diff --git a/api/server/controllers/ModelController.js b/api/server/controllers/ModelController.js
index 805d9eef27..1741d3f6b1 100644
--- a/api/server/controllers/ModelController.js
+++ b/api/server/controllers/ModelController.js
@@ -1,5 +1,5 @@
-const { logger } = require('@librechat/data-schemas');
 const { CacheKeys } = require('librechat-data-provider');
+const { logger, scopedCacheKey } = require('@librechat/data-schemas');
 const { loadDefaultModels, loadConfigModels } = require('~/server/services/Config');
 const { getLogStores } = require('~/cache');
 
@@ -9,7 +9,8 @@ const { getLogStores } = require('~/cache');
  */
 const getModelsConfig = async (req) => {
   const cache = getLogStores(CacheKeys.CONFIG_STORE);
-  let modelsConfig = await cache.get(CacheKeys.MODELS_CONFIG);
+  const cacheKey = scopedCacheKey(CacheKeys.MODELS_CONFIG);
+  let modelsConfig = await cache.get(cacheKey);
   if (!modelsConfig) {
     modelsConfig = await loadModels(req);
   }
@@ -24,7 +25,8 @@ const getModelsConfig = async (req) => {
  */
 async function loadModels(req) {
   const cache = getLogStores(CacheKeys.CONFIG_STORE);
-  const cachedModelsConfig = await cache.get(CacheKeys.MODELS_CONFIG);
+  const cacheKey = scopedCacheKey(CacheKeys.MODELS_CONFIG);
+  const cachedModelsConfig = await cache.get(cacheKey);
   if (cachedModelsConfig) {
     return cachedModelsConfig;
   }
@@ -33,7 +35,7 @@ async function loadModels(req) {
 
   const modelConfig = { ...defaultModelsConfig, ...customModelsConfig };
 
-  await cache.set(CacheKeys.MODELS_CONFIG, modelConfig);
+  await cache.set(cacheKey, modelConfig);
   return modelConfig;
 }
 
diff --git a/api/server/controllers/PluginController.js b/api/server/controllers/PluginController.js
index 14dd284c30..7c47fe4d57 100644
--- a/api/server/controllers/PluginController.js
+++ b/api/server/controllers/PluginController.js
@@ -1,5 +1,5 @@
-const { logger } = require('@librechat/data-schemas');
 const { CacheKeys } = require('librechat-data-provider');
+const { logger, scopedCacheKey } = require('@librechat/data-schemas');
 const { getToolkitKey, checkPluginAuth, filterUniquePlugins } = require('@librechat/api');
 const { getCachedTools, setCachedTools } = require('~/server/services/Config');
 const { availableTools, toolkits } = require('~/app/clients/tools');
@@ -9,7 +9,8 @@ const { getLogStores } = require('~/cache');
 const getAvailablePluginsController = async (req, res) => {
   try {
     const cache = getLogStores(CacheKeys.TOOL_CACHE);
-    const cachedPlugins = await cache.get(CacheKeys.PLUGINS);
+    const pluginsCacheKey = scopedCacheKey(CacheKeys.PLUGINS);
+    const cachedPlugins = await cache.get(pluginsCacheKey);
     if (cachedPlugins) {
       res.status(200).json(cachedPlugins);
       return;
@@ -37,7 +38,7 @@ const getAvailablePluginsController = async (req, res) => {
       plugins = plugins.filter((plugin) => !filteredTools.includes(plugin.pluginKey));
     }
 
-    await cache.set(CacheKeys.PLUGINS, plugins);
+    await cache.set(pluginsCacheKey, plugins);
     res.status(200).json(plugins);
   } catch (error) {
     res.status(500).json({ message: error.message });
@@ -64,7 +65,8 @@ const getAvailableTools = async (req, res) => {
       return res.status(401).json({ message: 'Unauthorized' });
     }
     const cache = getLogStores(CacheKeys.TOOL_CACHE);
-    const cachedToolsArray = await cache.get(CacheKeys.TOOLS);
+    const toolsCacheKey = scopedCacheKey(CacheKeys.TOOLS);
+    const cachedToolsArray = await cache.get(toolsCacheKey);
 
     const appConfig =
       req.config ?? (await getAppConfig({ role: req.user?.role, tenantId: req.user?.tenantId }));
@@ -115,7 +117,7 @@ const getAvailableTools = async (req, res) => {
     }
 
     const finalTools = filterUniquePlugins(toolsOutput);
-    await cache.set(CacheKeys.TOOLS, finalTools);
+    await cache.set(toolsCacheKey, finalTools);
 
     res.status(200).json(finalTools);
   } catch (error) {
diff --git a/api/server/controllers/PluginController.spec.js b/api/server/controllers/PluginController.spec.js
index 06a51a3bd6..fdbc2401ce 100644
--- a/api/server/controllers/PluginController.spec.js
+++ b/api/server/controllers/PluginController.spec.js
@@ -8,6 +8,7 @@ jest.mock('@librechat/data-schemas', () => ({
     error: jest.fn(),
     warn: jest.fn(),
   },
+  scopedCacheKey: jest.fn((key) => key),
 }));
 
 jest.mock('~/server/services/Config', () => ({
diff --git a/api/server/index.js b/api/server/index.js
index 813b453468..4b919b1ceb 100644
--- a/api/server/index.js
+++ b/api/server/index.js
@@ -21,6 +21,7 @@ const {
   createStreamServices,
   initializeFileStorage,
   updateInterfacePermissions,
+  preAuthTenantMiddleware,
 } = require('@librechat/api');
 const { connectDb, indexSync } = require('~/db');
 const initializeOAuthReconnectManager = require('./services/initializeOAuthReconnectManager');
@@ -59,7 +60,14 @@ const startServer = async () => {
   app.disable('x-powered-by');
   app.set('trust proxy', trusted_proxy);
 
-  await seedDatabase();
+  if (isEnabled(process.env.TENANT_ISOLATION_STRICT)) {
+    logger.warn(
+      '[Security] TENANT_ISOLATION_STRICT is active. Ensure your reverse proxy strips or sets ' +
+        'the X-Tenant-Id header — untrusted clients must not be able to set it directly.',
+    );
+  }
+
+  await runAsSystem(seedDatabase);
   const appConfig = await getAppConfig({ baseOnly: true });
   initializeFileStorage(appConfig);
   await runAsSystem(async () => {
@@ -139,9 +147,11 @@ const startServer = async () => {
   /* Per-request capability cache — must be registered before any route that calls hasCapability */
   app.use(capabilityContextMiddleware);
 
-  app.use('/oauth', routes.oauth);
+  /* Pre-auth tenant context for unauthenticated routes that need tenant scoping.
+   * The reverse proxy / auth gateway sets `X-Tenant-Id` header for multi-tenant deployments. */
+  app.use('/oauth', preAuthTenantMiddleware, routes.oauth);
   /* API Endpoints */
-  app.use('/api/auth', routes.auth);
+  app.use('/api/auth', preAuthTenantMiddleware, routes.auth);
   app.use('/api/admin', routes.adminAuth);
   app.use('/api/admin/config', routes.adminConfig);
   app.use('/api/admin/groups', routes.adminGroups);
@@ -159,11 +169,11 @@ const startServer = async () => {
   app.use('/api/endpoints', routes.endpoints);
   app.use('/api/balance', routes.balance);
   app.use('/api/models', routes.models);
-  app.use('/api/config', routes.config);
+  app.use('/api/config', preAuthTenantMiddleware, routes.config);
   app.use('/api/assistants', routes.assistants);
   app.use('/api/files', await routes.files.initialize());
   app.use('/images/', createValidateImageRequest(appConfig.secureImageLinks), routes.staticRoute);
-  app.use('/api/share', routes.share);
+  app.use('/api/share', preAuthTenantMiddleware, routes.share);
   app.use('/api/roles', routes.roles);
   app.use('/api/agents', routes.agents);
   app.use('/api/banner', routes.banner);
diff --git a/api/server/middleware/optionalJwtAuth.js b/api/server/middleware/optionalJwtAuth.js
index 2f59fdda4a..d46478d36e 100644
--- a/api/server/middleware/optionalJwtAuth.js
+++ b/api/server/middleware/optionalJwtAuth.js
@@ -1,9 +1,10 @@
 const cookies = require('cookie');
 const passport = require('passport');
-const { isEnabled } = require('@librechat/api');
+const { isEnabled, tenantContextMiddleware } = require('@librechat/api');
 
 // This middleware does not require authentication,
-// but if the user is authenticated, it will set the user object.
+// but if the user is authenticated, it will set the user object
+// and establish tenant ALS context.
 const optionalJwtAuth = (req, res, next) => {
   const cookieHeader = req.headers.cookie;
   const tokenProvider = cookieHeader ? cookies.parse(cookieHeader).token_provider : null;
@@ -13,6 +14,7 @@ const optionalJwtAuth = (req, res, next) => {
     }
     if (user) {
       req.user = user;
+      return tenantContextMiddleware(req, res, next);
     }
     next();
   };
diff --git a/api/server/routes/agents/__tests__/streamTenant.spec.js b/api/server/routes/agents/__tests__/streamTenant.spec.js
new file mode 100644
index 0000000000..1f89953186
--- /dev/null
+++ b/api/server/routes/agents/__tests__/streamTenant.spec.js
@@ -0,0 +1,186 @@
+const express = require('express');
+const request = require('supertest');
+
+const mockGenerationJobManager = {
+  getJob: jest.fn(),
+  subscribe: jest.fn(),
+  getResumeState: jest.fn(),
+  abortJob: jest.fn(),
+  getActiveJobIdsForUser: jest.fn().mockResolvedValue([]),
+};
+
+jest.mock('@librechat/data-schemas', () => ({
+  ...jest.requireActual('@librechat/data-schemas'),
+  logger: {
+    debug: jest.fn(),
+    warn: jest.fn(),
+    error: jest.fn(),
+    info: jest.fn(),
+  },
+}));
+
+jest.mock('@librechat/api', () => ({
+  ...jest.requireActual('@librechat/api'),
+  isEnabled: jest.fn().mockReturnValue(false),
+  GenerationJobManager: mockGenerationJobManager,
+}));
+
+jest.mock('~/models', () => ({
+  saveMessage: jest.fn(),
+}));
+
+let mockUserId = 'user-123';
+let mockTenantId;
+
+jest.mock('~/server/middleware', () => ({
+  uaParser: (req, res, next) => next(),
+  checkBan: (req, res, next) => next(),
+  requireJwtAuth: (req, res, next) => {
+    req.user = { id: mockUserId, tenantId: mockTenantId };
+    next();
+  },
+  messageIpLimiter: (req, res, next) => next(),
+  configMiddleware: (req, res, next) => next(),
+  messageUserLimiter: (req, res, next) => next(),
+}));
+
+jest.mock('~/server/routes/agents/chat', () => require('express').Router());
+jest.mock('~/server/routes/agents/v1', () => ({
+  v1: require('express').Router(),
+}));
+jest.mock('~/server/routes/agents/openai', () => require('express').Router());
+jest.mock('~/server/routes/agents/responses', () => require('express').Router());
+
+const agentsRouter = require('../index');
+const app = express();
+app.use(express.json());
+app.use('/agents', agentsRouter);
+
+function mockSubscribeSuccess() {
+  mockGenerationJobManager.subscribe.mockImplementation((_streamId, _writeEvent, onDone) => {
+    process.nextTick(() => onDone({ done: true }));
+    return { unsubscribe: jest.fn() };
+  });
+}
+
+describe('SSE stream tenant isolation', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockUserId = 'user-123';
+    mockTenantId = undefined;
+  });
+
+  describe('GET /chat/stream/:streamId', () => {
+    it('returns 403 when a user from a different tenant accesses a stream', async () => {
+      mockUserId = 'user-456';
+      mockTenantId = 'tenant-b';
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-456', tenantId: 'tenant-a' },
+        status: 'running',
+      });
+
+      const res = await request(app).get('/agents/chat/stream/stream-123');
+      expect(res.status).toBe(403);
+      expect(res.body.error).toBe('Unauthorized');
+    });
+
+    it('returns 404 when stream does not exist', async () => {
+      mockGenerationJobManager.getJob.mockResolvedValue(null);
+
+      const res = await request(app).get('/agents/chat/stream/nonexistent');
+      expect(res.status).toBe(404);
+    });
+
+    it('proceeds past tenant guard when tenant matches', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = 'tenant-a';
+      mockSubscribeSuccess();
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123', tenantId: 'tenant-a' },
+        status: 'running',
+      });
+
+      const res = await request(app).get('/agents/chat/stream/stream-123');
+      expect(res.status).toBe(200);
+      expect(mockGenerationJobManager.subscribe).toHaveBeenCalledTimes(1);
+    });
+
+    it('proceeds past tenant guard when job has no tenantId (single-tenant mode)', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = undefined;
+      mockSubscribeSuccess();
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123' },
+        status: 'running',
+      });
+
+      const res = await request(app).get('/agents/chat/stream/stream-123');
+      expect(res.status).toBe(200);
+      expect(mockGenerationJobManager.subscribe).toHaveBeenCalledTimes(1);
+    });
+
+    it('returns 403 when job has tenantId but user has no tenantId', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = undefined;
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123', tenantId: 'some-tenant' },
+        status: 'running',
+      });
+
+      const res = await request(app).get('/agents/chat/stream/stream-123');
+      expect(res.status).toBe(403);
+    });
+  });
+
+  describe('GET /chat/status/:conversationId', () => {
+    it('returns 403 when tenant does not match', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = 'tenant-b';
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123', tenantId: 'tenant-a' },
+        status: 'running',
+      });
+
+      const res = await request(app).get('/agents/chat/status/conv-123');
+      expect(res.status).toBe(403);
+      expect(res.body.error).toBe('Unauthorized');
+    });
+
+    it('returns status when tenant matches', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = 'tenant-a';
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123', tenantId: 'tenant-a' },
+        status: 'running',
+        createdAt: Date.now(),
+      });
+      mockGenerationJobManager.getResumeState.mockResolvedValue(null);
+
+      const res = await request(app).get('/agents/chat/status/conv-123');
+      expect(res.status).toBe(200);
+      expect(res.body.active).toBe(true);
+    });
+  });
+
+  describe('POST /chat/abort', () => {
+    it('returns 403 when tenant does not match', async () => {
+      mockUserId = 'user-123';
+      mockTenantId = 'tenant-b';
+
+      mockGenerationJobManager.getJob.mockResolvedValue({
+        metadata: { userId: 'user-123', tenantId: 'tenant-a' },
+        status: 'running',
+      });
+
+      const res = await request(app).post('/agents/chat/abort').send({ streamId: 'stream-123' });
+      expect(res.status).toBe(403);
+      expect(res.body.error).toBe('Unauthorized');
+    });
+  });
+});
diff --git a/api/server/routes/agents/index.js b/api/server/routes/agents/index.js
index 86966a3f3e..eb42046bed 100644
--- a/api/server/routes/agents/index.js
+++ b/api/server/routes/agents/index.js
@@ -17,6 +17,11 @@ const chat = require('./chat');
 
 const { LIMIT_MESSAGE_IP, LIMIT_MESSAGE_USER } = process.env ?? {};
 
+/** Untenanted jobs (pre-multi-tenancy) remain accessible if the userId check passes. */
+function hasTenantMismatch(job, user) {
+  return job.metadata?.tenantId != null && job.metadata.tenantId !== user.tenantId;
+}
+
 const router = express.Router();
 
 /**
@@ -67,6 +72,10 @@ router.get('/chat/stream/:streamId', async (req, res) => {
     return res.status(403).json({ error: 'Unauthorized' });
   }
 
+  if (hasTenantMismatch(job, req.user)) {
+    return res.status(403).json({ error: 'Unauthorized' });
+  }
+
   res.setHeader('Content-Encoding', 'identity');
   res.setHeader('Content-Type', 'text/event-stream');
   res.setHeader('Cache-Control', 'no-cache, no-transform');
@@ -150,7 +159,10 @@ router.get('/chat/stream/:streamId', async (req, res) => {
  * @returns { activeJobIds: string[] }
  */
 router.get('/chat/active', async (req, res) => {
-  const activeJobIds = await GenerationJobManager.getActiveJobIdsForUser(req.user.id);
+  const activeJobIds = await GenerationJobManager.getActiveJobIdsForUser(
+    req.user.id,
+    req.user.tenantId,
+  );
   res.json({ activeJobIds });
 });
 
@@ -174,6 +186,10 @@ router.get('/chat/status/:conversationId', async (req, res) => {
     return res.status(403).json({ error: 'Unauthorized' });
   }
 
+  if (hasTenantMismatch(job, req.user)) {
+    return res.status(403).json({ error: 'Unauthorized' });
+  }
+
   // Get resume state which contains aggregatedContent
   // Avoid calling both getStreamInfo and getResumeState (both fetch content)
   const resumeState = await GenerationJobManager.getResumeState(conversationId);
@@ -213,7 +229,10 @@ router.post('/chat/abort', async (req, res) => {
   // This handles the case where frontend sends "new" but job was created with a UUID
   if (!job && userId) {
     logger.debug(`[AgentStream] Job not found by ID, checking active jobs for user: ${userId}`);
-    const activeJobIds = await GenerationJobManager.getActiveJobIdsForUser(userId);
+    const activeJobIds = await GenerationJobManager.getActiveJobIdsForUser(
+      userId,
+      req.user.tenantId,
+    );
     if (activeJobIds.length > 0) {
       // Abort the most recent active job for this user
       jobStreamId = activeJobIds[0];
@@ -230,6 +249,10 @@ router.post('/chat/abort', async (req, res) => {
       return res.status(403).json({ error: 'Unauthorized' });
     }
 
+    if (hasTenantMismatch(job, req.user)) {
+      return res.status(403).json({ error: 'Unauthorized' });
+    }
+
     logger.debug(`[AgentStream] Job found, aborting: ${jobStreamId}`);
     const abortResult = await GenerationJobManager.abortJob(jobStreamId);
     logger.debug(`[AgentStream] Job aborted successfully: ${jobStreamId}`, {
diff --git a/api/server/routes/config.js b/api/server/routes/config.js
index 0a68ccba4f..8caa180854 100644
--- a/api/server/routes/config.js
+++ b/api/server/routes/config.js
@@ -1,7 +1,7 @@
 const express = require('express');
-const { logger } = require('@librechat/data-schemas');
 const { isEnabled, getBalanceConfig } = require('@librechat/api');
 const { CacheKeys, defaultSocialLogins } = require('librechat-data-provider');
+const { logger, getTenantId, scopedCacheKey } = require('@librechat/data-schemas');
 const { getLdapConfig } = require('~/server/services/Config/ldap');
 const { getAppConfig } = require('~/server/services/Config/app');
 const { getLogStores } = require('~/cache');
@@ -23,7 +23,8 @@ const openidReuseTokens = isEnabled(process.env.OPENID_REUSE_TOKENS);
 router.get('/', async function (req, res) {
   const cache = getLogStores(CacheKeys.CONFIG_STORE);
 
-  const cachedStartupConfig = await cache.get(CacheKeys.STARTUP_CONFIG);
+  const cacheKey = scopedCacheKey(CacheKeys.STARTUP_CONFIG);
+  const cachedStartupConfig = await cache.get(cacheKey);
   if (cachedStartupConfig) {
     res.send(cachedStartupConfig);
     return;
@@ -37,7 +38,10 @@ router.get('/', async function (req, res) {
   const ldap = getLdapConfig();
 
   try {
-    const appConfig = await getAppConfig({ role: req.user?.role, tenantId: req.user?.tenantId });
+    const appConfig = await getAppConfig({
+      role: req.user?.role,
+      tenantId: req.user?.tenantId || getTenantId(),
+    });
 
     const isOpenIdEnabled =
       !!process.env.OPENID_CLIENT_ID &&
@@ -141,7 +145,7 @@ router.get('/', async function (req, res) {
       payload.customFooter = process.env.CUSTOM_FOOTER;
     }
 
-    await cache.set(CacheKeys.STARTUP_CONFIG, payload);
+    await cache.set(cacheKey, payload);
     return res.status(200).send(payload);
   } catch (err) {
     logger.error('Error in startup config', err);
diff --git a/api/server/services/Config/app.js b/api/server/services/Config/app.js
index 7530ca1031..3256732ec2 100644
--- a/api/server/services/Config/app.js
+++ b/api/server/services/Config/app.js
@@ -1,5 +1,5 @@
 const { CacheKeys } = require('librechat-data-provider');
-const { AppService, logger } = require('@librechat/data-schemas');
+const { AppService, logger, scopedCacheKey } = require('@librechat/data-schemas');
 const { createAppConfigService, clearMcpConfigCache } = require('@librechat/api');
 const { setCachedTools, invalidateCachedTools } = require('./getCachedTools');
 const { loadAndFormatTools } = require('~/server/services/start/tools');
@@ -29,11 +29,23 @@ const { getAppConfig, clearAppConfigCache, clearOverrideCache } = createAppConfi
   getUserPrincipals: db.getUserPrincipals,
 });
 
-/** Deletes the ENDPOINT_CONFIG entry from CONFIG_STORE. Failures are non-critical and swallowed. */
+/**
+ * Deletes ENDPOINT_CONFIG entries from CONFIG_STORE.
+ * Clears both the tenant-scoped key (if in tenant context) and the
+ * unscoped base key (populated by unauthenticated /api/endpoints calls).
+ * Other tenants' scoped keys are NOT actively cleared — they expire
+ * via TTL. Config mutations in one tenant do not propagate immediately
+ * to other tenants' endpoint config caches.
+ */
 async function clearEndpointConfigCache() {
   try {
     const configStore = getLogStores(CacheKeys.CONFIG_STORE);
-    await configStore.delete(CacheKeys.ENDPOINT_CONFIG);
+    const scoped = scopedCacheKey(CacheKeys.ENDPOINT_CONFIG);
+    const keys = [scoped];
+    if (scoped !== CacheKeys.ENDPOINT_CONFIG) {
+      keys.push(CacheKeys.ENDPOINT_CONFIG);
+    }
+    await Promise.all(keys.map((k) => configStore.delete(k)));
   } catch {
     // CONFIG_STORE or ENDPOINT_CONFIG may not exist — not critical
   }
diff --git a/api/server/services/Config/getEndpointsConfig.js b/api/server/services/Config/getEndpointsConfig.js
index 476d3d7c80..cd0230ad4a 100644
--- a/api/server/services/Config/getEndpointsConfig.js
+++ b/api/server/services/Config/getEndpointsConfig.js
@@ -1,3 +1,4 @@
+const { scopedCacheKey } = require('@librechat/data-schemas');
 const { loadCustomEndpointsConfig } = require('@librechat/api');
 const {
   CacheKeys,
@@ -17,10 +18,11 @@ const { getAppConfig } = require('./app');
  */
 async function getEndpointsConfig(req) {
   const cache = getLogStores(CacheKeys.CONFIG_STORE);
-  const cachedEndpointsConfig = await cache.get(CacheKeys.ENDPOINT_CONFIG);
+  const cacheKey = scopedCacheKey(CacheKeys.ENDPOINT_CONFIG);
+  const cachedEndpointsConfig = await cache.get(cacheKey);
   if (cachedEndpointsConfig) {
     if (cachedEndpointsConfig.gptPlugins) {
-      await cache.delete(CacheKeys.ENDPOINT_CONFIG);
+      await cache.delete(cacheKey);
     } else {
       return cachedEndpointsConfig;
     }
@@ -112,7 +114,7 @@ async function getEndpointsConfig(req) {
 
   const endpointsConfig = orderEndpointsConfig(mergedConfig);
 
-  await cache.set(CacheKeys.ENDPOINT_CONFIG, endpointsConfig);
+  await cache.set(cacheKey, endpointsConfig);
   return endpointsConfig;
 }
 
diff --git a/api/server/services/Config/mcp.js b/api/server/services/Config/mcp.js
index cc4e98b59e..869c9e66da 100644
--- a/api/server/services/Config/mcp.js
+++ b/api/server/services/Config/mcp.js
@@ -1,5 +1,5 @@
-const { logger } = require('@librechat/data-schemas');
 const { CacheKeys, Constants } = require('librechat-data-provider');
+const { logger, scopedCacheKey } = require('@librechat/data-schemas');
 const { getCachedTools, setCachedTools } = require('./getCachedTools');
 const { getLogStores } = require('~/cache');
 
@@ -36,7 +36,7 @@ async function updateMCPServerTools({ userId, serverName, tools }) {
     await setCachedTools(serverTools, { userId, serverName });
 
     const cache = getLogStores(CacheKeys.TOOL_CACHE);
-    await cache.delete(CacheKeys.TOOLS);
+    await cache.delete(scopedCacheKey(CacheKeys.TOOLS));
     logger.debug(
       `[MCP Cache] Updated ${tools.length} tools for server ${serverName} (user: ${userId})`,
     );
@@ -48,7 +48,10 @@ async function updateMCPServerTools({ userId, serverName, tools }) {
 }
 
 /**
- * Merges app-level tools with global tools
+ * Merges app-level tools with global tools.
+ * Only the current ALS-scoped key (base key in system/startup context) is cleared.
+ * Tenant-scoped TOOLS:tenantId keys are NOT actively invalidated — they expire
+ * via TTL on the next tenant request. This matches clearEndpointConfigCache behavior.
  * @param {import('@librechat/api').LCAvailableTools} appTools
  * @returns {Promise<void>}
  */
@@ -62,7 +65,7 @@ async function mergeAppTools(appTools) {
     const mergedTools = { ...cachedTools, ...appTools };
     await setCachedTools(mergedTools);
     const cache = getLogStores(CacheKeys.TOOL_CACHE);
-    await cache.delete(CacheKeys.TOOLS);
+    await cache.delete(scopedCacheKey(CacheKeys.TOOLS));
     logger.debug(`Merged ${count} app-level tools`);
   } catch (error) {
     logger.error('Failed to merge app-level tools:', error);
diff --git a/api/server/services/Files/Audio/streamAudio.js b/api/server/services/Files/Audio/streamAudio.js
index c28a96edff..7120399b5e 100644
--- a/api/server/services/Files/Audio/streamAudio.js
+++ b/api/server/services/Files/Audio/streamAudio.js
@@ -1,3 +1,4 @@
+const { scopedCacheKey } = require('@librechat/data-schemas');
 const {
   Time,
   CacheKeys,
@@ -67,6 +68,8 @@ function createChunkProcessor(user, messageId) {
   }
 
   const messageCache = getLogStores(CacheKeys.MESSAGES);
+  // Captured at creation time — must be called within an active request ALS scope
+  const cacheKey = scopedCacheKey(messageId);
 
   /**
    * @returns {Promise<{ text: string, isFinished: boolean }[] | string>}
@@ -81,7 +84,7 @@ function createChunkProcessor(user, messageId) {
     }
 
     /** @type { string | { text: string; complete: boolean } } */
-    let message = await messageCache.get(messageId);
+    let message = await messageCache.get(cacheKey);
     if (!message) {
       message = await getMessage({ user, messageId });
     }
@@ -92,7 +95,7 @@ function createChunkProcessor(user, messageId) {
     } else {
       const text = message.content?.length > 0 ? parseTextParts(message.content) : message.text;
       messageCache.set(
-        messageId,
+        cacheKey,
         {
           text,
           complete: true,
diff --git a/api/server/utils/import/importers.js b/api/server/utils/import/importers.js
index 39734c181c..f8b3be4dab 100644
--- a/api/server/utils/import/importers.js
+++ b/api/server/utils/import/importers.js
@@ -1,5 +1,5 @@
 const { v4: uuidv4 } = require('uuid');
-const { logger } = require('@librechat/data-schemas');
+const { logger, scopedCacheKey } = require('@librechat/data-schemas');
 const { EModelEndpoint, Constants, openAISettings, CacheKeys } = require('librechat-data-provider');
 const { createImportBatchBuilder } = require('./importBatchBuilder');
 const { cloneMessagesWithTimestamps } = require('./fork');
@@ -203,7 +203,7 @@ async function importLibreChatConvo(
     /* Endpoint configuration */
     let endpoint = jsonData.endpoint ?? options.endpoint ?? EModelEndpoint.openAI;
     const cache = getLogStores(CacheKeys.CONFIG_STORE);
-    const endpointsConfig = await cache.get(CacheKeys.ENDPOINT_CONFIG);
+    const endpointsConfig = await cache.get(scopedCacheKey(CacheKeys.ENDPOINT_CONFIG));
     const endpointConfig = endpointsConfig?.[endpoint];
     if (!endpointConfig && endpointsConfig) {
       endpoint = Object.keys(endpointsConfig)[0];
diff --git a/packages/api/src/app/permissions.ts b/packages/api/src/app/permissions.ts
index 5a557adfcf..92da1342ce 100644
--- a/packages/api/src/app/permissions.ts
+++ b/packages/api/src/app/permissions.ts
@@ -1,4 +1,4 @@
-import { logger } from '@librechat/data-schemas';
+import { logger, tenantStorage, SYSTEM_TENANT_ID } from '@librechat/data-schemas';
 import {
   SystemRoles,
   Permissions,
@@ -54,6 +54,7 @@ export async function updateInterfacePermissions({
   appConfig,
   getRoleByName,
   updateAccessPermissions,
+  tenantId,
 }: {
   appConfig: AppConfig;
   getRoleByName: (roleName: string, fieldsToSelect?: string | string[]) => Promise<IRole | null>;
@@ -63,7 +64,19 @@ export async function updateInterfacePermissions({
 
     roleData?: IRole | null,
   ) => Promise<void>;
-}) {
+  /**
+   * Optional tenant ID for scoping role updates to a specific tenant.
+   * When provided (and not SYSTEM_TENANT_ID), runs inside `tenantStorage.run({ tenantId })`.
+   * When omitted or SYSTEM_TENANT_ID, uses the caller's existing ALS context.
+   */
+  tenantId?: string;
+}): Promise<void> {
+  if (tenantId && tenantId !== SYSTEM_TENANT_ID) {
+    return tenantStorage.run({ tenantId }, async () =>
+      updateInterfacePermissions({ appConfig, getRoleByName, updateAccessPermissions }),
+    );
+  }
+
   const loadedInterface = appConfig?.interfaceConfig;
   if (!loadedInterface) {
     return;
diff --git a/packages/api/src/flow/manager.tenant.spec.ts b/packages/api/src/flow/manager.tenant.spec.ts
new file mode 100644
index 0000000000..14b780c34b
--- /dev/null
+++ b/packages/api/src/flow/manager.tenant.spec.ts
@@ -0,0 +1,49 @@
+import { Keyv } from 'keyv';
+import { logger, tenantStorage } from '@librechat/data-schemas';
+import { FlowStateManager } from './manager';
+
+jest.mock('@librechat/data-schemas', () => ({
+  ...jest.requireActual('@librechat/data-schemas'),
+  logger: {
+    info: jest.fn(),
+    warn: jest.fn(),
+    error: jest.fn(),
+    debug: jest.fn(),
+  },
+}));
+
+describe('FlowStateManager flow keys are not tenant-scoped', () => {
+  let manager: FlowStateManager;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    const store = new Keyv({ store: new Map() });
+    manager = new FlowStateManager(store, { ci: true, ttl: 60_000 });
+  });
+
+  it('completeFlow finds a flow regardless of tenant context (OAuth callback compatibility)', async () => {
+    await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+      await manager.initFlow('flow-1', 'oauth', {});
+    });
+
+    const found = await manager.completeFlow('flow-1', 'oauth', { token: 'abc' });
+    expect(found).toBe(true);
+  });
+
+  it('completeFlow works when both creation and completion have the same tenant', async () => {
+    await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+      await manager.initFlow('flow-2', 'oauth', {});
+      const found = await manager.completeFlow('flow-2', 'oauth', { token: 'abc' });
+      expect(found).toBe(true);
+    });
+  });
+
+  it('completeFlow returns false and logs when flow does not exist', async () => {
+    const found = await manager.completeFlow('ghost-flow', 'oauth', { token: 'x' });
+    expect(found).toBe(false);
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('ghost-flow'),
+      expect.objectContaining({ flowId: 'ghost-flow', type: 'oauth' }),
+    );
+  });
+});
diff --git a/packages/api/src/flow/manager.ts b/packages/api/src/flow/manager.ts
index b68b9edb7a..544cba9560 100644
--- a/packages/api/src/flow/manager.ts
+++ b/packages/api/src/flow/manager.ts
@@ -53,6 +53,12 @@ export class FlowStateManager<T = unknown> {
     process.on('SIGHUP', cleanup);
   }
 
+  /**
+   * Flow keys are intentionally NOT tenant-scoped. OAuth callbacks arrive
+   * without tenant ALS context (the provider redirect doesn't carry
+   * X-Tenant-Id). Flow IDs are random UUIDs with no collision risk, and
+   * flow data is ephemeral (TTL-bounded, no sensitive user content).
+   */
   private getFlowKey(flowId: string, type: string): string {
     return `${type}:${flowId}`;
   }
@@ -253,7 +259,9 @@ export class FlowStateManager<T = unknown> {
 
     if (!flowState) {
       logger.warn(
-        '[FlowStateManager] Flow state not found during completion — cannot recover metadata, skipping',
+        `[FlowStateManager] completeFlow: flow not found — key=${flowKey}. ` +
+          'Possible causes: flow TTL expired before callback arrived, flow was never created, or ' +
+          'the callback is routing to a different instance without shared Keyv storage.',
         { flowId, type },
       );
       return false;
diff --git a/packages/api/src/mcp/__tests__/MCPOAuthCSRFFallback.test.ts b/packages/api/src/mcp/__tests__/MCPOAuthCSRFFallback.test.ts
index cdba06cf8d..c0a861817c 100644
--- a/packages/api/src/mcp/__tests__/MCPOAuthCSRFFallback.test.ts
+++ b/packages/api/src/mcp/__tests__/MCPOAuthCSRFFallback.test.ts
@@ -34,6 +34,8 @@ jest.mock('@librechat/data-schemas', () => ({
     error: jest.fn(),
     debug: jest.fn(),
   },
+  getTenantId: jest.fn(),
+  SYSTEM_TENANT_ID: '__SYSTEM__',
   encryptV2: jest.fn(async (val: string) => `enc:${val}`),
   decryptV2: jest.fn(async (val: string) => val.replace(/^enc:/, '')),
 }));
diff --git a/packages/api/src/mcp/__tests__/MCPOAuthFlow.test.ts b/packages/api/src/mcp/__tests__/MCPOAuthFlow.test.ts
index f73a5ed3e8..7e26165cad 100644
--- a/packages/api/src/mcp/__tests__/MCPOAuthFlow.test.ts
+++ b/packages/api/src/mcp/__tests__/MCPOAuthFlow.test.ts
@@ -20,6 +20,8 @@ jest.mock('@librechat/data-schemas', () => ({
     error: jest.fn(),
     debug: jest.fn(),
   },
+  getTenantId: jest.fn(),
+  SYSTEM_TENANT_ID: '__SYSTEM__',
   encryptV2: jest.fn(async (val: string) => `enc:${val}`),
   decryptV2: jest.fn(async (val: string) => val.replace(/^enc:/, '')),
 }));
diff --git a/packages/api/src/mcp/__tests__/MCPOAuthRaceCondition.test.ts b/packages/api/src/mcp/__tests__/MCPOAuthRaceCondition.test.ts
index cb6187ab45..d5fb1d67f7 100644
--- a/packages/api/src/mcp/__tests__/MCPOAuthRaceCondition.test.ts
+++ b/packages/api/src/mcp/__tests__/MCPOAuthRaceCondition.test.ts
@@ -23,6 +23,8 @@ jest.mock('@librechat/data-schemas', () => ({
     error: jest.fn(),
     debug: jest.fn(),
   },
+  getTenantId: jest.fn(),
+  SYSTEM_TENANT_ID: '__SYSTEM__',
   encryptV2: jest.fn(async (val: string) => `enc:${val}`),
   decryptV2: jest.fn(async (val: string) => val.replace(/^enc:/, '')),
 }));
@@ -258,7 +260,7 @@ describe('MCP OAuth Race Condition Fixes', () => {
       expect(stateAfterComplete).toBeUndefined();
 
       expect(mockLogger.warn).toHaveBeenCalledWith(
-        expect.stringContaining('cannot recover metadata'),
+        expect.stringContaining('flow not found'),
         expect.any(Object),
       );
     });
diff --git a/packages/api/src/mcp/__tests__/MCPOAuthTokenExpiry.test.ts b/packages/api/src/mcp/__tests__/MCPOAuthTokenExpiry.test.ts
index 986ac4c8b4..b5cbc869a8 100644
--- a/packages/api/src/mcp/__tests__/MCPOAuthTokenExpiry.test.ts
+++ b/packages/api/src/mcp/__tests__/MCPOAuthTokenExpiry.test.ts
@@ -26,6 +26,8 @@ jest.mock('@librechat/data-schemas', () => ({
     error: jest.fn(),
     debug: jest.fn(),
   },
+  getTenantId: jest.fn(),
+  SYSTEM_TENANT_ID: '__SYSTEM__',
   encryptV2: jest.fn(async (val: string) => `enc:${val}`),
   decryptV2: jest.fn(async (val: string) => val.replace(/^enc:/, '')),
 }));
diff --git a/packages/api/src/middleware/index.ts b/packages/api/src/middleware/index.ts
index 7d9dee2f8a..b91fee2999 100644
--- a/packages/api/src/middleware/index.ts
+++ b/packages/api/src/middleware/index.ts
@@ -6,5 +6,6 @@ export * from './balance';
 export * from './json';
 export * from './capabilities';
 export { tenantContextMiddleware } from './tenant';
+export { preAuthTenantMiddleware } from './preAuthTenant';
 export * from './concurrency';
 export * from './checkBalance';
diff --git a/packages/api/src/middleware/preAuthTenant.spec.ts b/packages/api/src/middleware/preAuthTenant.spec.ts
new file mode 100644
index 0000000000..ed35da2324
--- /dev/null
+++ b/packages/api/src/middleware/preAuthTenant.spec.ts
@@ -0,0 +1,129 @@
+import { getTenantId, logger } from '@librechat/data-schemas';
+import { preAuthTenantMiddleware } from './preAuthTenant';
+import type { Request, Response, NextFunction } from 'express';
+
+jest.mock('@librechat/data-schemas', () => ({
+  ...jest.requireActual('@librechat/data-schemas'),
+  logger: {
+    warn: jest.fn(),
+    error: jest.fn(),
+    info: jest.fn(),
+    debug: jest.fn(),
+  },
+}));
+
+describe('preAuthTenantMiddleware', () => {
+  let req: Partial<Request>;
+  let res: Partial<Response>;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    req = { headers: {} };
+    res = {};
+  });
+
+  it('calls next() without ALS context when no X-Tenant-Id header is present', () => {
+    let capturedTenantId: string | undefined = 'sentinel';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+  });
+
+  it('calls next() without ALS context when X-Tenant-Id header is empty', () => {
+    req.headers = { 'x-tenant-id': '' };
+    let capturedTenantId: string | undefined = 'sentinel';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+  });
+
+  it('wraps downstream in ALS context when X-Tenant-Id header is present', () => {
+    req.headers = { 'x-tenant-id': 'acme-corp' };
+    let capturedTenantId: string | undefined;
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBe('acme-corp');
+  });
+
+  it('ignores __SYSTEM__ sentinel and logs warning', () => {
+    req.headers = { 'x-tenant-id': '__SYSTEM__' };
+    req.ip = '10.0.0.1';
+    req.path = '/api/config';
+    let capturedTenantId: string | undefined = 'should-be-overwritten';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('__SYSTEM__'),
+      expect.objectContaining({ ip: '10.0.0.1', path: '/api/config' }),
+    );
+  });
+
+  it('ignores array-valued headers (Express can produce these)', () => {
+    req.headers = { 'x-tenant-id': ['a', 'b'] as unknown as string };
+    let capturedTenantId: string | undefined = 'sentinel';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+  });
+
+  it('ignores tenant IDs containing invalid characters and logs warning', () => {
+    req.headers = { 'x-tenant-id': 'tenant:injected' };
+    req.ip = '192.168.1.1';
+    req.path = '/api/auth/login';
+    let capturedTenantId: string | undefined = 'sentinel';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('malformed'),
+      expect.objectContaining({ ip: '192.168.1.1', path: '/api/auth/login' }),
+    );
+  });
+
+  it('trims whitespace from tenant ID header', () => {
+    req.headers = { 'x-tenant-id': '  acme-corp  ' };
+    let capturedTenantId: string | undefined;
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBe('acme-corp');
+  });
+
+  it('ignores tenant IDs exceeding max length and logs warning', () => {
+    req.headers = { 'x-tenant-id': 'a'.repeat(200) };
+    req.ip = '192.168.1.1';
+    req.path = '/api/share/abc';
+    let capturedTenantId: string | undefined = 'sentinel';
+    const capturedNext: NextFunction = () => {
+      capturedTenantId = getTenantId();
+    };
+
+    preAuthTenantMiddleware(req as Request, res as Response, capturedNext);
+    expect(capturedTenantId).toBeUndefined();
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.stringContaining('malformed'),
+      expect.objectContaining({ ip: '192.168.1.1', length: 200, path: '/api/share/abc' }),
+    );
+  });
+});
diff --git a/packages/api/src/middleware/preAuthTenant.ts b/packages/api/src/middleware/preAuthTenant.ts
new file mode 100644
index 0000000000..bab91f3a18
--- /dev/null
+++ b/packages/api/src/middleware/preAuthTenant.ts
@@ -0,0 +1,72 @@
+import { tenantStorage, logger, SYSTEM_TENANT_ID } from '@librechat/data-schemas';
+import type { Request, Response, NextFunction } from 'express';
+
+/**
+ * Pre-authentication tenant context middleware for unauthenticated routes.
+ *
+ * Reads the tenant identifier from the `X-Tenant-Id` request header and wraps
+ * downstream handlers in `tenantStorage.run()` so that Mongoose queries and
+ * config resolution run within the correct tenant scope.
+ *
+ * **Where to use**: Mount on routes that must be tenant-aware before
+ * authentication has occurred:
+ * - `GET /api/config` — login page needs tenant-specific config (social logins, registration)
+ * - `/api/auth/*` — login, register, password reset
+ * - `/oauth/*` — OAuth callback flows
+ * - `GET /api/share/:shareId` — public shared conversation links
+ *
+ * **How the header gets set**: The deployment's reverse proxy, auth gateway,
+ * or OpenID strategy sets `X-Tenant-Id` based on subdomain, path, or OIDC claim.
+ * This middleware does NOT resolve tenants from subdomains or tokens — that is
+ * the responsibility of the deployment layer.
+ *
+ * **Design**: Intentionally minimal. No subdomain parsing, no OIDC claim
+ * extraction, no YAML-driven strategy. Multi-tenant deployments can:
+ * 1. Set the header in the reverse proxy / ingress (simplest),
+ * 2. Replace this middleware's resolver logic entirely, or
+ * 3. Layer additional resolution on top (e.g., OpenID `tenant` claim → header).
+ *
+ * If no header is present, downstream runs without tenant ALS context (same as
+ * single-tenant mode). This preserves backward compatibility.
+ */
+const MAX_TENANT_ID_LENGTH = 128;
+const VALID_TENANT_ID = /^[-a-zA-Z0-9_.]+$/;
+
+export function preAuthTenantMiddleware(req: Request, res: Response, next: NextFunction): void {
+  const raw = req.headers['x-tenant-id'];
+
+  if (!raw || typeof raw !== 'string') {
+    next();
+    return;
+  }
+
+  const tenantId = raw.trim();
+
+  if (!tenantId) {
+    next();
+    return;
+  }
+
+  if (tenantId === SYSTEM_TENANT_ID) {
+    logger.warn('[preAuthTenant] Rejected __SYSTEM__ sentinel in X-Tenant-Id header', {
+      ip: req.ip,
+      path: req.path,
+    });
+    next();
+    return;
+  }
+
+  if (tenantId.length > MAX_TENANT_ID_LENGTH || !VALID_TENANT_ID.test(tenantId)) {
+    logger.warn('[preAuthTenant] Rejected malformed X-Tenant-Id header', {
+      ip: req.ip,
+      length: tenantId.length,
+      path: req.path,
+    });
+    next();
+    return;
+  }
+
+  return void tenantStorage.run({ tenantId }, async () => {
+    next();
+  });
+}
diff --git a/packages/api/src/stream/GenerationJobManager.ts b/packages/api/src/stream/GenerationJobManager.ts
index 3e04ab734b..5993c911ff 100644
--- a/packages/api/src/stream/GenerationJobManager.ts
+++ b/packages/api/src/stream/GenerationJobManager.ts
@@ -1,4 +1,4 @@
-import { logger } from '@librechat/data-schemas';
+import { logger, getTenantId, SYSTEM_TENANT_ID } from '@librechat/data-schemas';
 import type { StandardGraph } from '@librechat/agents';
 import { parseTextParts } from 'librechat-data-provider';
 import type { Agents, TMessageContentParts } from 'librechat-data-provider';
@@ -197,7 +197,9 @@ class GenerationJobManagerClass {
     userId: string,
     conversationId?: string,
   ): Promise<t.GenerationJob> {
-    const jobData = await this.jobStore.createJob(streamId, userId, conversationId);
+    const tenantId = getTenantId();
+    const safeTenantId = tenantId && tenantId !== SYSTEM_TENANT_ID ? tenantId : undefined;
+    const jobData = await this.jobStore.createJob(streamId, userId, conversationId, safeTenantId);
 
     /**
      * Create runtime state with readyPromise.
@@ -355,6 +357,7 @@ class GenerationJobManagerClass {
       error: jobData.error,
       metadata: {
         userId: jobData.userId,
+        tenantId: jobData.tenantId,
         conversationId: jobData.conversationId,
         userMessage: jobData.userMessage,
         responseMessageId: jobData.responseMessageId,
@@ -1255,8 +1258,8 @@ class GenerationJobManagerClass {
    * @param userId - The user ID to query
    * @returns Array of conversation IDs with active jobs
    */
-  async getActiveJobIdsForUser(userId: string): Promise<string[]> {
-    return this.jobStore.getActiveJobIdsByUser(userId);
+  async getActiveJobIdsForUser(userId: string, tenantId?: string): Promise<string[]> {
+    return this.jobStore.getActiveJobIdsByUser(userId, tenantId);
   }
 
   /**
diff --git a/packages/api/src/stream/implementations/InMemoryJobStore.ts b/packages/api/src/stream/implementations/InMemoryJobStore.ts
index cc82a69963..7280c3ce80 100644
--- a/packages/api/src/stream/implementations/InMemoryJobStore.ts
+++ b/packages/api/src/stream/implementations/InMemoryJobStore.ts
@@ -70,6 +70,7 @@ export class InMemoryJobStore implements IJobStore {
     streamId: string,
     userId: string,
     conversationId?: string,
+    tenantId?: string,
   ): Promise<SerializableJobData> {
     if (this.jobs.size >= this.maxJobs) {
       await this.evictOldest();
@@ -78,6 +79,7 @@ export class InMemoryJobStore implements IJobStore {
     const job: SerializableJobData = {
       streamId,
       userId,
+      ...(tenantId && { tenantId }),
       status: 'running',
       createdAt: Date.now(),
       conversationId,
@@ -86,11 +88,12 @@ export class InMemoryJobStore implements IJobStore {
 
     this.jobs.set(streamId, job);
 
-    // Track job by userId for efficient user-scoped queries
-    let userJobs = this.userJobMap.get(userId);
+    // Track job by userId (tenant-qualified when available) for efficient user-scoped queries
+    const userKey = tenantId ? `${tenantId}:${userId}` : userId;
+    let userJobs = this.userJobMap.get(userKey);
     if (!userJobs) {
       userJobs = new Set();
-      this.userJobMap.set(userId, userJobs);
+      this.userJobMap.set(userKey, userJobs);
     }
     userJobs.add(streamId);
 
@@ -146,6 +149,17 @@ export class InMemoryJobStore implements IJobStore {
     }
 
     for (const id of toDelete) {
+      const job = this.jobs.get(id);
+      if (job) {
+        const userKey = job.tenantId ? `${job.tenantId}:${job.userId}` : job.userId;
+        const userJobs = this.userJobMap.get(userKey);
+        if (userJobs) {
+          userJobs.delete(id);
+          if (userJobs.size === 0) {
+            this.userJobMap.delete(userKey);
+          }
+        }
+      }
       await this.deleteJob(id);
     }
 
@@ -169,6 +183,17 @@ export class InMemoryJobStore implements IJobStore {
 
     if (oldestId) {
       logger.warn(`[InMemoryJobStore] Evicting oldest job: ${oldestId}`);
+      const job = this.jobs.get(oldestId);
+      if (job) {
+        const userKey = job.tenantId ? `${job.tenantId}:${job.userId}` : job.userId;
+        const userJobs = this.userJobMap.get(userKey);
+        if (userJobs) {
+          userJobs.delete(oldestId);
+          if (userJobs.size === 0) {
+            this.userJobMap.delete(userKey);
+          }
+        }
+      }
       await this.deleteJob(oldestId);
     }
   }
@@ -205,8 +230,9 @@ export class InMemoryJobStore implements IJobStore {
    * Returns conversation IDs of running jobs belonging to the user.
    * Also performs self-healing cleanup: removes stale entries for jobs that no longer exist.
    */
-  async getActiveJobIdsByUser(userId: string): Promise<string[]> {
-    const trackedIds = this.userJobMap.get(userId);
+  async getActiveJobIdsByUser(userId: string, tenantId?: string): Promise<string[]> {
+    const userKey = tenantId ? `${tenantId}:${userId}` : userId;
+    const trackedIds = this.userJobMap.get(userKey);
     if (!trackedIds || trackedIds.size === 0) {
       return [];
     }
@@ -226,7 +252,7 @@ export class InMemoryJobStore implements IJobStore {
 
     // Clean up empty set
     if (trackedIds.size === 0) {
-      this.userJobMap.delete(userId);
+      this.userJobMap.delete(userKey);
     }
 
     return activeIds;
diff --git a/packages/api/src/stream/implementations/RedisJobStore.ts b/packages/api/src/stream/implementations/RedisJobStore.ts
index 727fe066eb..a631bc2044 100644
--- a/packages/api/src/stream/implementations/RedisJobStore.ts
+++ b/packages/api/src/stream/implementations/RedisJobStore.ts
@@ -29,8 +29,9 @@ const KEYS = {
   runSteps: (streamId: string) => `stream:{${streamId}}:runsteps`,
   /** Running jobs set for cleanup (global set - single slot) */
   runningJobs: 'stream:running',
-  /** User's active jobs set: stream:user:{userId}:jobs */
-  userJobs: (userId: string) => `stream:user:{${userId}}:jobs`,
+  /** User's active jobs set, tenant-qualified when tenantId is available */
+  userJobs: (userId: string, tenantId?: string) =>
+    tenantId ? `stream:user:{${tenantId}:${userId}}:jobs` : `stream:user:{${userId}}:jobs`,
 };
 
 /**
@@ -140,10 +141,12 @@ export class RedisJobStore implements IJobStore {
     streamId: string,
     userId: string,
     conversationId?: string,
+    tenantId?: string,
   ): Promise<SerializableJobData> {
     const job: SerializableJobData = {
       streamId,
       userId,
+      ...(tenantId && { tenantId }),
       status: 'running',
       createdAt: Date.now(),
       conversationId,
@@ -151,7 +154,7 @@ export class RedisJobStore implements IJobStore {
     };
 
     const key = KEYS.job(streamId);
-    const userJobsKey = KEYS.userJobs(userId);
+    const userJobsKey = KEYS.userJobs(userId, tenantId);
 
     // For cluster mode, we can't pipeline keys on different slots
     // The job key uses hash tag {streamId}, runningJobs and userJobs are on different slots
@@ -377,8 +380,8 @@ export class RedisJobStore implements IJobStore {
    * @param userId - The user ID to query
    * @returns Array of conversation IDs with active jobs
    */
-  async getActiveJobIdsByUser(userId: string): Promise<string[]> {
-    const userJobsKey = KEYS.userJobs(userId);
+  async getActiveJobIdsByUser(userId: string, tenantId?: string): Promise<string[]> {
+    const userJobsKey = KEYS.userJobs(userId, tenantId);
     const trackedIds = await this.redis.smembers(userJobsKey);
 
     if (trackedIds.length === 0) {
@@ -868,6 +871,7 @@ export class RedisJobStore implements IJobStore {
     return {
       streamId: data.streamId,
       userId: data.userId,
+      tenantId: data.tenantId || undefined,
       status: data.status as JobStatus,
       createdAt: parseInt(data.createdAt, 10),
       completedAt: data.completedAt ? parseInt(data.completedAt, 10) : undefined,
diff --git a/packages/api/src/stream/interfaces/IJobStore.ts b/packages/api/src/stream/interfaces/IJobStore.ts
index fadddb840d..b59eed66f8 100644
--- a/packages/api/src/stream/interfaces/IJobStore.ts
+++ b/packages/api/src/stream/interfaces/IJobStore.ts
@@ -12,6 +12,7 @@ export type JobStatus = 'running' | 'complete' | 'error' | 'aborted';
 export interface SerializableJobData {
   streamId: string;
   userId: string;
+  tenantId?: string;
   status: JobStatus;
   createdAt: number;
   completedAt?: number;
@@ -149,6 +150,7 @@ export interface IJobStore {
     streamId: string,
     userId: string,
     conversationId?: string,
+    tenantId?: string,
   ): Promise<SerializableJobData>;
 
   /** Get a job by streamId (streamId === conversationId) */
@@ -186,7 +188,7 @@ export interface IJobStore {
    * @param userId - The user ID to query
    * @returns Array of conversation IDs with active jobs
    */
-  getActiveJobIdsByUser(userId: string): Promise<string[]>;
+  getActiveJobIdsByUser(userId: string, tenantId?: string): Promise<string[]>;
 
   // ===== Content State Methods =====
   // These methods manage volatile content state tied to each job.
diff --git a/packages/api/src/types/stream.ts b/packages/api/src/types/stream.ts
index 068d9c8db8..dd125a1aab 100644
--- a/packages/api/src/types/stream.ts
+++ b/packages/api/src/types/stream.ts
@@ -4,6 +4,7 @@ import type { ServerSentEvent } from '~/types';
 
 export interface GenerationJobMetadata {
   userId: string;
+  tenantId?: string;
   conversationId?: string;
   /** User message data for rebuilding submission on reconnect */
   userMessage?: Agents.UserMessageMeta;
diff --git a/packages/data-schemas/src/config/tenantContext.spec.ts b/packages/data-schemas/src/config/tenantContext.spec.ts
new file mode 100644
index 0000000000..7e6cc0748d
--- /dev/null
+++ b/packages/data-schemas/src/config/tenantContext.spec.ts
@@ -0,0 +1,26 @@
+import { tenantStorage, runAsSystem, scopedCacheKey } from './tenantContext';
+
+describe('scopedCacheKey', () => {
+  it('returns base key when no ALS context is set', () => {
+    expect(scopedCacheKey('MODELS_CONFIG')).toBe('MODELS_CONFIG');
+  });
+
+  it('returns base key in SYSTEM_TENANT_ID context', async () => {
+    await runAsSystem(async () => {
+      expect(scopedCacheKey('MODELS_CONFIG')).toBe('MODELS_CONFIG');
+    });
+  });
+
+  it('appends tenantId when tenant context is active', async () => {
+    await tenantStorage.run({ tenantId: 'acme' }, async () => {
+      expect(scopedCacheKey('MODELS_CONFIG')).toBe('MODELS_CONFIG:acme');
+    });
+  });
+
+  it('does not leak tenant context outside ALS scope', async () => {
+    await tenantStorage.run({ tenantId: 'acme' }, async () => {
+      expect(scopedCacheKey('KEY')).toBe('KEY:acme');
+    });
+    expect(scopedCacheKey('KEY')).toBe('KEY');
+  });
+});
diff --git a/packages/data-schemas/src/config/tenantContext.ts b/packages/data-schemas/src/config/tenantContext.ts
index e5e4376a90..eb77edb27d 100644
--- a/packages/data-schemas/src/config/tenantContext.ts
+++ b/packages/data-schemas/src/config/tenantContext.ts
@@ -26,3 +26,16 @@ export function getTenantId(): string | undefined {
 export function runAsSystem<T>(fn: () => Promise<T>): Promise<T> {
   return tenantStorage.run({ tenantId: SYSTEM_TENANT_ID }, fn);
 }
+
+/**
+ * Appends `:${tenantId}` to a cache key when a non-system tenant context is active.
+ * Returns the base key unchanged when no ALS context is set or when running
+ * inside `runAsSystem()` (SYSTEM_TENANT_ID context).
+ */
+export function scopedCacheKey(baseKey: string): string {
+  const tenantId = getTenantId();
+  if (!tenantId || tenantId === SYSTEM_TENANT_ID) {
+    return baseKey;
+  }
+  return `${baseKey}:${tenantId}`;
+}
diff --git a/packages/data-schemas/src/index.ts b/packages/data-schemas/src/index.ts
index d673db1f5c..1139f83f17 100644
--- a/packages/data-schemas/src/index.ts
+++ b/packages/data-schemas/src/index.ts
@@ -19,6 +19,12 @@ export type * from './types';
 export type * from './methods';
 export { default as logger } from './config/winston';
 export { default as meiliLogger } from './config/meiliLogger';
-export { tenantStorage, getTenantId, runAsSystem, SYSTEM_TENANT_ID } from './config/tenantContext';
+export {
+  tenantStorage,
+  getTenantId,
+  runAsSystem,
+  scopedCacheKey,
+  SYSTEM_TENANT_ID,
+} from './config/tenantContext';
 export type { TenantContext } from './config/tenantContext';
 export { dropSupersededTenantIndexes, dropSupersededPromptGroupIndexes } from './migrations';
diff --git a/packages/data-schemas/src/methods/aclEntry.ts b/packages/data-schemas/src/methods/aclEntry.ts
index 82e277254a..2f61861029 100644
--- a/packages/data-schemas/src/methods/aclEntry.ts
+++ b/packages/data-schemas/src/methods/aclEntry.ts
@@ -8,6 +8,7 @@ import type {
   Model,
 } from 'mongoose';
 import type { IAclEntry } from '~/types';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
 
 export function createAclEntryMethods(mongoose: typeof import('mongoose')) {
   /**
@@ -378,7 +379,7 @@ export function createAclEntryMethods(mongoose: typeof import('mongoose')) {
     options?: { session?: ClientSession },
   ) {
     const AclEntry = mongoose.models.AclEntry as Model<IAclEntry>;
-    return AclEntry.bulkWrite(ops, options || {});
+    return tenantSafeBulkWrite(AclEntry, ops, options || {});
   }
 
   /**
@@ -448,7 +449,9 @@ export function createAclEntryMethods(mongoose: typeof import('mongoose')) {
       { $group: { _id: '$resourceId' } },
     ]);
 
-    const multiOwnerIds = new Set(otherOwners.map((doc: { _id: Types.ObjectId }) => doc._id.toString()));
+    const multiOwnerIds = new Set(
+      otherOwners.map((doc: { _id: Types.ObjectId }) => doc._id.toString()),
+    );
     return ownedIds.filter((id) => !multiOwnerIds.has(id.toString()));
   }
 
diff --git a/packages/data-schemas/src/methods/agentCategory.ts b/packages/data-schemas/src/methods/agentCategory.ts
index 2dd4678075..baf33207aa 100644
--- a/packages/data-schemas/src/methods/agentCategory.ts
+++ b/packages/data-schemas/src/methods/agentCategory.ts
@@ -1,5 +1,6 @@
 import type { Model, Types } from 'mongoose';
 import type { IAgentCategory } from '~/types';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
 
 export function createAgentCategoryMethods(mongoose: typeof import('mongoose')) {
   /**
@@ -74,7 +75,7 @@ export function createAgentCategoryMethods(mongoose: typeof import('mongoose'))
       },
     }));
 
-    return await AgentCategory.bulkWrite(operations);
+    return await tenantSafeBulkWrite(AgentCategory, operations);
   }
 
   /**
@@ -241,7 +242,7 @@ export function createAgentCategoryMethods(mongoose: typeof import('mongoose'))
         },
       }));
 
-      await AgentCategory.bulkWrite(bulkOps, { ordered: false });
+      await tenantSafeBulkWrite(AgentCategory, bulkOps, { ordered: false });
     }
 
     return updates.length > 0 || created > 0;
diff --git a/packages/data-schemas/src/methods/conversation.ts b/packages/data-schemas/src/methods/conversation.ts
index 7a62afef9e..abfe16bf2d 100644
--- a/packages/data-schemas/src/methods/conversation.ts
+++ b/packages/data-schemas/src/methods/conversation.ts
@@ -1,6 +1,7 @@
 import type { FilterQuery, Model, SortOrder } from 'mongoose';
-import logger from '~/config/winston';
 import { createTempChatExpirationDate } from '~/utils/tempChatRetention';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
+import logger from '~/config/winston';
 import type { AppConfig, IConversation } from '~/types';
 import type { MessageMethods } from './message';
 import type { DeleteResult } from 'mongoose';
@@ -228,7 +229,7 @@ export function createConversationMethods(
         },
       }));
 
-      const result = await Conversation.bulkWrite(bulkOps);
+      const result = await tenantSafeBulkWrite(Conversation, bulkOps);
       return result;
     } catch (error) {
       logger.error('[bulkSaveConvos] Error saving conversations in bulk', error);
diff --git a/packages/data-schemas/src/methods/conversationTag.ts b/packages/data-schemas/src/methods/conversationTag.ts
index af1e43babb..085948bab5 100644
--- a/packages/data-schemas/src/methods/conversationTag.ts
+++ b/packages/data-schemas/src/methods/conversationTag.ts
@@ -1,4 +1,5 @@
 import type { Model } from 'mongoose';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
 import logger from '~/config/winston';
 
 interface IConversationTag {
@@ -233,7 +234,7 @@ export function createConversationTagMethods(mongoose: typeof import('mongoose')
       }
 
       if (bulkOps.length > 0) {
-        await ConversationTag.bulkWrite(bulkOps);
+        await tenantSafeBulkWrite(ConversationTag, bulkOps);
       }
 
       const updatedConversation = (
@@ -273,7 +274,7 @@ export function createConversationTagMethods(mongoose: typeof import('mongoose')
         },
       }));
 
-      const result = await ConversationTag.bulkWrite(bulkOps);
+      const result = await tenantSafeBulkWrite(ConversationTag, bulkOps);
       if (result && result.modifiedCount > 0) {
         logger.debug(
           `user: ${user} | Incremented tag counts - modified ${result.modifiedCount} tags`,
diff --git a/packages/data-schemas/src/methods/file.ts b/packages/data-schemas/src/methods/file.ts
index 3d7db88c3f..4c0969afb3 100644
--- a/packages/data-schemas/src/methods/file.ts
+++ b/packages/data-schemas/src/methods/file.ts
@@ -2,6 +2,7 @@ import logger from '../config/winston';
 import { EToolResources, FileContext } from 'librechat-data-provider';
 import type { FilterQuery, SortOrder, Model } from 'mongoose';
 import type { IMongoFile } from '~/types/file';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
 
 /** Factory function that takes mongoose instance and returns the file methods */
 export function createFileMethods(mongoose: typeof import('mongoose')) {
@@ -322,7 +323,7 @@ export function createFileMethods(mongoose: typeof import('mongoose')) {
       },
     }));
 
-    const result = await File.bulkWrite(bulkOperations);
+    const result = await tenantSafeBulkWrite(File, bulkOperations);
     logger.info(`Updated ${result.modifiedCount} files with new S3 URLs`);
   }
 
diff --git a/packages/data-schemas/src/methods/message.ts b/packages/data-schemas/src/methods/message.ts
index ae5ca72b12..2e638b6bfb 100644
--- a/packages/data-schemas/src/methods/message.ts
+++ b/packages/data-schemas/src/methods/message.ts
@@ -1,6 +1,7 @@
 import type { DeleteResult, FilterQuery, Model } from 'mongoose';
 import logger from '~/config/winston';
 import { createTempChatExpirationDate } from '~/utils/tempChatRetention';
+import { tenantSafeBulkWrite } from '~/utils/tenantBulkWrite';
 import type { AppConfig, IMessage } from '~/types';
 
 /** Simple UUID v4 regex to replace zod validation */
@@ -165,7 +166,7 @@ export function createMessageMethods(mongoose: typeof import('mongoose')): Messa
           upsert: true,
         },
       }));
-      const result = await Message.bulkWrite(bulkOps);
+      const result = await tenantSafeBulkWrite(Message, bulkOps);
       return result;
     } catch (err) {
       logger.error('Error saving messages in bulk:', err);
diff --git a/packages/data-schemas/src/methods/prompt.ts b/packages/data-schemas/src/methods/prompt.ts
index a1b6bfde37..86d830fecd 100644
--- a/packages/data-schemas/src/methods/prompt.ts
+++ b/packages/data-schemas/src/methods/prompt.ts
@@ -1,8 +1,9 @@
 import { ResourceType, SystemCategories } from 'librechat-data-provider';
 import type { Model, Types } from 'mongoose';
 import type { IAclEntry, IPrompt, IPromptGroup, IPromptGroupDocument } from '~/types';
-import { escapeRegExp } from '~/utils/string';
+import { getTenantId, SYSTEM_TENANT_ID } from '~/config/tenantContext';
 import { isValidObjectIdString } from '~/utils/objectId';
+import { escapeRegExp } from '~/utils/string';
 import logger from '~/config/winston';
 
 export interface PromptDeps {
@@ -508,16 +509,37 @@ export function createPromptMethods(mongoose: typeof import('mongoose'), deps: P
       if (typeof matchFilter._id === 'string') {
         matchFilter._id = new ObjectId(matchFilter._id);
       }
+      const tenantId = getTenantId();
+      const useTenantFilter = tenantId && tenantId !== SYSTEM_TENANT_ID;
+
+      const lookupStage = useTenantFilter
+        ? {
+            $lookup: {
+              from: 'prompts',
+              let: { prodId: '$productionId' },
+              pipeline: [
+                {
+                  $match: {
+                    $expr: { $eq: ['$_id', '$$prodId'] },
+                    tenantId,
+                  },
+                },
+              ],
+              as: 'productionPrompt',
+            },
+          }
+        : {
+            $lookup: {
+              from: 'prompts',
+              localField: 'productionId',
+              foreignField: '_id',
+              as: 'productionPrompt',
+            },
+          };
+
       const result = await PromptGroup.aggregate([
         { $match: matchFilter },
-        {
-          $lookup: {
-            from: 'prompts',
-            localField: 'productionId',
-            foreignField: '_id',
-            as: 'productionPrompt',
-          },
-        },
+        lookupStage,
         { $unwind: { path: '$productionPrompt', preserveNullAndEmptyArrays: true } },
       ]);
       const group = result[0] || null;
diff --git a/packages/data-schemas/src/migrations/tenantIndexes.spec.ts b/packages/data-schemas/src/migrations/tenantIndexes.spec.ts
index 4637e7d0ad..e62b587a6e 100644
--- a/packages/data-schemas/src/migrations/tenantIndexes.spec.ts
+++ b/packages/data-schemas/src/migrations/tenantIndexes.spec.ts
@@ -47,7 +47,13 @@ describe('dropSupersededTenantIndexes', () => {
       await db.createCollection('roles');
       await db.collection('roles').createIndex({ name: 1 }, { unique: true, name: 'name_1' });
 
+      await db.createCollection('agents');
+      await db.collection('agents').createIndex({ id: 1 }, { unique: true, name: 'id_1' });
+
       await db.createCollection('conversations');
+      await db
+        .collection('conversations')
+        .createIndex({ conversationId: 1 }, { unique: true, name: 'conversationId_1' });
       await db
         .collection('conversations')
         .createIndex(
@@ -56,10 +62,18 @@ describe('dropSupersededTenantIndexes', () => {
         );
 
       await db.createCollection('messages');
+      await db
+        .collection('messages')
+        .createIndex({ messageId: 1 }, { unique: true, name: 'messageId_1' });
       await db
         .collection('messages')
         .createIndex({ messageId: 1, user: 1 }, { unique: true, name: 'messageId_1_user_1' });
 
+      await db.createCollection('presets');
+      await db
+        .collection('presets')
+        .createIndex({ presetId: 1 }, { unique: true, name: 'presetId_1' });
+
       await db.createCollection('agentcategories');
       await db
         .collection('agentcategories')
diff --git a/packages/data-schemas/src/migrations/tenantIndexes.ts b/packages/data-schemas/src/migrations/tenantIndexes.ts
index c68df4db2b..a8b4e51768 100644
--- a/packages/data-schemas/src/migrations/tenantIndexes.ts
+++ b/packages/data-schemas/src/migrations/tenantIndexes.ts
@@ -24,8 +24,10 @@ const SUPERSEDED_INDEXES: Record<string, string[]> = {
     'appleId_1',
   ],
   roles: ['name_1'],
-  conversations: ['conversationId_1_user_1'],
-  messages: ['messageId_1_user_1'],
+  agents: ['id_1'],
+  conversations: ['conversationId_1', 'conversationId_1_user_1'],
+  messages: ['messageId_1', 'messageId_1_user_1'],
+  presets: ['presetId_1'],
   agentcategories: ['value_1'],
   accessroles: ['accessRoleId_1'],
   conversationtags: ['tag_1_user_1'],
diff --git a/packages/data-schemas/src/schema/agent.ts b/packages/data-schemas/src/schema/agent.ts
index 42a7ca5418..70734d0ceb 100644
--- a/packages/data-schemas/src/schema/agent.ts
+++ b/packages/data-schemas/src/schema/agent.ts
@@ -5,8 +5,6 @@ const agentSchema = new Schema<IAgent>(
   {
     id: {
       type: String,
-      index: true,
-      unique: true,
       required: true,
     },
     name: {
@@ -124,6 +122,7 @@ const agentSchema = new Schema<IAgent>(
   },
 );
 
+agentSchema.index({ id: 1, tenantId: 1 }, { unique: true });
 agentSchema.index({ updatedAt: -1, _id: 1 });
 agentSchema.index({ 'edges.to': 1 });
 
diff --git a/packages/data-schemas/src/schema/convo.ts b/packages/data-schemas/src/schema/convo.ts
index 9ed8949e9c..c8f394935a 100644
--- a/packages/data-schemas/src/schema/convo.ts
+++ b/packages/data-schemas/src/schema/convo.ts
@@ -6,7 +6,6 @@ const convoSchema: Schema<IConversation> = new Schema(
   {
     conversationId: {
       type: String,
-      unique: true,
       required: true,
       index: true,
       meiliIndex: true,
diff --git a/packages/data-schemas/src/schema/message.ts b/packages/data-schemas/src/schema/message.ts
index ff3468918e..9879efae55 100644
--- a/packages/data-schemas/src/schema/message.ts
+++ b/packages/data-schemas/src/schema/message.ts
@@ -5,7 +5,6 @@ const messageSchema: Schema<IMessage> = new Schema(
   {
     messageId: {
       type: String,
-      unique: true,
       required: true,
       index: true,
       meiliIndex: true,
diff --git a/packages/data-schemas/src/schema/preset.ts b/packages/data-schemas/src/schema/preset.ts
index 33c217ea23..5af5163fd3 100644
--- a/packages/data-schemas/src/schema/preset.ts
+++ b/packages/data-schemas/src/schema/preset.ts
@@ -60,7 +60,6 @@ const presetSchema: Schema<IPreset> = new Schema(
   {
     presetId: {
       type: String,
-      unique: true,
       required: true,
       index: true,
     },
@@ -88,4 +87,6 @@ const presetSchema: Schema<IPreset> = new Schema(
   { timestamps: true },
 );
 
+presetSchema.index({ presetId: 1, tenantId: 1 }, { unique: true });
+
 export default presetSchema;
diff --git a/packages/data-schemas/src/utils/index.ts b/packages/data-schemas/src/utils/index.ts
index c071f4e827..17e43ac3ca 100644
--- a/packages/data-schemas/src/utils/index.ts
+++ b/packages/data-schemas/src/utils/index.ts
@@ -1,5 +1,6 @@
 export * from './principal';
 export * from './string';
 export * from './tempChatRetention';
+export { tenantSafeBulkWrite } from './tenantBulkWrite';
 export * from './transactions';
 export * from './objectId';
diff --git a/packages/data-schemas/src/utils/tenantBulkWrite.spec.ts b/packages/data-schemas/src/utils/tenantBulkWrite.spec.ts
new file mode 100644
index 0000000000..059868b8a1
--- /dev/null
+++ b/packages/data-schemas/src/utils/tenantBulkWrite.spec.ts
@@ -0,0 +1,376 @@
+import mongoose, { Schema } from 'mongoose';
+import { MongoMemoryServer } from 'mongodb-memory-server';
+import { tenantStorage, runAsSystem, SYSTEM_TENANT_ID } from '~/config/tenantContext';
+import { applyTenantIsolation, _resetStrictCache } from '~/models/plugins/tenantIsolation';
+import { tenantSafeBulkWrite, _resetBulkWriteStrictCache } from './tenantBulkWrite';
+
+let mongoServer: InstanceType<typeof MongoMemoryServer>;
+
+interface ITestDoc {
+  name: string;
+  value?: number;
+  tenantId?: string;
+}
+
+function createTestModel(suffix: string) {
+  const schema = new Schema<ITestDoc>({
+    name: { type: String, required: true },
+    value: { type: Number, default: 0 },
+    tenantId: { type: String, index: true },
+  });
+  applyTenantIsolation(schema);
+  const modelName = `TestBulkWrite_${suffix}_${Date.now()}`;
+  return mongoose.model<ITestDoc>(modelName, schema);
+}
+
+beforeAll(async () => {
+  mongoServer = await MongoMemoryServer.create();
+  await mongoose.connect(mongoServer.getUri());
+});
+
+afterAll(async () => {
+  await mongoose.disconnect();
+  await mongoServer.stop();
+});
+
+afterEach(() => {
+  delete process.env.TENANT_ISOLATION_STRICT;
+  _resetStrictCache();
+  _resetBulkWriteStrictCache();
+});
+
+describe('tenantSafeBulkWrite', () => {
+  describe('with tenant context', () => {
+    it('injects tenantId into updateOne filters', async () => {
+      const Model = createTestModel('updateOne');
+
+      // Seed data for two tenants
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'doc1', value: 1, tenantId: 'tenant-a' },
+          { name: 'doc1', value: 1, tenantId: 'tenant-b' },
+        ]);
+      });
+
+      // Update only tenant-a's doc
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            updateOne: {
+              filter: { name: 'doc1' },
+              update: { $set: { value: 99 } },
+            },
+          },
+        ]);
+      });
+
+      // Verify tenant-a was updated, tenant-b was not
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      const docA = docs.find((d) => d.tenantId === 'tenant-a');
+      const docB = docs.find((d) => d.tenantId === 'tenant-b');
+      expect(docA?.value).toBe(99);
+      expect(docB?.value).toBe(1);
+    });
+
+    it('injects tenantId into insertOne documents', async () => {
+      const Model = createTestModel('insertOne');
+
+      await tenantStorage.run({ tenantId: 'tenant-x' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            insertOne: {
+              document: { name: 'new-doc', value: 42 } as ITestDoc,
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      expect(docs).toHaveLength(1);
+      expect(docs[0].tenantId).toBe('tenant-x');
+      expect(docs[0].name).toBe('new-doc');
+    });
+
+    it('injects tenantId into deleteOne filters', async () => {
+      const Model = createTestModel('deleteOne');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'to-delete', tenantId: 'tenant-a' },
+          { name: 'to-delete', tenantId: 'tenant-b' },
+        ]);
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            deleteOne: {
+              filter: { name: 'to-delete' },
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      expect(docs).toHaveLength(1);
+      expect(docs[0].tenantId).toBe('tenant-b');
+    });
+
+    it('injects tenantId into updateMany filters', async () => {
+      const Model = createTestModel('updateMany');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'batch', value: 0, tenantId: 'tenant-a' },
+          { name: 'batch', value: 0, tenantId: 'tenant-a' },
+          { name: 'batch', value: 0, tenantId: 'tenant-b' },
+        ]);
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            updateMany: {
+              filter: { name: 'batch' },
+              update: { $set: { value: 5 } },
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      const tenantADocs = docs.filter((d) => d.tenantId === 'tenant-a');
+      const tenantBDocs = docs.filter((d) => d.tenantId === 'tenant-b');
+      expect(tenantADocs.every((d) => d.value === 5)).toBe(true);
+      expect(tenantBDocs[0].value).toBe(0);
+    });
+  });
+
+  describe('with SYSTEM_TENANT_ID', () => {
+    it('skips tenantId injection (cross-tenant operation)', async () => {
+      const Model = createTestModel('system');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'sys-doc', value: 0, tenantId: 'tenant-a' },
+          { name: 'sys-doc', value: 0, tenantId: 'tenant-b' },
+        ]);
+      });
+
+      // System context should update ALL docs regardless of tenant
+      await runAsSystem(async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            updateMany: {
+              filter: { name: 'sys-doc' },
+              update: { $set: { value: 100 } },
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      expect(docs.every((d) => d.value === 100)).toBe(true);
+    });
+  });
+
+  describe('with SYSTEM_TENANT_ID in strict mode', () => {
+    it('does not throw when runAsSystem is used in strict mode', async () => {
+      process.env.TENANT_ISOLATION_STRICT = 'true';
+      _resetBulkWriteStrictCache();
+
+      const Model = createTestModel('systemStrict');
+
+      await runAsSystem(async () => {
+        await Model.create({ name: 'strict-sys', value: 0 });
+      });
+
+      await expect(
+        runAsSystem(async () =>
+          tenantSafeBulkWrite(Model, [
+            {
+              updateOne: {
+                filter: { name: 'strict-sys' },
+                update: { $set: { value: 42 } },
+              },
+            },
+          ]),
+        ),
+      ).resolves.toBeDefined();
+    });
+  });
+
+  describe('deleteMany and replaceOne', () => {
+    it('injects tenantId into deleteMany filters', async () => {
+      const Model = createTestModel('deleteMany');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'batch-del', value: 0, tenantId: 'tenant-a' },
+          { name: 'batch-del', value: 0, tenantId: 'tenant-a' },
+          { name: 'batch-del', value: 0, tenantId: 'tenant-b' },
+        ]);
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [{ deleteMany: { filter: { name: 'batch-del' } } }]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      expect(docs).toHaveLength(1);
+      expect(docs[0].tenantId).toBe('tenant-b');
+    });
+
+    it('injects tenantId into replaceOne filter and replacement', async () => {
+      const Model = createTestModel('replaceOne');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'to-replace', value: 1, tenantId: 'tenant-a' },
+          { name: 'to-replace', value: 1, tenantId: 'tenant-b' },
+        ]);
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            replaceOne: {
+              filter: { name: 'to-replace' },
+              replacement: { name: 'replaced', value: 99 },
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).sort({ name: 1 }).lean());
+      const replaced = docs.find((d) => d.name === 'replaced');
+      const untouched = docs.find((d) => d.tenantId === 'tenant-b');
+      expect(replaced?.value).toBe(99);
+      expect(replaced?.tenantId).toBe('tenant-a');
+      expect(untouched?.value).toBe(1);
+    });
+
+    it('replaceOne overwrites a conflicting tenantId in the replacement document', async () => {
+      const Model = createTestModel('replaceOverwrite');
+
+      await runAsSystem(async () => {
+        await Model.create({ name: 'conflict', value: 1, tenantId: 'tenant-a' });
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-a' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            replaceOne: {
+              filter: { name: 'conflict' },
+              replacement: { name: 'conflict', value: 2, tenantId: 'tenant-evil' } as ITestDoc,
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).lean());
+      expect(docs).toHaveLength(1);
+      expect(docs[0].tenantId).toBe('tenant-a');
+      expect(docs[0].value).toBe(2);
+    });
+  });
+
+  describe('edge cases', () => {
+    it('handles empty ops array', async () => {
+      const Model = createTestModel('emptyOps');
+      const result = await tenantStorage.run({ tenantId: 'tenant-x' }, async () =>
+        tenantSafeBulkWrite(Model, []),
+      );
+      expect(result.insertedCount).toBe(0);
+      expect(result.modifiedCount).toBe(0);
+    });
+  });
+
+  describe('without tenant context', () => {
+    it('passes through in non-strict mode', async () => {
+      const Model = createTestModel('noCtx');
+
+      await runAsSystem(async () => {
+        await Model.create({ name: 'no-ctx', value: 0 });
+      });
+
+      // No ALS context — non-strict should pass through
+      const result = await tenantSafeBulkWrite(Model, [
+        {
+          updateOne: {
+            filter: { name: 'no-ctx' },
+            update: { $set: { value: 10 } },
+          },
+        },
+      ]);
+
+      expect(result.modifiedCount).toBe(1);
+    });
+
+    it('throws in strict mode', async () => {
+      process.env.TENANT_ISOLATION_STRICT = 'true';
+      _resetBulkWriteStrictCache();
+
+      const Model = createTestModel('strict');
+
+      await expect(
+        tenantSafeBulkWrite(Model, [
+          {
+            updateOne: {
+              filter: { name: 'any' },
+              update: { $set: { value: 1 } },
+            },
+          },
+        ]),
+      ).rejects.toThrow('bulkWrite on TestBulkWrite_strict');
+    });
+  });
+
+  describe('mixed operations', () => {
+    it('handles a batch of mixed insert, update, delete operations', async () => {
+      const Model = createTestModel('mixed');
+
+      await runAsSystem(async () => {
+        await Model.create([
+          { name: 'existing1', value: 1, tenantId: 'tenant-m' },
+          { name: 'to-remove', value: 2, tenantId: 'tenant-m' },
+          { name: 'existing1', value: 1, tenantId: 'tenant-other' },
+        ]);
+      });
+
+      await tenantStorage.run({ tenantId: 'tenant-m' }, async () => {
+        await tenantSafeBulkWrite(Model, [
+          {
+            insertOne: {
+              document: { name: 'new-item', value: 10 } as ITestDoc,
+            },
+          },
+          {
+            updateOne: {
+              filter: { name: 'existing1' },
+              update: { $set: { value: 50 } },
+            },
+          },
+          {
+            deleteOne: {
+              filter: { name: 'to-remove' },
+            },
+          },
+        ]);
+      });
+
+      const docs = await runAsSystem(async () => Model.find({}).sort({ name: 1 }).lean());
+
+      // tenant-other's doc should be untouched
+      const otherDoc = docs.find((d) => d.tenantId === 'tenant-other' && d.name === 'existing1');
+      expect(otherDoc?.value).toBe(1);
+
+      // tenant-m: existing1 updated, to-remove deleted, new-item inserted
+      const tenantMDocs = docs.filter((d) => d.tenantId === 'tenant-m');
+      expect(tenantMDocs).toHaveLength(2);
+      expect(tenantMDocs.find((d) => d.name === 'existing1')?.value).toBe(50);
+      expect(tenantMDocs.find((d) => d.name === 'new-item')?.value).toBe(10);
+      expect(tenantMDocs.find((d) => d.name === 'to-remove')).toBeUndefined();
+    });
+  });
+});
diff --git a/packages/data-schemas/src/utils/tenantBulkWrite.ts b/packages/data-schemas/src/utils/tenantBulkWrite.ts
new file mode 100644
index 0000000000..16ef5fa057
--- /dev/null
+++ b/packages/data-schemas/src/utils/tenantBulkWrite.ts
@@ -0,0 +1,109 @@
+import type { AnyBulkWriteOperation, Model, MongooseBulkWriteOptions } from 'mongoose';
+import type { BulkWriteResult } from 'mongodb';
+import { getTenantId, SYSTEM_TENANT_ID } from '~/config/tenantContext';
+import logger from '~/config/winston';
+
+let _strictMode: boolean | undefined;
+
+function isStrict(): boolean {
+  return (_strictMode ??= process.env.TENANT_ISOLATION_STRICT === 'true');
+}
+
+/** Resets the cached strict-mode flag. Exposed for test teardown only. */
+export function _resetBulkWriteStrictCache(): void {
+  _strictMode = undefined;
+}
+
+/**
+ * Tenant-safe wrapper around Mongoose `Model.bulkWrite()`.
+ *
+ * Mongoose's `bulkWrite` does not trigger schema-level middleware hooks, so the
+ * `applyTenantIsolation` plugin cannot intercept it. This wrapper injects the
+ * current ALS tenant context into every operation's filter and/or document
+ * before delegating to the native `bulkWrite`.
+ *
+ * Behavior:
+ * - **tenantId present** (normal request): injects `{ tenantId }` into every
+ *   operation filter (updateOne, deleteOne, replaceOne) and document (insertOne).
+ * - **SYSTEM_TENANT_ID**: skips injection (cross-tenant system operation).
+ * - **No tenantId + strict mode**: throws (fail-closed, same as the plugin).
+ * - **No tenantId + non-strict**: passes through without injection (backward compat).
+ */
+export async function tenantSafeBulkWrite<T>(
+  model: Model<T>,
+  ops: AnyBulkWriteOperation[],
+  options?: MongooseBulkWriteOptions,
+): Promise<BulkWriteResult> {
+  const tenantId = getTenantId();
+
+  if (!tenantId) {
+    if (isStrict()) {
+      throw new Error(
+        `[TenantIsolation] bulkWrite on ${model.modelName} attempted without tenant context in strict mode`,
+      );
+    }
+    return model.bulkWrite(ops, options);
+  }
+
+  if (tenantId === SYSTEM_TENANT_ID) {
+    return model.bulkWrite(ops, options);
+  }
+
+  const injected = ops.map((op) => injectTenantId(op, tenantId));
+  return model.bulkWrite(injected, options);
+}
+
+/**
+ * Injects `tenantId` into a single bulk-write operation.
+ * Returns a new operation object — does not mutate the original.
+ */
+function injectTenantId(op: AnyBulkWriteOperation, tenantId: string): AnyBulkWriteOperation {
+  if ('insertOne' in op) {
+    return {
+      insertOne: {
+        document: { ...op.insertOne.document, tenantId },
+      },
+    };
+  }
+
+  if ('updateOne' in op) {
+    const { filter, ...rest } = op.updateOne;
+    return { updateOne: { ...rest, filter: { ...filter, tenantId } } };
+  }
+
+  if ('updateMany' in op) {
+    const { filter, ...rest } = op.updateMany;
+    return { updateMany: { ...rest, filter: { ...filter, tenantId } } };
+  }
+
+  if ('deleteOne' in op) {
+    const { filter, ...rest } = op.deleteOne;
+    return { deleteOne: { ...rest, filter: { ...filter, tenantId } } };
+  }
+
+  if ('deleteMany' in op) {
+    const { filter, ...rest } = op.deleteMany;
+    return { deleteMany: { ...rest, filter: { ...filter, tenantId } } };
+  }
+
+  if ('replaceOne' in op) {
+    const { filter, replacement, ...rest } = op.replaceOne;
+    return {
+      replaceOne: {
+        ...rest,
+        filter: { ...filter, tenantId },
+        replacement: { ...replacement, tenantId },
+      },
+    };
+  }
+
+  if (isStrict()) {
+    throw new Error(
+      '[TenantIsolation] Unknown bulkWrite operation type in strict mode — refusing to pass through without tenant injection',
+    );
+  }
+  logger.warn(
+    '[tenantSafeBulkWrite] Unknown bulk op type, passing through without tenant injection',
+  );
+  return op;
+}