {
     return records.map((record) => ({
       ...record,
       lastRun: record.lastRun?.toISOString() ?? null,
+      latestRunStatus: record.latestRunStatus ?? null,
       createdAt: record.createdAt.toISOString(),
       updatedAt: record.updatedAt.toISOString(),
     }));

bun.lock

@@ -26,3 +26,7 @@ VITE_LOGO_DEV_PUBLIC_KEY=
 # Leave empty to hide Dashboards navigation link
 # For dev/prod: http://localhost/analytics (nginx in dev/prod)
 VITE_OPENSEARCH_DASHBOARDS_URL=http://localhost/analytics
+
+# Dev Tools
+# Set to 'true' to hide TanStack Query devtools in development mode
+# VITE_DISABLE_DEVTOOLS=true