diff --git a/.gitignore b/.gitignore
index e302d15a46..d775e70a26 100644
--- a/.gitignore
+++ b/.gitignore
@@ -137,6 +137,7 @@ helm/**/.values.yaml
 
 # AI Assistants
 /.claude/
+/.codex/
 /.cursor/
 /.copilot/
 /.aider/
diff --git a/api/package.json b/api/package.json
index 86b0f22c0b..bad538a5fc 100644
--- a/api/package.json
+++ b/api/package.json
@@ -118,7 +118,7 @@
   },
   "devDependencies": {
     "jest": "^30.2.0",
-    "mongodb-memory-server": "^10.1.4",
+    "mongodb-memory-server": "^11.0.1",
     "nodemon": "^3.0.3",
     "supertest": "^7.1.0"
   }
diff --git a/api/server/routes/__tests__/mcp.spec.js b/api/server/routes/__tests__/mcp.spec.js
index f194f361d3..9e3ed7a351 100644
--- a/api/server/routes/__tests__/mcp.spec.js
+++ b/api/server/routes/__tests__/mcp.spec.js
@@ -311,6 +311,87 @@ describe('MCP Routes', () => {
       expect(response.headers.location).toBe(`${basePath}/oauth/error?error=access_denied`);
     });
 
+    describe('OAuth error callback failFlow', () => {
+      it('should fail the flow when OAuth error is received with valid CSRF cookie', async () => {
+        const flowId = 'test-user-id:test-server';
+        const mockFlowManager = {
+          failFlow: jest.fn().mockResolvedValue(true),
+        };
+
+        getLogStores.mockReturnValueOnce({});
+        require('~/config').getFlowStateManager.mockReturnValueOnce(mockFlowManager);
+        MCPOAuthHandler.resolveStateToFlowId.mockResolvedValueOnce(flowId);
+
+        const csrfToken = generateTestCsrfToken(flowId);
+        const response = await request(app)
+          .get('/api/mcp/test-server/oauth/callback')
+          .set('Cookie', [`oauth_csrf=${csrfToken}`])
+          .query({
+            error: 'invalid_client',
+            state: flowId,
+          });
+        const basePath = getBasePath();
+
+        expect(response.status).toBe(302);
+        expect(response.headers.location).toBe(`${basePath}/oauth/error?error=invalid_client`);
+        expect(mockFlowManager.failFlow).toHaveBeenCalledWith(
+          flowId,
+          'mcp_oauth',
+          'invalid_client',
+        );
+      });
+
+      it('should fail the flow when OAuth error is received with valid session cookie', async () => {
+        const flowId = 'test-user-id:test-server';
+        const mockFlowManager = {
+          failFlow: jest.fn().mockResolvedValue(true),
+        };
+
+        getLogStores.mockReturnValueOnce({});
+        require('~/config').getFlowStateManager.mockReturnValueOnce(mockFlowManager);
+        MCPOAuthHandler.resolveStateToFlowId.mockResolvedValueOnce(flowId);
+
+        const sessionToken = generateTestCsrfToken('test-user-id');
+        const response = await request(app)
+          .get('/api/mcp/test-server/oauth/callback')
+          .set('Cookie', [`oauth_session=${sessionToken}`])
+          .query({
+            error: 'invalid_client',
+            state: flowId,
+          });
+        const basePath = getBasePath();
+
+        expect(response.status).toBe(302);
+        expect(response.headers.location).toBe(`${basePath}/oauth/error?error=invalid_client`);
+        expect(mockFlowManager.failFlow).toHaveBeenCalledWith(
+          flowId,
+          'mcp_oauth',
+          'invalid_client',
+        );
+      });
+
+      it('should NOT fail the flow when OAuth error is received without cookies (DoS prevention)', async () => {
+        const flowId = 'test-user-id:test-server';
+        const mockFlowManager = {
+          failFlow: jest.fn(),
+        };
+
+        getLogStores.mockReturnValueOnce({});
+        require('~/config').getFlowStateManager.mockReturnValueOnce(mockFlowManager);
+        MCPOAuthHandler.resolveStateToFlowId.mockResolvedValueOnce(flowId);
+
+        const response = await request(app).get('/api/mcp/test-server/oauth/callback').query({
+          error: 'invalid_client',
+          state: flowId,
+        });
+        const basePath = getBasePath();
+
+        expect(response.status).toBe(302);
+        expect(response.headers.location).toBe(`${basePath}/oauth/error?error=invalid_client`);
+        expect(mockFlowManager.failFlow).not.toHaveBeenCalled();
+      });
+    });
+
     it('should redirect to error page when code is missing', async () => {
       const response = await request(app).get('/api/mcp/test-server/oauth/callback').query({
         state: 'test-user-id:test-server',
diff --git a/api/server/routes/__tests__/roles.spec.js b/api/server/routes/__tests__/roles.spec.js
new file mode 100644
index 0000000000..e78965d460
--- /dev/null
+++ b/api/server/routes/__tests__/roles.spec.js
@@ -0,0 +1,155 @@
+const express = require('express');
+const request = require('supertest');
+const { SystemRoles, roleDefaults } = require('librechat-data-provider');
+
+const mockGetRoleByName = jest.fn();
+const mockHasCapability = jest.fn();
+
+jest.mock('~/server/middleware', () => ({
+  requireJwtAuth: (_req, _res, next) => next(),
+}));
+
+jest.mock('~/server/middleware/roles/capabilities', () => ({
+  hasCapability: (...args) => mockHasCapability(...args),
+  requireCapability: () => (_req, _res, next) => next(),
+}));
+
+jest.mock('~/models', () => ({
+  getRoleByName: (...args) => mockGetRoleByName(...args),
+  updateRoleByName: jest.fn(),
+}));
+
+const rolesRouter = require('../roles');
+
+function createApp(user) {
+  const app = express();
+  app.use(express.json());
+  app.use((req, _res, next) => {
+    req.user = user;
+    next();
+  });
+  app.use('/api/roles', rolesRouter);
+  return app;
+}
+
+const staffRole = {
+  name: 'STAFF',
+  permissions: {
+    PROMPTS: { USE: true, CREATE: false },
+  },
+};
+
+const userRole = roleDefaults[SystemRoles.USER];
+const adminRole = roleDefaults[SystemRoles.ADMIN];
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  mockHasCapability.mockResolvedValue(false);
+  mockGetRoleByName.mockResolvedValue(null);
+});
+
+describe('GET /api/roles/:roleName — isOwnRole authorization', () => {
+  it('allows a custom role user to fetch their own role', async () => {
+    mockGetRoleByName.mockResolvedValue(staffRole);
+    const app = createApp({ id: 'u1', role: 'STAFF' });
+
+    const res = await request(app).get('/api/roles/STAFF');
+
+    expect(res.status).toBe(200);
+    expect(res.body.name).toBe('STAFF');
+    expect(mockGetRoleByName).toHaveBeenCalledWith('STAFF', '-_id -__v');
+  });
+
+  it('returns 403 when a custom role user requests a different custom role', async () => {
+    const app = createApp({ id: 'u1', role: 'STAFF' });
+
+    const res = await request(app).get('/api/roles/MANAGER');
+
+    expect(res.status).toBe(403);
+    expect(mockGetRoleByName).not.toHaveBeenCalled();
+  });
+
+  it('returns 403 when a custom role user requests ADMIN', async () => {
+    const app = createApp({ id: 'u1', role: 'STAFF' });
+
+    const res = await request(app).get('/api/roles/ADMIN');
+
+    expect(res.status).toBe(403);
+    expect(mockGetRoleByName).not.toHaveBeenCalled();
+  });
+
+  it('allows USER to fetch the USER role (roleDefaults key)', async () => {
+    mockGetRoleByName.mockResolvedValue(userRole);
+    const app = createApp({ id: 'u1', role: SystemRoles.USER });
+
+    const res = await request(app).get(`/api/roles/${SystemRoles.USER}`);
+
+    expect(res.status).toBe(200);
+  });
+
+  it('returns 403 when USER requests the ADMIN role', async () => {
+    const app = createApp({ id: 'u1', role: SystemRoles.USER });
+
+    const res = await request(app).get(`/api/roles/${SystemRoles.ADMIN}`);
+
+    expect(res.status).toBe(403);
+  });
+
+  it('allows ADMIN user to fetch their own ADMIN role via isOwnRole', async () => {
+    mockHasCapability.mockResolvedValue(false);
+    mockGetRoleByName.mockResolvedValue(adminRole);
+    const app = createApp({ id: 'u1', role: SystemRoles.ADMIN });
+
+    const res = await request(app).get(`/api/roles/${SystemRoles.ADMIN}`);
+
+    expect(res.status).toBe(200);
+  });
+
+  it('allows any user with READ_ROLES capability to fetch any role', async () => {
+    mockHasCapability.mockResolvedValue(true);
+    mockGetRoleByName.mockResolvedValue(staffRole);
+    const app = createApp({ id: 'u1', role: SystemRoles.USER });
+
+    const res = await request(app).get('/api/roles/STAFF');
+
+    expect(res.status).toBe(200);
+    expect(res.body.name).toBe('STAFF');
+  });
+
+  it('returns 404 when the requested role does not exist', async () => {
+    mockGetRoleByName.mockResolvedValue(null);
+    const app = createApp({ id: 'u1', role: 'GHOST' });
+
+    const res = await request(app).get('/api/roles/GHOST');
+
+    expect(res.status).toBe(404);
+  });
+
+  it('returns 500 when getRoleByName throws', async () => {
+    mockGetRoleByName.mockRejectedValue(new Error('db error'));
+    const app = createApp({ id: 'u1', role: SystemRoles.USER });
+
+    const res = await request(app).get(`/api/roles/${SystemRoles.USER}`);
+
+    expect(res.status).toBe(500);
+  });
+
+  it('returns 403 for prototype property names like constructor (no prototype pollution)', async () => {
+    const app = createApp({ id: 'u1', role: 'STAFF' });
+
+    const res = await request(app).get('/api/roles/constructor');
+
+    expect(res.status).toBe(403);
+    expect(mockGetRoleByName).not.toHaveBeenCalled();
+  });
+
+  it('treats hasCapability failure as no capability (does not 500)', async () => {
+    mockHasCapability.mockRejectedValue(new Error('capability check failed'));
+    const app = createApp({ id: 'u1', role: 'STAFF' });
+    mockGetRoleByName.mockResolvedValue(staffRole);
+
+    const res = await request(app).get('/api/roles/STAFF');
+
+    expect(res.status).toBe(200);
+  });
+});
diff --git a/api/server/routes/admin/auth.js b/api/server/routes/admin/auth.js
index 72f23b7d52..07306ac4db 100644
--- a/api/server/routes/admin/auth.js
+++ b/api/server/routes/admin/auth.js
@@ -3,7 +3,12 @@ const passport = require('passport');
 const crypto = require('node:crypto');
 const { CacheKeys } = require('librechat-data-provider');
 const { logger, SystemCapabilities } = require('@librechat/data-schemas');
-const { getAdminPanelUrl, exchangeAdminCode, createSetBalanceConfig } = require('@librechat/api');
+const {
+  getAdminPanelUrl,
+  exchangeAdminCode,
+  createSetBalanceConfig,
+  storeAndStripChallenge,
+} = require('@librechat/api');
 const { loginController } = require('~/server/controllers/auth/LoginController');
 const { requireCapability } = require('~/server/middleware/roles/capabilities');
 const { createOAuthHandler } = require('~/server/controllers/auth/oauth');
@@ -73,11 +78,6 @@ router.get('/oauth/openid/check', (req, res) => {
   res.status(200).json({ message: 'OpenID check successful' });
 });
 
-/** PKCE challenge cache TTL: 5 minutes (enough for user to authenticate with IdP) */
-const PKCE_CHALLENGE_TTL = 5 * 60 * 1000;
-/** Regex pattern for valid PKCE challenges: 64 hex characters (SHA-256 hex digest) */
-const PKCE_CHALLENGE_PATTERN = /^[a-f0-9]{64}$/;
-
 /**
  * Generates a random hex state string for OAuth flows.
  * @returns {string} A 32-byte random hex string.
@@ -86,27 +86,6 @@ function generateState() {
   return crypto.randomBytes(32).toString('hex');
 }
 
-/**
- * Stores a PKCE challenge in cache keyed by state.
- * @param {string} state - The OAuth state value.
- * @param {string | undefined} codeChallenge - The PKCE code_challenge from query params.
- * @param {string} provider - Provider name for logging.
- * @returns {Promise<boolean>} True if stored successfully or no challenge provided.
- */
-async function storePkceChallenge(state, codeChallenge, provider) {
-  if (typeof codeChallenge !== 'string' || !PKCE_CHALLENGE_PATTERN.test(codeChallenge)) {
-    return true;
-  }
-  try {
-    const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
-    await cache.set(`pkce:${state}`, codeChallenge, PKCE_CHALLENGE_TTL);
-    return true;
-  } catch (err) {
-    logger.error(`[admin/oauth/${provider}] Failed to store PKCE challenge:`, err);
-    return false;
-  }
-}
-
 /**
  * Middleware to retrieve PKCE challenge from cache using the OAuth state.
  * Reads state from req.oauthState (set by a preceding middleware).
@@ -148,7 +127,8 @@ function retrievePkceChallenge(provider) {
 
 router.get('/oauth/openid', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'openid');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'openid');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/openid/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -185,7 +165,8 @@ router.get(
 
 router.get('/oauth/saml', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'saml');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'saml');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/saml/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -222,7 +203,8 @@ router.post(
 
 router.get('/oauth/google', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'google');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'google');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/google/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -260,7 +242,8 @@ router.get(
 
 router.get('/oauth/github', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'github');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'github');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/github/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -298,7 +281,8 @@ router.get(
 
 router.get('/oauth/discord', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'discord');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'discord');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/discord/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -336,7 +320,8 @@ router.get(
 
 router.get('/oauth/facebook', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'facebook');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'facebook');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/facebook/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
@@ -374,7 +359,8 @@ router.get(
 
 router.get('/oauth/apple', async (req, res, next) => {
   const state = generateState();
-  const stored = await storePkceChallenge(state, req.query.code_challenge, 'apple');
+  const cache = getLogStores(CacheKeys.ADMIN_OAUTH_EXCHANGE);
+  const stored = await storeAndStripChallenge(cache, req, state, 'apple');
   if (!stored) {
     return res.redirect(
       `${getAdminPanelUrl()}/auth/apple/callback?error=pkce_store_failed&error_description=Failed+to+store+PKCE+challenge`,
diff --git a/api/server/routes/mcp.js b/api/server/routes/mcp.js
index c6496ad4b4..b747e6f5ed 100644
--- a/api/server/routes/mcp.js
+++ b/api/server/routes/mcp.js
@@ -149,6 +149,29 @@ router.get('/:serverName/oauth/callback', async (req, res) => {
 
     if (oauthError) {
       logger.error('[MCP OAuth] OAuth error received', { error: oauthError });
+      // Gate failFlow behind callback validation to prevent DoS via leaked state
+      if (state && typeof state === 'string') {
+        try {
+          const flowsCache = getLogStores(CacheKeys.FLOWS);
+          const flowManager = getFlowStateManager(flowsCache);
+          const flowId = await MCPOAuthHandler.resolveStateToFlowId(state, flowManager);
+          if (flowId) {
+            const flowParts = flowId.split(':');
+            const [flowUserId] = flowParts;
+            const hasCsrf = validateOAuthCsrf(req, res, flowId, OAUTH_CSRF_COOKIE_PATH);
+            const hasSession = !hasCsrf && validateOAuthSession(req, flowUserId);
+            if (hasCsrf || hasSession) {
+              await flowManager.failFlow(flowId, 'mcp_oauth', String(oauthError));
+              logger.debug('[MCP OAuth] Marked flow as FAILED with OAuth error', {
+                flowId,
+                error: oauthError,
+              });
+            }
+          }
+        } catch (err) {
+          logger.debug('[MCP OAuth] Could not mark flow as failed', err);
+        }
+      }
       return res.redirect(
         `${basePath}/oauth/error?error=${encodeURIComponent(String(oauthError))}`,
       );
diff --git a/api/server/routes/roles.js b/api/server/routes/roles.js
index 25ee47854d..456d144af1 100644
--- a/api/server/routes/roles.js
+++ b/api/server/routes/roles.js
@@ -71,9 +71,7 @@ const createPermissionUpdateHandler = (permissionKey) => {
   const config = permissionConfigs[permissionKey];
 
   return async (req, res) => {
-    const { roleName: _r } = req.params;
-    // TODO: TEMP, use a better parsing for roleName
-    const roleName = _r.toUpperCase();
+    const { roleName } = req.params;
     const updates = req.body;
 
     try {
@@ -110,9 +108,7 @@ const createPermissionUpdateHandler = (permissionKey) => {
  * Get a specific role by name
  */
 router.get('/:roleName', async (req, res) => {
-  const { roleName: _r } = req.params;
-  // TODO: TEMP, use a better parsing for roleName
-  const roleName = _r.toUpperCase();
+  const { roleName } = req.params;
 
   try {
     let hasReadRoles = false;
@@ -121,7 +117,9 @@ router.get('/:roleName', async (req, res) => {
     } catch (err) {
       logger.warn(`[GET /roles/:roleName] capability check failed: ${err.message}`);
     }
-    if (!hasReadRoles && (roleName === SystemRoles.ADMIN || !roleDefaults[roleName])) {
+    const isOwnRole = req.user?.role === roleName;
+    const isDefaultRole = Object.hasOwn(roleDefaults, roleName);
+    if (!hasReadRoles && !isOwnRole && (roleName === SystemRoles.ADMIN || !isDefaultRole)) {
       return res.status(403).send({ message: 'Unauthorized' });
     }
 
diff --git a/api/server/services/MCP.js b/api/server/services/MCP.js
index dbb44740a9..ccff184d4d 100644
--- a/api/server/services/MCP.js
+++ b/api/server/services/MCP.js
@@ -23,7 +23,7 @@ const {
   getFlowStateManager,
   getMCPManager,
 } = require('~/config');
-const { findToken, createToken, updateToken } = require('~/models');
+const { findToken, createToken, updateToken, deleteTokens } = require('~/models');
 const { getGraphApiToken } = require('./GraphTokenService');
 const { reinitMCPServer } = require('./Tools/mcp');
 const { getAppConfig } = require('./Config');
@@ -644,6 +644,7 @@ function createToolInstance({
           findToken,
           createToken,
           updateToken,
+          deleteTokens,
         },
         oauthStart,
         oauthEnd,
diff --git a/client/package.json b/client/package.json
index 5fe9cddcc7..f041629cbb 100644
--- a/client/package.json
+++ b/client/package.json
@@ -81,7 +81,7 @@
     "lodash": "^4.17.23",
     "lucide-react": "^0.394.0",
     "match-sorter": "^8.1.0",
-    "mermaid": "^11.13.0",
+    "mermaid": "^11.14.0",
     "micromark-extension-llm-math": "^3.1.0",
     "qrcode.react": "^4.2.0",
     "rc-input-number": "^7.4.2",
diff --git a/client/src/components/Chat/Messages/Message.tsx b/client/src/components/Chat/Messages/Message.tsx
index 53aef812fc..fc2a79fca0 100644
--- a/client/src/components/Chat/Messages/Message.tsx
+++ b/client/src/components/Chat/Messages/Message.tsx
@@ -47,7 +47,6 @@ export default function Message(props: TMessageProps) {
         </div>
       </MessageContainer>
       <MultiMessage
-        key={messageId}
         messageId={messageId}
         conversation={conversation}
         messagesTree={children ?? []}
diff --git a/client/src/components/Chat/Messages/MessageIcon.tsx b/client/src/components/Chat/Messages/MessageIcon.tsx
index d63e0d2071..1c4401c338 100644
--- a/client/src/components/Chat/Messages/MessageIcon.tsx
+++ b/client/src/components/Chat/Messages/MessageIcon.tsx
@@ -4,7 +4,7 @@ import type { Assistant, Agent } from 'librechat-data-provider';
 import type { TMessageIcon } from '~/common';
 import ConvoIconURL from '~/components/Endpoints/ConvoIconURL';
 import { useGetEndpointsQuery } from '~/data-provider';
-import { getIconEndpoint, logger } from '~/utils';
+import { getIconEndpoint } from '~/utils';
 import Icon from '~/components/Endpoints/Icon';
 
 type MessageIconProps = {
@@ -19,38 +19,27 @@ type MessageIconProps = {
  * this component renders display properties only, not identity-derived content.
  */
 export function arePropsEqual(prev: MessageIconProps, next: MessageIconProps): boolean {
-  if (prev.iconData?.endpoint !== next.iconData?.endpoint) {
-    return false;
-  }
-  if (prev.iconData?.model !== next.iconData?.model) {
-    return false;
-  }
-  if (prev.iconData?.iconURL !== next.iconData?.iconURL) {
-    return false;
-  }
-  if (prev.iconData?.modelLabel !== next.iconData?.modelLabel) {
-    return false;
-  }
-  if (prev.iconData?.isCreatedByUser !== next.iconData?.isCreatedByUser) {
-    return false;
-  }
-  if (prev.agent?.name !== next.agent?.name) {
-    return false;
-  }
-  if (prev.agent?.avatar?.filepath !== next.agent?.avatar?.filepath) {
-    return false;
-  }
-  if (prev.assistant?.name !== next.assistant?.name) {
-    return false;
-  }
-  if (prev.assistant?.metadata?.avatar !== next.assistant?.metadata?.avatar) {
-    return false;
+  const checks: [unknown, unknown][] = [
+    [prev.iconData?.endpoint, next.iconData?.endpoint],
+    [prev.iconData?.model, next.iconData?.model],
+    [prev.iconData?.iconURL, next.iconData?.iconURL],
+    [prev.iconData?.modelLabel, next.iconData?.modelLabel],
+    [prev.iconData?.isCreatedByUser, next.iconData?.isCreatedByUser],
+    [prev.agent?.name, next.agent?.name],
+    [prev.agent?.avatar?.filepath, next.agent?.avatar?.filepath],
+    [prev.assistant?.name, next.assistant?.name],
+    [prev.assistant?.metadata?.avatar, next.assistant?.metadata?.avatar],
+  ];
+
+  for (const [prevVal, nextVal] of checks) {
+    if (prevVal !== nextVal) {
+      return false;
+    }
   }
   return true;
 }
 
 const MessageIcon = memo(({ iconData, assistant, agent }: MessageIconProps) => {
-  logger.log('icon_data', iconData, assistant, agent);
   const { data: endpointsConfig } = useGetEndpointsQuery();
 
   const agentName = agent?.name ?? '';
diff --git a/client/src/components/Chat/Messages/MessageParts.tsx b/client/src/components/Chat/Messages/MessageParts.tsx
index 3d13fa6ae0..2d0e3d512b 100644
--- a/client/src/components/Chat/Messages/MessageParts.tsx
+++ b/client/src/components/Chat/Messages/MessageParts.tsx
@@ -179,7 +179,6 @@ export default function Message(props: TMessageProps) {
         </div>
       </div>
       <MultiMessage
-        key={messageId}
         messageId={messageId}
         conversation={conversation}
         messagesTree={children ?? []}
diff --git a/client/src/components/Chat/Messages/MessagesView.tsx b/client/src/components/Chat/Messages/MessagesView.tsx
index ca4a0cce85..b4f555d189 100644
--- a/client/src/components/Chat/Messages/MessagesView.tsx
+++ b/client/src/components/Chat/Messages/MessagesView.tsx
@@ -62,7 +62,6 @@ function MessagesViewContent({
                 <>
                   <div ref={screenshotTargetRef}>
                     <MultiMessage
-                      key={conversationId}
                       messagesTree={_messagesTree}
                       messageId={conversationId ?? null}
                       setCurrentEditId={setCurrentEditId}
diff --git a/client/src/components/Chat/Messages/MultiMessage.tsx b/client/src/components/Chat/Messages/MultiMessage.tsx
index 13eb2d143f..4a561045f5 100644
--- a/client/src/components/Chat/Messages/MultiMessage.tsx
+++ b/client/src/components/Chat/Messages/MultiMessage.tsx
@@ -39,47 +39,40 @@ export default function MultiMessage({
     return null;
   }
 
-  const message = messagesTree[messagesTree.length - siblingIdx - 1] as TMessage | undefined;
+  const currentSiblingIdx = messagesTree.length - siblingIdx - 1;
+  const message = messagesTree[currentSiblingIdx] as TMessage | undefined;
 
   if (!message) {
     return null;
   }
 
+  /**
+   * No explicit key — React uses positional reconciliation since MultiMessage
+   * always renders exactly one child at this position.
+   *
+   * Both messageId and parentMessageId change during the SSE lifecycle
+   * (client UUID → createdHandler ID → server ID), so neither can serve as a
+   * stable key. Using either caused React to unmount/remount the entire subtree
+   * on each SSE event, destroying memoized state and causing visible flickering.
+   *
+   * Without a key, React reuses the component instance and updates props in place.
+   * The memo comparators on ContentRender/MessageRender handle field-level diffing,
+   * and sibling switches work correctly because the message prop changes entirely.
+   */
+  const sharedProps = {
+    message,
+    currentEditId,
+    setCurrentEditId,
+    siblingIdx: currentSiblingIdx,
+    siblingCount: messagesTree.length,
+    setSiblingIdx: setSiblingIdxRev,
+  };
+
   if (isAssistantsEndpoint(message.endpoint) && message.content) {
-    return (
-      <MessageParts
-        key={message.messageId}
-        message={message}
-        currentEditId={currentEditId}
-        setCurrentEditId={setCurrentEditId}
-        siblingIdx={messagesTree.length - siblingIdx - 1}
-        siblingCount={messagesTree.length}
-        setSiblingIdx={setSiblingIdxRev}
-      />
-    );
+    return <MessageParts {...sharedProps} />;
   } else if (message.content) {
-    return (
-      <MessageContent
-        key={message.messageId}
-        message={message}
-        currentEditId={currentEditId}
-        setCurrentEditId={setCurrentEditId}
-        siblingIdx={messagesTree.length - siblingIdx - 1}
-        siblingCount={messagesTree.length}
-        setSiblingIdx={setSiblingIdxRev}
-      />
-    );
+    return <MessageContent {...sharedProps} />;
   }
 
-  return (
-    <Message
-      key={message.messageId}
-      message={message}
-      currentEditId={currentEditId}
-      setCurrentEditId={setCurrentEditId}
-      siblingIdx={messagesTree.length - siblingIdx - 1}
-      siblingCount={messagesTree.length}
-      setSiblingIdx={setSiblingIdxRev}
-    />
-  );
+  return <Message {...sharedProps} />;
 }
diff --git a/client/src/components/Chat/Messages/__tests__/MessageIcon.render.test.tsx b/client/src/components/Chat/Messages/__tests__/MessageIcon.render.test.tsx
new file mode 100644
index 0000000000..c19142494a
--- /dev/null
+++ b/client/src/components/Chat/Messages/__tests__/MessageIcon.render.test.tsx
@@ -0,0 +1,169 @@
+import React from 'react';
+import { render } from '@testing-library/react';
+import { EModelEndpoint } from 'librechat-data-provider';
+import type { Agent } from 'librechat-data-provider';
+import type { TMessageIcon } from '~/common';
+
+jest.mock('librechat-data-provider', () => ({
+  ...jest.requireActual('librechat-data-provider'),
+  getEndpointField: jest.fn(() => ''),
+}));
+jest.mock('~/data-provider', () => ({
+  useGetEndpointsQuery: jest.fn(() => ({ data: {} })),
+}));
+jest.mock('~/utils', () => ({
+  getIconEndpoint: jest.fn(() => 'agents'),
+}));
+
+const iconRenderCount = { current: 0 };
+
+jest.mock('~/components/Endpoints/ConvoIconURL', () => {
+  const ConvoIconURL = (props: Record<string, unknown>) => {
+    iconRenderCount.current += 1;
+    return <div data-testid="convo-icon-url" data-icon-url={props.iconURL as string} />;
+  };
+  ConvoIconURL.displayName = 'ConvoIconURL';
+  return { __esModule: true, default: ConvoIconURL };
+});
+jest.mock('~/components/Endpoints/Icon', () => {
+  const Icon = (props: Record<string, unknown>) => {
+    iconRenderCount.current += 1;
+    return <div data-testid="icon" data-icon-url={props.iconURL as string} />;
+  };
+  Icon.displayName = 'Icon';
+  return { __esModule: true, default: Icon };
+});
+
+import MessageIcon from '../MessageIcon';
+
+const makeAgent = (overrides?: Partial<Agent>): Agent =>
+  ({
+    id: 'agent_123',
+    name: 'GitHub Agent',
+    avatar: { filepath: '/images/agent-avatar.png' },
+    ...overrides,
+  }) as Agent;
+
+const baseIconData: TMessageIcon = {
+  endpoint: EModelEndpoint.agents,
+  model: 'agent_123',
+  iconURL: undefined,
+  modelLabel: 'GitHub Agent',
+  isCreatedByUser: false,
+};
+
+describe('MessageIcon render cycles', () => {
+  beforeEach(() => {
+    iconRenderCount.current = 0;
+  });
+
+  it('renders once on initial mount', () => {
+    render(<MessageIcon iconData={baseIconData} agent={makeAgent()} />);
+    expect(iconRenderCount.current).toBe(1);
+  });
+
+  it('does not re-render when parent re-renders with same field values but new object references', () => {
+    const agent = makeAgent();
+    const { rerender } = render(<MessageIcon iconData={baseIconData} agent={agent} />);
+    iconRenderCount.current = 0;
+
+    rerender(<MessageIcon iconData={{ ...baseIconData }} agent={makeAgent()} />);
+
+    expect(iconRenderCount.current).toBe(0);
+  });
+
+  it('does not re-render when agent object reference changes but name and avatar are the same', () => {
+    const agent1 = makeAgent();
+    const { rerender } = render(<MessageIcon iconData={baseIconData} agent={agent1} />);
+    iconRenderCount.current = 0;
+
+    const agent2 = makeAgent({ id: 'agent_456' });
+    rerender(<MessageIcon iconData={baseIconData} agent={agent2} />);
+
+    expect(iconRenderCount.current).toBe(0);
+  });
+
+  it('re-renders when agent avatar filepath changes', () => {
+    const agent1 = makeAgent();
+    const { rerender } = render(<MessageIcon iconData={baseIconData} agent={agent1} />);
+    iconRenderCount.current = 0;
+
+    const agent2 = makeAgent({ avatar: { filepath: '/images/new-avatar.png' } });
+    rerender(<MessageIcon iconData={baseIconData} agent={agent2} />);
+
+    expect(iconRenderCount.current).toBe(1);
+  });
+
+  it('re-renders when agent goes from undefined to defined (name changes from undefined to string)', () => {
+    const { rerender } = render(<MessageIcon iconData={baseIconData} agent={undefined} />);
+    iconRenderCount.current = 0;
+
+    rerender(<MessageIcon iconData={baseIconData} agent={makeAgent()} />);
+
+    expect(iconRenderCount.current).toBe(1);
+  });
+
+  describe('simulates message lifecycle', () => {
+    it('renders exactly twice during new message + streaming start: initial render + modelLabel update', () => {
+      const initialIconData: TMessageIcon = {
+        endpoint: EModelEndpoint.agents,
+        model: 'agent_123',
+        iconURL: undefined,
+        modelLabel: '',
+        isCreatedByUser: false,
+      };
+      const agent = makeAgent();
+
+      const { rerender } = render(<MessageIcon iconData={initialIconData} agent={agent} />);
+
+      const streamingIconData: TMessageIcon = {
+        ...initialIconData,
+        modelLabel: 'GitHub Agent',
+      };
+
+      rerender(<MessageIcon iconData={streamingIconData} agent={agent} />);
+
+      expect(iconRenderCount.current).toBe(2);
+    });
+
+    it('does NOT re-render on subsequent streaming chunks (content changes, isSubmitting stays true)', () => {
+      const iconData: TMessageIcon = {
+        endpoint: EModelEndpoint.agents,
+        model: 'agent_123',
+        iconURL: undefined,
+        modelLabel: 'GitHub Agent',
+        isCreatedByUser: false,
+      };
+      const agent = makeAgent();
+
+      const { rerender } = render(<MessageIcon iconData={iconData} agent={agent} />);
+      iconRenderCount.current = 0;
+
+      for (let i = 0; i < 5; i++) {
+        rerender(<MessageIcon iconData={{ ...iconData }} agent={makeAgent()} />);
+      }
+
+      expect(iconRenderCount.current).toBe(0);
+    });
+
+    it('does NOT re-render when agentsMap context updates with same agent data', () => {
+      const iconData: TMessageIcon = {
+        endpoint: EModelEndpoint.agents,
+        model: 'agent_123',
+        iconURL: undefined,
+        modelLabel: 'GitHub Agent',
+        isCreatedByUser: false,
+      };
+
+      const agent1 = makeAgent();
+      const { rerender } = render(<MessageIcon iconData={iconData} agent={agent1} />);
+      iconRenderCount.current = 0;
+
+      const agent2 = makeAgent();
+      expect(agent1).not.toBe(agent2);
+      rerender(<MessageIcon iconData={iconData} agent={agent2} />);
+
+      expect(iconRenderCount.current).toBe(0);
+    });
+  });
+});
diff --git a/client/src/components/Messages/MessageContent.tsx b/client/src/components/Messages/MessageContent.tsx
index 977e397022..67865ed397 100644
--- a/client/src/components/Messages/MessageContent.tsx
+++ b/client/src/components/Messages/MessageContent.tsx
@@ -48,7 +48,6 @@ export default function MessageContent(props: TMessageProps) {
         </div>
       </MessageContainer>
       <MultiMessage
-        key={messageId}
         messageId={messageId}
         conversation={conversation}
         messagesTree={children ?? []}
diff --git a/client/src/components/Sharing/PeoplePickerAdminSettings.tsx b/client/src/components/Sharing/PeoplePickerAdminSettings.tsx
index 38d44ad311..5f334f3764 100644
--- a/client/src/components/Sharing/PeoplePickerAdminSettings.tsx
+++ b/client/src/components/Sharing/PeoplePickerAdminSettings.tsx
@@ -1,8 +1,8 @@
-import { useMemo, useEffect, useState } from 'react';
+import { useEffect, useState } from 'react';
 import * as Ariakit from '@ariakit/react';
 import { ShieldEllipsis } from 'lucide-react';
 import { useForm, Controller } from 'react-hook-form';
-import { Permissions, SystemRoles, roleDefaults, PermissionTypes } from 'librechat-data-provider';
+import { Permissions, SystemRoles, PermissionTypes } from 'librechat-data-provider';
 import {
   Button,
   Switch,
@@ -15,7 +15,7 @@ import {
 } from '@librechat/client';
 import type { Control, UseFormSetValue, UseFormGetValues } from 'react-hook-form';
 import { useUpdatePeoplePickerPermissionsMutation } from '~/data-provider';
-import { useLocalize, useAuthContext } from '~/hooks';
+import { useLocalize, useAuthContext, useRoleSelector } from '~/hooks';
 
 type FormValues = {
   [Permissions.VIEW_USERS]: boolean;
@@ -70,7 +70,7 @@ const LabelController: React.FC<LabelControllerProps> = ({
 const PeoplePickerAdminSettings = () => {
   const localize = useLocalize();
   const { showToast } = useToastContext();
-  const { user, roles } = useAuthContext();
+  const { user } = useAuthContext();
   const { mutate, isLoading } = useUpdatePeoplePickerPermissionsMutation({
     onSuccess: () => {
       showToast({ status: 'success', message: localize('com_ui_saved') });
@@ -81,15 +81,14 @@ const PeoplePickerAdminSettings = () => {
   });
 
   const [isRoleMenuOpen, setIsRoleMenuOpen] = useState(false);
-  const [selectedRole, setSelectedRole] = useState<SystemRoles>(SystemRoles.USER);
-
-  const defaultValues = useMemo(() => {
-    const rolePerms = roles?.[selectedRole]?.permissions;
-    if (rolePerms) {
-      return rolePerms[PermissionTypes.PEOPLE_PICKER];
-    }
-    return roleDefaults[selectedRole].permissions[PermissionTypes.PEOPLE_PICKER];
-  }, [roles, selectedRole]);
+  const {
+    selectedRole,
+    isSelectedCustomRole,
+    isCustomRoleLoading,
+    isCustomRoleError,
+    defaultValues,
+    roleDropdownItems,
+  } = useRoleSelector(PermissionTypes.PEOPLE_PICKER);
 
   const {
     reset,
@@ -100,17 +99,15 @@ const PeoplePickerAdminSettings = () => {
     formState: { isSubmitting },
   } = useForm<FormValues>({
     mode: 'onChange',
-    defaultValues,
+    defaultValues: defaultValues as FormValues,
   });
 
   useEffect(() => {
-    const value = roles?.[selectedRole]?.permissions?.[PermissionTypes.PEOPLE_PICKER];
-    if (value) {
-      reset(value);
-    } else {
-      reset(roleDefaults[selectedRole].permissions[PermissionTypes.PEOPLE_PICKER]);
+    if (isSelectedCustomRole && (isCustomRoleLoading || isCustomRoleError)) {
+      return;
     }
-  }, [roles, selectedRole, reset]);
+    reset(defaultValues as FormValues);
+  }, [isSelectedCustomRole, isCustomRoleLoading, isCustomRoleError, defaultValues, reset]);
 
   if (user?.role !== SystemRoles.ADMIN) {
     return null;
@@ -138,21 +135,6 @@ const PeoplePickerAdminSettings = () => {
     mutate({ roleName: selectedRole, updates: data });
   };
 
-  const roleDropdownItems = [
-    {
-      label: SystemRoles.USER,
-      onClick: () => {
-        setSelectedRole(SystemRoles.USER);
-      },
-    },
-    {
-      label: SystemRoles.ADMIN,
-      onClick: () => {
-        setSelectedRole(SystemRoles.ADMIN);
-      },
-    },
-  ];
-
   return (
     <OGDialog>
       <OGDialogTrigger asChild>
@@ -179,7 +161,7 @@ const PeoplePickerAdminSettings = () => {
               isOpen={isRoleMenuOpen}
               setIsOpen={setIsRoleMenuOpen}
               trigger={
-                <Ariakit.MenuButton className="inline-flex w-1/4 items-center justify-center rounded-lg border border-border-light bg-transparent px-2 py-1 text-text-primary transition-all ease-in-out hover:bg-surface-tertiary">
+                <Ariakit.MenuButton className="inline-flex min-w-[6rem] items-center justify-center rounded-lg border border-border-light bg-transparent px-2 py-1 text-text-primary transition-all ease-in-out hover:bg-surface-tertiary">
                   {selectedRole}
                 </Ariakit.MenuButton>
               }
@@ -207,7 +189,11 @@ const PeoplePickerAdminSettings = () => {
               <button
                 type="button"
                 onClick={handleSubmit(onSubmit)}
-                disabled={isSubmitting || isLoading}
+                disabled={
+                  isSubmitting ||
+                  isLoading ||
+                  (isSelectedCustomRole && (isCustomRoleLoading || isCustomRoleError))
+                }
                 className="btn rounded bg-green-500 font-bold text-white transition-all hover:bg-green-600"
               >
                 {localize('com_ui_save')}
diff --git a/client/src/components/UnifiedSidebar/ConversationsSection.tsx b/client/src/components/UnifiedSidebar/ConversationsSection.tsx
index c02741d038..4cd487ad3d 100644
--- a/client/src/components/UnifiedSidebar/ConversationsSection.tsx
+++ b/client/src/components/UnifiedSidebar/ConversationsSection.tsx
@@ -120,7 +120,7 @@ const ConversationsSection = memo(() => {
             <BookmarkNav tags={tags} setTags={setTags} />
           </Suspense>
         )}
-        <SearchBar isSmallScreen={isSmallScreen} />
+        {search.enabled && <SearchBar isSmallScreen={isSmallScreen} />}
       </div>
       {isSmallScreen && (
         <div
diff --git a/client/src/components/ui/AdminSettingsDialog.tsx b/client/src/components/ui/AdminSettingsDialog.tsx
index 321f88b06b..d2e8dc19c2 100644
--- a/client/src/components/ui/AdminSettingsDialog.tsx
+++ b/client/src/components/ui/AdminSettingsDialog.tsx
@@ -1,8 +1,8 @@
-import { useMemo, useEffect, useState } from 'react';
+import { useEffect, useState } from 'react';
 import * as Ariakit from '@ariakit/react';
 import { ShieldEllipsis } from 'lucide-react';
 import { useForm, Controller } from 'react-hook-form';
-import { Permissions, SystemRoles, roleDefaults, PermissionTypes } from 'librechat-data-provider';
+import { Permissions, SystemRoles } from 'librechat-data-provider';
 import {
   OGDialog,
   OGDialogTitle,
@@ -13,8 +13,9 @@ import {
   DropdownPopup,
 } from '@librechat/client';
 import type { Control, UseFormSetValue, UseFormGetValues } from 'react-hook-form';
+import type { PermissionTypes } from 'librechat-data-provider';
 import type { TranslationKeys } from '~/hooks/useLocalize';
-import { useLocalize, useAuthContext } from '~/hooks';
+import { useLocalize, useAuthContext, useRoleSelector } from '~/hooks';
 
 type FormValues = Record<Permissions, boolean>;
 
@@ -34,7 +35,7 @@ export interface AdminSettingsDialogProps {
   menuId: string;
   /** Mutation function and loading state from the permission update hook */
   mutation: {
-    mutate: (data: { roleName: SystemRoles; updates: Record<Permissions, boolean> }) => void;
+    mutate: (data: { roleName: string; updates: Record<Permissions, boolean> }) => void;
     isLoading: boolean;
   };
   /** Whether to show the admin access warning when ADMIN role and USE permission is displayed (default: true) */
@@ -108,18 +109,18 @@ const AdminSettingsDialog: React.FC<AdminSettingsDialogProps> = ({
   extraContent,
 }) => {
   const localize = useLocalize();
-  const { user, roles } = useAuthContext();
+  const { user } = useAuthContext();
   const { mutate, isLoading } = mutation;
 
   const [isRoleMenuOpen, setIsRoleMenuOpen] = useState(false);
-  const [selectedRole, setSelectedRole] = useState<SystemRoles>(SystemRoles.USER);
-
-  const defaultValues = useMemo(() => {
-    if (roles?.[selectedRole]?.permissions) {
-      return roles[selectedRole]?.permissions[permissionType];
-    }
-    return roleDefaults[selectedRole].permissions[permissionType];
-  }, [roles, selectedRole, permissionType]);
+  const {
+    selectedRole,
+    isSelectedCustomRole,
+    isCustomRoleLoading,
+    isCustomRoleError,
+    defaultValues,
+    roleDropdownItems,
+  } = useRoleSelector(permissionType);
 
   const {
     reset,
@@ -134,12 +135,11 @@ const AdminSettingsDialog: React.FC<AdminSettingsDialogProps> = ({
   });
 
   useEffect(() => {
-    if (roles?.[selectedRole]?.permissions?.[permissionType]) {
-      reset(roles[selectedRole]?.permissions[permissionType]);
-    } else {
-      reset(roleDefaults[selectedRole].permissions[permissionType]);
+    if (isSelectedCustomRole && (isCustomRoleLoading || isCustomRoleError)) {
+      return;
     }
-  }, [roles, selectedRole, reset, permissionType]);
+    reset(defaultValues);
+  }, [isSelectedCustomRole, isCustomRoleLoading, isCustomRoleError, defaultValues, reset]);
 
   if (user?.role !== SystemRoles.ADMIN) {
     return null;
@@ -149,21 +149,6 @@ const AdminSettingsDialog: React.FC<AdminSettingsDialogProps> = ({
     mutate({ roleName: selectedRole, updates: data });
   };
 
-  const roleDropdownItems = [
-    {
-      label: SystemRoles.USER,
-      onClick: () => {
-        setSelectedRole(SystemRoles.USER);
-      },
-    },
-    {
-      label: SystemRoles.ADMIN,
-      onClick: () => {
-        setSelectedRole(SystemRoles.ADMIN);
-      },
-    },
-  ];
-
   const defaultTrigger = (
     <Button
       size="sm"
@@ -199,7 +184,7 @@ const AdminSettingsDialog: React.FC<AdminSettingsDialogProps> = ({
               isOpen={isRoleMenuOpen}
               setIsOpen={setIsRoleMenuOpen}
               trigger={
-                <Ariakit.MenuButton className="inline-flex w-1/4 items-center justify-center rounded-lg border border-border-light bg-transparent px-2 py-1 text-text-primary transition-all ease-in-out hover:bg-surface-tertiary">
+                <Ariakit.MenuButton className="inline-flex min-w-[6rem] items-center justify-center rounded-lg border border-border-light bg-transparent px-2 py-1 text-text-primary transition-all ease-in-out hover:bg-surface-tertiary">
                   {selectedRole}
                 </Ariakit.MenuButton>
               }
@@ -257,7 +242,11 @@ const AdminSettingsDialog: React.FC<AdminSettingsDialogProps> = ({
               <Button
                 type="submit"
                 variant="submit"
-                disabled={isSubmitting || isLoading}
+                disabled={
+                  isSubmitting ||
+                  isLoading ||
+                  (isSelectedCustomRole && (isCustomRoleLoading || isCustomRoleError))
+                }
                 aria-label={localize('com_ui_save')}
               >
                 {localize('com_ui_save')}
diff --git a/client/src/data-provider/roles.ts b/client/src/data-provider/roles.ts
index 356d9bd145..88c79433f5 100644
--- a/client/src/data-provider/roles.ts
+++ b/client/src/data-provider/roles.ts
@@ -29,6 +29,18 @@ export const useGetRole = (
   });
 };
 
+export const useListRoles = (
+  config?: UseQueryOptions<t.ListRolesResponse>,
+): QueryObserverResult<t.ListRolesResponse> => {
+  return useQuery<t.ListRolesResponse>([QueryKeys.rolesList], () => dataService.listRoles(), {
+    refetchOnWindowFocus: false,
+    refetchOnReconnect: false,
+    refetchOnMount: false,
+    retry: false,
+    ...config,
+  });
+};
+
 export const useUpdatePromptPermissionsMutation = (
   options?: t.UpdatePromptPermOptions,
 ): UseMutationResult<
diff --git a/client/src/hooks/AuthContext.tsx b/client/src/hooks/AuthContext.tsx
index 2fb7dd7760..18ea90a46d 100644
--- a/client/src/hooks/AuthContext.tsx
+++ b/client/src/hooks/AuthContext.tsx
@@ -14,6 +14,7 @@ import {
   apiBaseUrl,
   SystemRoles,
   setTokenHeader,
+  isSystemRoleName,
   buildLoginRedirectUrl,
 } from 'librechat-data-provider';
 import type * as t from 'librechat-data-provider';
@@ -47,12 +48,18 @@ const AuthContextProvider = ({
   const [isAuthenticated, setIsAuthenticated] = useState<boolean>(false);
   const setQueriesEnabled = useSetRecoilState<boolean>(store.queriesEnabled);
 
+  const userRoleName = user?.role ?? '';
+  const isCustomRole = isAuthenticated && !!user?.role && !isSystemRoleName(user.role);
+
   const { data: userRole = null } = useGetRole(SystemRoles.USER, {
     enabled: !!(isAuthenticated && (user?.role ?? '')),
   });
   const { data: adminRole = null } = useGetRole(SystemRoles.ADMIN, {
     enabled: !!(isAuthenticated && user?.role === SystemRoles.ADMIN),
   });
+  const { data: customRole = null } = useGetRole(isCustomRole ? userRoleName : '_', {
+    enabled: isCustomRole,
+  });
 
   const navigate = useNavigate();
 
@@ -267,11 +274,22 @@ const AuthContextProvider = ({
       roles: {
         [SystemRoles.USER]: userRole,
         [SystemRoles.ADMIN]: adminRole,
+        ...(isCustomRole && customRole ? { [userRoleName]: customRole } : {}),
       },
       isAuthenticated,
     }),
 
-    [user, error, isAuthenticated, token, userRole, adminRole],
+    [
+      user,
+      error,
+      isAuthenticated,
+      token,
+      userRole,
+      adminRole,
+      isCustomRole,
+      userRoleName,
+      customRole,
+    ],
   );
 
   return <AuthContext.Provider value={memoedValue}>{children}</AuthContext.Provider>;
diff --git a/client/src/hooks/Input/useAutoSave.spec.ts b/client/src/hooks/Input/useAutoSave.spec.ts
new file mode 100644
index 0000000000..5a5f6b423a
--- /dev/null
+++ b/client/src/hooks/Input/useAutoSave.spec.ts
@@ -0,0 +1,110 @@
+jest.mock('recoil', () => ({
+  ...jest.requireActual('recoil'),
+  useRecoilValue: jest.fn(),
+}));
+
+jest.mock('~/store', () => ({
+  saveDrafts: { key: 'saveDrafts', default: true },
+}));
+
+jest.mock('~/Providers', () => ({
+  useChatFormContext: jest.fn(),
+}));
+
+jest.mock('~/data-provider', () => ({
+  useGetFiles: jest.fn(),
+}));
+
+jest.mock('~/utils', () => ({
+  ...jest.requireActual('~/utils'),
+  getDraft: jest.fn(),
+  setDraft: jest.fn(),
+  clearDraft: jest.fn(),
+  clearAllDrafts: jest.fn(),
+}));
+
+import React from 'react';
+import { renderHook, act } from '@testing-library/react';
+import { useRecoilValue } from 'recoil';
+import { useChatFormContext } from '~/Providers';
+import { useGetFiles } from '~/data-provider';
+import { getDraft, setDraft } from '~/utils';
+import store from '~/store';
+import { useAutoSave } from '~/hooks';
+
+const mockSetValue = jest.fn();
+const mockGetDraft = getDraft as jest.Mock;
+const mockSetDraft = setDraft as jest.Mock;
+
+const makeTextAreaRef = (value = '') =>
+  ({
+    current: { value, addEventListener: jest.fn(), removeEventListener: jest.fn() },
+  }) as unknown as React.RefObject<HTMLTextAreaElement>;
+
+beforeEach(() => {
+  (useRecoilValue as jest.Mock).mockImplementation((atom) => {
+    if (atom === store.saveDrafts) return true;
+    return undefined;
+  });
+  (useChatFormContext as jest.Mock).mockReturnValue({ setValue: mockSetValue });
+  (useGetFiles as jest.Mock).mockReturnValue({ data: [] });
+  mockGetDraft.mockReturnValue('');
+});
+
+describe('useAutoSave — conversation switching', () => {
+  it('clears the textarea when switching to a conversation with no draft', () => {
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({
+          conversationId,
+          textAreaRef: makeTextAreaRef(),
+          files: new Map(),
+          setFiles: jest.fn(),
+        }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetValue).toHaveBeenLastCalledWith('text', '');
+  });
+
+  it('restores the saved draft when switching to a conversation with one', () => {
+    mockGetDraft.mockImplementation((id: string) => (id === 'convo-2' ? 'Hello, world!' : ''));
+
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({
+          conversationId,
+          textAreaRef: makeTextAreaRef(),
+          files: new Map(),
+          setFiles: jest.fn(),
+        }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetValue).toHaveBeenLastCalledWith('text', 'Hello, world!');
+  });
+
+  it('saves the current textarea content before switching away', () => {
+    const textAreaRef = makeTextAreaRef('draft in progress');
+
+    const { rerender } = renderHook(
+      ({ conversationId }: { conversationId: string }) =>
+        useAutoSave({ conversationId, textAreaRef, files: new Map(), setFiles: jest.fn() }),
+      { initialProps: { conversationId: 'convo-1' } },
+    );
+
+    act(() => {
+      rerender({ conversationId: 'convo-2' });
+    });
+
+    expect(mockSetDraft).toHaveBeenCalledWith({ id: 'convo-1', value: 'draft in progress' });
+  });
+});
diff --git a/client/src/hooks/Input/useAutoSave.ts b/client/src/hooks/Input/useAutoSave.ts
index 95cd0d1933..b0c588db46 100644
--- a/client/src/hooks/Input/useAutoSave.ts
+++ b/client/src/hooks/Input/useAutoSave.ts
@@ -73,11 +73,7 @@ export const useAutoSave = ({
 
   const restoreText = useCallback(
     (id: string) => {
-      const savedDraft = getDraft(id);
-      if (!savedDraft) {
-        return;
-      }
-      setValue('text', savedDraft);
+      setValue('text', getDraft(id) ?? '');
     },
     [setValue],
   );
diff --git a/client/src/hooks/__tests__/AuthContext.spec.tsx b/client/src/hooks/__tests__/AuthContext.spec.tsx
index 10a0ee3340..58f8eca768 100644
--- a/client/src/hooks/__tests__/AuthContext.spec.tsx
+++ b/client/src/hooks/__tests__/AuthContext.spec.tsx
@@ -64,13 +64,20 @@ jest.mock('~/data-provider', () => ({
     error: null,
   })),
   useGetRole: jest.fn(() => ({ data: null })),
+  useListRoles: jest.fn(() => ({ data: undefined })),
 }));
 
 const authConfig: TAuthConfig = { loginRedirect: '/login', test: true };
 
 function TestConsumer() {
   const ctx = useAuthContext();
-  return <div data-testid="consumer" data-authenticated={ctx.isAuthenticated} />;
+  return (
+    <div
+      data-testid="consumer"
+      data-authenticated={ctx.isAuthenticated}
+      data-roles={JSON.stringify(ctx.roles ?? {})}
+    />
+  );
 }
 
 function renderProvider() {
@@ -445,3 +452,130 @@ describe('AuthContextProvider — logout error handling', () => {
     jest.useRealTimers();
   });
 });
+
+describe('AuthContextProvider — custom role detection and fetching', () => {
+  const mockUseGetRole = jest.requireMock('~/data-provider').useGetRole;
+  const staffPermissions = {
+    name: 'STAFF',
+    permissions: { PROMPTS: { USE: true, CREATE: false } },
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    sessionStorage.clear();
+  });
+
+  afterEach(() => {
+    sessionStorage.clear();
+    window.history.replaceState({}, '', '/');
+  });
+
+  it('calls useGetRole with the custom role name and enabled: true for custom role users', () => {
+    jest.useFakeTimers();
+
+    renderProviderLive();
+
+    const [, refreshOptions] = mockRefreshMutate.mock.calls[0] as [
+      unknown,
+      { onSuccess: (data: unknown) => void },
+    ];
+
+    act(() => {
+      refreshOptions.onSuccess({ user: { id: '1', role: 'STAFF' }, token: 'tok' });
+    });
+    act(() => {
+      jest.advanceTimersByTime(100);
+    });
+
+    const staffCalls = mockUseGetRole.mock.calls.filter(([name]: [string]) => name === 'STAFF');
+    expect(staffCalls.length).toBeGreaterThan(0);
+    const lastStaffCall = staffCalls[staffCalls.length - 1];
+    expect(lastStaffCall[1]).toEqual(expect.objectContaining({ enabled: true }));
+
+    jest.useRealTimers();
+  });
+
+  it('calls useGetRole with enabled: false for USER role users', () => {
+    jest.useFakeTimers();
+
+    renderProviderLive();
+
+    const [, refreshOptions] = mockRefreshMutate.mock.calls[0] as [
+      unknown,
+      { onSuccess: (data: unknown) => void },
+    ];
+
+    act(() => {
+      refreshOptions.onSuccess({ user: { id: '1', role: 'USER' }, token: 'tok' });
+    });
+    act(() => {
+      jest.advanceTimersByTime(100);
+    });
+
+    const sentinelCalls = mockUseGetRole.mock.calls.filter(([name]: [string]) => name === '_');
+    expect(sentinelCalls.length).toBeGreaterThan(0);
+    for (const call of sentinelCalls) {
+      expect(call[1]).toEqual(expect.objectContaining({ enabled: false }));
+    }
+
+    jest.useRealTimers();
+  });
+
+  it('calls useGetRole with enabled: false for ADMIN role users', () => {
+    jest.useFakeTimers();
+
+    renderProviderLive();
+
+    const [, refreshOptions] = mockRefreshMutate.mock.calls[0] as [
+      unknown,
+      { onSuccess: (data: unknown) => void },
+    ];
+
+    act(() => {
+      refreshOptions.onSuccess({ user: { id: '1', role: 'ADMIN' }, token: 'tok' });
+    });
+    act(() => {
+      jest.advanceTimersByTime(100);
+    });
+
+    const sentinelCalls = mockUseGetRole.mock.calls.filter(([name]: [string]) => name === '_');
+    expect(sentinelCalls.length).toBeGreaterThan(0);
+    for (const call of sentinelCalls) {
+      expect(call[1]).toEqual(expect.objectContaining({ enabled: false }));
+    }
+
+    jest.useRealTimers();
+  });
+
+  it('includes custom role data in the roles context map when loaded', () => {
+    jest.useFakeTimers();
+    mockUseGetRole.mockImplementation((name: string, opts?: { enabled?: boolean }) => {
+      if (name === 'STAFF' && opts?.enabled) {
+        return { data: staffPermissions };
+      }
+      return { data: null };
+    });
+
+    const { getByTestId } = renderProviderLive();
+
+    const [, refreshOptions] = mockRefreshMutate.mock.calls[0] as [
+      unknown,
+      { onSuccess: (data: unknown) => void },
+    ];
+
+    act(() => {
+      refreshOptions.onSuccess({ user: { id: '1', role: 'STAFF' }, token: 'tok' });
+    });
+    act(() => {
+      jest.advanceTimersByTime(100);
+    });
+
+    const rolesAttr = getByTestId('consumer').getAttribute('data-roles') ?? '{}';
+    const roles = JSON.parse(rolesAttr);
+    expect(roles).toHaveProperty('STAFF');
+    expect(roles.STAFF).toEqual(staffPermissions);
+
+    mockUseGetRole.mockReturnValue({ data: null });
+    jest.useRealTimers();
+  });
+});
diff --git a/client/src/hooks/index.ts b/client/src/hooks/index.ts
index 4b58e434c2..41a928578a 100644
--- a/client/src/hooks/index.ts
+++ b/client/src/hooks/index.ts
@@ -37,3 +37,4 @@ export { default as useTextToSpeech } from './Input/useTextToSpeech';
 export { default as useGenerationsByLatest } from './useGenerationsByLatest';
 export { default as useLocalizedConfig } from './useLocalizedConfig';
 export { default as useResourcePermissions } from './useResourcePermissions';
+export { useRoleSelector } from './useRoleSelector';
diff --git a/client/src/hooks/useRoleSelector.ts b/client/src/hooks/useRoleSelector.ts
new file mode 100644
index 0000000000..55bfeef278
--- /dev/null
+++ b/client/src/hooks/useRoleSelector.ts
@@ -0,0 +1,64 @@
+import { useMemo, useState, useCallback } from 'react';
+import { SystemRoles, roleDefaults, isSystemRoleName } from 'librechat-data-provider';
+import type { PermissionTypes, TRole } from 'librechat-data-provider';
+import { useGetRole, useListRoles } from '~/data-provider';
+import { useAuthContext } from './AuthContext';
+
+export function useRoleSelector(permissionType: PermissionTypes) {
+  const { user, roles } = useAuthContext();
+  const [selectedRole, setSelectedRole] = useState<string>(SystemRoles.USER);
+
+  const { data: roleList } = useListRoles({
+    enabled: user?.role === SystemRoles.ADMIN,
+  });
+
+  const isSelectedCustomRole = !isSystemRoleName(selectedRole);
+
+  const {
+    data: customRoleData = null,
+    isLoading: isCustomRoleLoading,
+    isError: isCustomRoleError,
+  } = useGetRole(isSelectedCustomRole ? selectedRole : '_', { enabled: isSelectedCustomRole });
+
+  const resolvePermissions = useCallback(
+    (role: string, customData: TRole | null) => {
+      const isCustom = !isSystemRoleName(role);
+      if (isCustom && customData?.permissions?.[permissionType]) {
+        return customData.permissions[permissionType];
+      }
+      if (!isCustom && roles?.[role]?.permissions?.[permissionType]) {
+        return roles[role]?.permissions[permissionType];
+      }
+      const defaults = !isCustom
+        ? roleDefaults[role as SystemRoles]
+        : roleDefaults[SystemRoles.USER];
+      return defaults.permissions[permissionType];
+    },
+    [roles, permissionType],
+  );
+
+  const defaultValues = useMemo(
+    () => resolvePermissions(selectedRole, customRoleData),
+    [resolvePermissions, selectedRole, customRoleData],
+  );
+
+  const availableRoleNames = useMemo(() => {
+    const names = roleList?.roles?.map((r) => r.name);
+    return names?.length ? names : [SystemRoles.USER, SystemRoles.ADMIN];
+  }, [roleList]);
+
+  const roleDropdownItems = useMemo(
+    () => availableRoleNames.map((role) => ({ label: role, onClick: () => setSelectedRole(role) })),
+    [availableRoleNames],
+  );
+
+  return {
+    selectedRole,
+    setSelectedRole,
+    isSelectedCustomRole,
+    isCustomRoleLoading,
+    isCustomRoleError,
+    defaultValues,
+    roleDropdownItems,
+  };
+}
diff --git a/librechat.example.yaml b/librechat.example.yaml
index b841f812ad..671c653534 100644
--- a/librechat.example.yaml
+++ b/librechat.example.yaml
@@ -2,7 +2,7 @@
 # https://www.librechat.ai/docs/configuration/librechat_yaml
 
 # Configuration version (required)
-version: 1.3.6
+version: 1.3.7
 
 # Cache settings: Set to true to enable caching
 cache: true
@@ -80,10 +80,8 @@ interface:
 
       By using the Website, you acknowledge that you have read these Terms of Service and agree to be bound by them.
 
-  endpointsMenu: true
   modelSelect: true
   parameters: true
-  sidePanel: true
   presets: true
   prompts:
     use: true
diff --git a/package-lock.json b/package-lock.json
index d5c8e47490..d7ec011391 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -133,7 +133,7 @@
       },
       "devDependencies": {
         "jest": "^30.2.0",
-        "mongodb-memory-server": "^10.1.4",
+        "mongodb-memory-server": "^11.0.1",
         "nodemon": "^3.0.3",
         "supertest": "^7.1.0"
       }
@@ -447,7 +447,7 @@
         "lodash": "^4.17.23",
         "lucide-react": "^0.394.0",
         "match-sorter": "^8.1.0",
-        "mermaid": "^11.13.0",
+        "mermaid": "^11.14.0",
         "micromark-extension-llm-math": "^3.1.0",
         "qrcode.react": "^4.2.0",
         "rc-input-number": "^7.4.2",
@@ -6895,6 +6895,12 @@
         "lodash-es": "4.17.23"
       }
     },
+    "node_modules/@chevrotain/cst-dts-gen/node_modules/lodash-es": {
+      "version": "4.17.23",
+      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.17.23.tgz",
+      "integrity": "sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==",
+      "license": "MIT"
+    },
     "node_modules/@chevrotain/gast": {
       "version": "11.1.2",
       "resolved": "https://registry.npmjs.org/@chevrotain/gast/-/gast-11.1.2.tgz",
@@ -6905,6 +6911,12 @@
         "lodash-es": "4.17.23"
       }
     },
+    "node_modules/@chevrotain/gast/node_modules/lodash-es": {
+      "version": "4.17.23",
+      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.17.23.tgz",
+      "integrity": "sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==",
+      "license": "MIT"
+    },
     "node_modules/@chevrotain/regexp-to-ast": {
       "version": "11.1.2",
       "resolved": "https://registry.npmjs.org/@chevrotain/regexp-to-ast/-/regexp-to-ast-11.1.2.tgz",
@@ -11944,9 +11956,9 @@
       }
     },
     "node_modules/@mermaid-js/parser": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/@mermaid-js/parser/-/parser-1.0.1.tgz",
-      "integrity": "sha512-opmV19kN1JsK0T6HhhokHpcVkqKpF+x2pPDKKM2ThHtZAB5F4PROopk0amuVYK5qMrIA4erzpNm8gmPNJgMDxQ==",
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/@mermaid-js/parser/-/parser-1.1.0.tgz",
+      "integrity": "sha512-gxK9ZX2+Fex5zu8LhRQoMeMPEHbc73UKZ0FQ54YrQtUxE1VVhMwzeNtKRPAu5aXks4FasbMe4xB4bWrmq6Jlxw==",
       "license": "MIT",
       "dependencies": {
         "langium": "^4.0.0"
@@ -21826,9 +21838,9 @@
       }
     },
     "node_modules/@xmldom/xmldom": {
-      "version": "0.8.10",
-      "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.8.10.tgz",
-      "integrity": "sha512-2WALfTl4xo2SkGCYRt6rDTFfk9R1czmBvUQy12gK2KuRKIpWEhcbbzy8EZXtz/jkRqHX8bFEc6FC1HjX4TUWYw==",
+      "version": "0.8.12",
+      "resolved": "https://registry.npmjs.org/@xmldom/xmldom/-/xmldom-0.8.12.tgz",
+      "integrity": "sha512-9k/gHF6n/pAi/9tqr3m3aqkuiNosYTurLLUtc7xQ9sxB/wm7WPygCv8GYa6mS0fLJEHhqMC1ATYhz++U/lRHqg==",
       "license": "MIT",
       "engines": {
         "node": ">=10.0.0"
@@ -22506,13 +22518,6 @@
         "node": ">= 0.4"
       }
     },
-    "node_modules/b4a": {
-      "version": "1.6.7",
-      "resolved": "https://registry.npmjs.org/b4a/-/b4a-1.6.7.tgz",
-      "integrity": "sha512-OnAYlL5b7LEkALw87fUVafQw5rVR9RjwGd4KUwNQ6DrrNmaVaUCgLipfVlzrPQ4tWOR9P0IXGNOx50jYCCdSJg==",
-      "dev": true,
-      "license": "Apache-2.0"
-    },
     "node_modules/babel-jest": {
       "version": "30.2.0",
       "resolved": "https://registry.npmjs.org/babel-jest/-/babel-jest-30.2.0.tgz",
@@ -22726,12 +22731,101 @@
       "integrity": "sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw=="
     },
     "node_modules/bare-events": {
-      "version": "2.6.0",
-      "resolved": "https://registry.npmjs.org/bare-events/-/bare-events-2.6.0.tgz",
-      "integrity": "sha512-EKZ5BTXYExaNqi3I3f9RtEsaI/xBSGjE0XZCZilPzFAV/goswFHuPd9jEZlPIZ/iNZJwDSao9qRiScySz7MbQg==",
+      "version": "2.8.2",
+      "resolved": "https://registry.npmjs.org/bare-events/-/bare-events-2.8.2.tgz",
+      "integrity": "sha512-riJjyv1/mHLIPX4RwiK+oW9/4c3TEUeORHKefKAKnZ5kyslbN+HXowtbaVEqt4IMUB7OXlfixcs6gsFeo/jhiQ==",
       "dev": true,
       "license": "Apache-2.0",
-      "optional": true
+      "peerDependencies": {
+        "bare-abort-controller": "*"
+      },
+      "peerDependenciesMeta": {
+        "bare-abort-controller": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/bare-fs": {
+      "version": "4.6.0",
+      "resolved": "https://registry.npmjs.org/bare-fs/-/bare-fs-4.6.0.tgz",
+      "integrity": "sha512-2YkS7NuiJceSEbyEOdSNLE9tsGd+f4+f7C+Nik/MCk27SYdwIMPT/yRKvg++FZhQXgk0KWJKJyXX9RhVV0RGqA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "bare-events": "^2.5.4",
+        "bare-path": "^3.0.0",
+        "bare-stream": "^2.6.4",
+        "bare-url": "^2.2.2",
+        "fast-fifo": "^1.3.2"
+      },
+      "engines": {
+        "bare": ">=1.16.0"
+      },
+      "peerDependencies": {
+        "bare-buffer": "*"
+      },
+      "peerDependenciesMeta": {
+        "bare-buffer": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/bare-os": {
+      "version": "3.8.7",
+      "resolved": "https://registry.npmjs.org/bare-os/-/bare-os-3.8.7.tgz",
+      "integrity": "sha512-G4Gr1UsGeEy2qtDTZwL7JFLo2wapUarz7iTMcYcMFdS89AIQuBoyjgXZz0Utv7uHs3xA9LckhVbeBi8lEQrC+w==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
+        "bare": ">=1.14.0"
+      }
+    },
+    "node_modules/bare-path": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/bare-path/-/bare-path-3.0.0.tgz",
+      "integrity": "sha512-tyfW2cQcB5NN8Saijrhqn0Zh7AnFNsnczRcuWODH0eYAXBsJ5gVxAUuNr7tsHSC6IZ77cA0SitzT+s47kot8Mw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "bare-os": "^3.0.1"
+      }
+    },
+    "node_modules/bare-stream": {
+      "version": "2.12.0",
+      "resolved": "https://registry.npmjs.org/bare-stream/-/bare-stream-2.12.0.tgz",
+      "integrity": "sha512-w28i8lkBgREV3rPXGbgK+BO66q+ZpKqRWrZLiCdmmUlLPrQ45CzkvRhN+7lnv00Gpi2zy5naRxnUFAxCECDm9g==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "streamx": "^2.25.0",
+        "teex": "^1.0.1"
+      },
+      "peerDependencies": {
+        "bare-abort-controller": "*",
+        "bare-buffer": "*",
+        "bare-events": "*"
+      },
+      "peerDependenciesMeta": {
+        "bare-abort-controller": {
+          "optional": true
+        },
+        "bare-buffer": {
+          "optional": true
+        },
+        "bare-events": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/bare-url": {
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/bare-url/-/bare-url-2.4.0.tgz",
+      "integrity": "sha512-NSTU5WN+fy/L0DDenfE8SXQna4voXuW0FHM7wH8i3/q9khUSchfPbPezO4zSFMnDGIf9YE+mt/RWhZgNRKRIXA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "bare-path": "^3.0.0"
+      }
     },
     "node_modules/base64-js": {
       "version": "1.5.1",
@@ -23455,6 +23549,12 @@
         "chevrotain": "^11.0.0"
       }
     },
+    "node_modules/chevrotain/node_modules/lodash-es": {
+      "version": "4.17.23",
+      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.17.23.tgz",
+      "integrity": "sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==",
+      "license": "MIT"
+    },
     "node_modules/chokidar": {
       "version": "3.5.3",
       "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.5.3.tgz",
@@ -26711,6 +26811,16 @@
         "node": ">=0.8.x"
       }
     },
+    "node_modules/events-universal": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/events-universal/-/events-universal-1.0.1.tgz",
+      "integrity": "sha512-LUd5euvbMLpwOF8m6ivPCbhQeSiYVNb8Vs0fQ8QjXo0JTkEHpz8pxdQf0gStltaPpw0Cca8b39KxvK9cfKRiAw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "bare-events": "^2.7.0"
+      }
+    },
     "node_modules/eventsource": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/eventsource/-/eventsource-3.0.2.tgz",
@@ -32016,15 +32126,15 @@
       }
     },
     "node_modules/lodash": {
-      "version": "4.17.23",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.23.tgz",
-      "integrity": "sha512-LgVTMpQtIopCi79SJeDiP0TfWi5CNEc/L/aRdTh3yIvmZXTnheWpKjSZhnvMl8iXbC1tFg9gdHHDMLoV7CnG+w==",
+      "version": "4.18.1",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.18.1.tgz",
+      "integrity": "sha512-dMInicTPVE8d1e5otfwmmjlxkZoUpiVLwyeTdUsi/Caj/gfzzblBcCE5sRHV/AsjuCmxWrte2TNGSYuCeCq+0Q==",
       "license": "MIT"
     },
     "node_modules/lodash-es": {
-      "version": "4.17.23",
-      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.17.23.tgz",
-      "integrity": "sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==",
+      "version": "4.18.1",
+      "resolved": "https://registry.npmjs.org/lodash-es/-/lodash-es-4.18.1.tgz",
+      "integrity": "sha512-J8xewKD/Gk22OZbhpOVSwcs60zhd95ESDwezOFuA3/099925PdHJ7OFHNTGtajL3AlZkykD32HykiMo+BIBI8A==",
       "license": "MIT"
     },
     "node_modules/lodash.camelcase": {
@@ -33243,14 +33353,14 @@
       }
     },
     "node_modules/mermaid": {
-      "version": "11.13.0",
-      "resolved": "https://registry.npmjs.org/mermaid/-/mermaid-11.13.0.tgz",
-      "integrity": "sha512-fEnci+Immw6lKMFI8sqzjlATTyjLkRa6axrEgLV2yHTfv8r+h1wjFbV6xeRtd4rUV1cS4EpR9rwp3Rci7TRWDw==",
+      "version": "11.14.0",
+      "resolved": "https://registry.npmjs.org/mermaid/-/mermaid-11.14.0.tgz",
+      "integrity": "sha512-GSGloRsBs+JINmmhl0JDwjpuezCsHB4WGI4NASHxL3fHo3o/BRXTxhDLKnln8/Q0lRFRyDdEjmk1/d5Sn1Xz8g==",
       "license": "MIT",
       "dependencies": {
         "@braintree/sanitize-url": "^7.1.1",
         "@iconify/utils": "^3.0.2",
-        "@mermaid-js/parser": "^1.0.1",
+        "@mermaid-js/parser": "^1.1.0",
         "@types/d3": "^7.4.3",
         "@upsetjs/venn.js": "^2.0.0",
         "cytoscape": "^3.33.1",
@@ -34129,42 +34239,123 @@
       }
     },
     "node_modules/mongodb-memory-server": {
-      "version": "10.1.4",
-      "resolved": "https://registry.npmjs.org/mongodb-memory-server/-/mongodb-memory-server-10.1.4.tgz",
-      "integrity": "sha512-+oKQ/kc3CX+816oPFRtaF0CN4vNcGKNjpOQe4bHo/21A3pMD+lC7Xz1EX5HP7siCX4iCpVchDMmCOFXVQSGkUg==",
+      "version": "11.0.1",
+      "resolved": "https://registry.npmjs.org/mongodb-memory-server/-/mongodb-memory-server-11.0.1.tgz",
+      "integrity": "sha512-nUlKovSJZBh7q5hPsewFRam9H66D08Ne18nyknkNalfXMPtK1Og3kOcuqQhcX88x/pghSZPIJHrLbxNFW3OWiw==",
       "dev": true,
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
-        "mongodb-memory-server-core": "10.1.4",
-        "tslib": "^2.7.0"
+        "mongodb-memory-server-core": "11.0.1",
+        "tslib": "^2.8.1"
       },
       "engines": {
-        "node": ">=16.20.1"
+        "node": ">=20.19.0"
       }
     },
     "node_modules/mongodb-memory-server-core": {
-      "version": "10.1.4",
-      "resolved": "https://registry.npmjs.org/mongodb-memory-server-core/-/mongodb-memory-server-core-10.1.4.tgz",
-      "integrity": "sha512-o8fgY7ZalEd8pGps43fFPr/hkQu1L8i6HFEGbsTfA2zDOW0TopgpswaBCqDr0qD7ptibyPfB5DmC+UlIxbThzA==",
+      "version": "11.0.1",
+      "resolved": "https://registry.npmjs.org/mongodb-memory-server-core/-/mongodb-memory-server-core-11.0.1.tgz",
+      "integrity": "sha512-IcIb2S9Xf7Lmz43Z1ZujMqNg7PU5Q7yn+4wOnu7l6pfeGPkEmlqzV1hIbroVx8s4vXhPB1oMGC1u8clW7aj3Xw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "async-mutex": "^0.5.0",
         "camelcase": "^6.3.0",
-        "debug": "^4.3.7",
+        "debug": "^4.4.3",
         "find-cache-dir": "^3.3.2",
-        "follow-redirects": "^1.15.9",
-        "https-proxy-agent": "^7.0.5",
-        "mongodb": "^6.9.0",
+        "follow-redirects": "^1.15.11",
+        "https-proxy-agent": "^7.0.6",
+        "mongodb": "^7.0.0",
         "new-find-package-json": "^2.0.0",
-        "semver": "^7.6.3",
+        "semver": "^7.7.3",
         "tar-stream": "^3.1.7",
-        "tslib": "^2.7.0",
-        "yauzl": "^3.1.3"
+        "tslib": "^2.8.1",
+        "yauzl": "^3.2.0"
       },
       "engines": {
-        "node": ">=16.20.1"
+        "node": ">=20.19.0"
+      }
+    },
+    "node_modules/mongodb-memory-server-core/node_modules/@types/whatwg-url": {
+      "version": "13.0.0",
+      "resolved": "https://registry.npmjs.org/@types/whatwg-url/-/whatwg-url-13.0.0.tgz",
+      "integrity": "sha512-N8WXpbE6Wgri7KUSvrmQcqrMllKZ9uxkYWMt+mCSGwNc0Hsw9VQTW7ApqI4XNrx6/SaM2QQJCzMPDEXE058s+Q==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/webidl-conversions": "*"
+      }
+    },
+    "node_modules/mongodb-memory-server-core/node_modules/bson": {
+      "version": "7.2.0",
+      "resolved": "https://registry.npmjs.org/bson/-/bson-7.2.0.tgz",
+      "integrity": "sha512-YCEo7KjMlbNlyHhz7zAZNDpIpQbd+wOEHJYezv0nMYTn4x31eIUM2yomNNubclAt63dObUzKHWsBLJ9QcZNSnQ==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=20.19.0"
+      }
+    },
+    "node_modules/mongodb-memory-server-core/node_modules/mongodb": {
+      "version": "7.1.1",
+      "resolved": "https://registry.npmjs.org/mongodb/-/mongodb-7.1.1.tgz",
+      "integrity": "sha512-067DXiMjcpYQl6bGjWQoTUEE9UoRViTtKFcoqX7z08I+iDZv/emH1g8XEFiO3qiDfXAheT5ozl1VffDTKhIW/w==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@mongodb-js/saslprep": "^1.3.0",
+        "bson": "^7.1.1",
+        "mongodb-connection-string-url": "^7.0.0"
+      },
+      "engines": {
+        "node": ">=20.19.0"
+      },
+      "peerDependencies": {
+        "@aws-sdk/credential-providers": "^3.806.0",
+        "@mongodb-js/zstd": "^7.0.0",
+        "gcp-metadata": "^7.0.1",
+        "kerberos": "^7.0.0",
+        "mongodb-client-encryption": ">=7.0.0 <7.1.0",
+        "snappy": "^7.3.2",
+        "socks": "^2.8.6"
+      },
+      "peerDependenciesMeta": {
+        "@aws-sdk/credential-providers": {
+          "optional": true
+        },
+        "@mongodb-js/zstd": {
+          "optional": true
+        },
+        "gcp-metadata": {
+          "optional": true
+        },
+        "kerberos": {
+          "optional": true
+        },
+        "mongodb-client-encryption": {
+          "optional": true
+        },
+        "snappy": {
+          "optional": true
+        },
+        "socks": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/mongodb-memory-server-core/node_modules/mongodb-connection-string-url": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmjs.org/mongodb-connection-string-url/-/mongodb-connection-string-url-7.0.1.tgz",
+      "integrity": "sha512-h0AZ9A7IDVwwHyMxmdMXKy+9oNlF0zFoahHiX3vQ8e3KFcSP3VmsmfvtRSuLPxmyv2vjIDxqty8smTgie/SNRQ==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@types/whatwg-url": "^13.0.0",
+        "whatwg-url": "^14.1.0"
+      },
+      "engines": {
+        "node": ">=20.19.0"
       }
     },
     "node_modules/mongoose": {
@@ -40366,17 +40557,15 @@
       }
     },
     "node_modules/streamx": {
-      "version": "2.22.1",
-      "resolved": "https://registry.npmjs.org/streamx/-/streamx-2.22.1.tgz",
-      "integrity": "sha512-znKXEBxfatz2GBNK02kRnCXjV+AA4kjZIUxeWSr3UGirZMJfTE9uiwKHobnbgxWyL/JWro8tTq+vOqAK1/qbSA==",
+      "version": "2.25.0",
+      "resolved": "https://registry.npmjs.org/streamx/-/streamx-2.25.0.tgz",
+      "integrity": "sha512-0nQuG6jf1w+wddNEEXCF4nTg3LtufWINB5eFEN+5TNZW7KWJp6x87+JFL43vaAUPyCfH1wID+mNVyW6OHtFamg==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
+        "events-universal": "^1.0.0",
         "fast-fifo": "^1.3.2",
         "text-decoder": "^1.1.0"
-      },
-      "optionalDependencies": {
-        "bare-events": "^2.2.0"
       }
     },
     "node_modules/strict-event-emitter": {
@@ -41142,17 +41331,43 @@
       "license": "MIT"
     },
     "node_modules/tar-stream": {
-      "version": "3.1.7",
-      "resolved": "https://registry.npmjs.org/tar-stream/-/tar-stream-3.1.7.tgz",
-      "integrity": "sha512-qJj60CXt7IU1Ffyc3NJMjh6EkuCFej46zUqJ4J7pqYlThyd9bO0XBTmcOIhSzZJVWfsLks0+nle/j538YAW9RQ==",
+      "version": "3.1.8",
+      "resolved": "https://registry.npmjs.org/tar-stream/-/tar-stream-3.1.8.tgz",
+      "integrity": "sha512-U6QpVRyCGHva435KoNWy9PRoi2IFYCgtEhq9nmrPPpbRacPs9IH4aJ3gbrFC8dPcXvdSZ4XXfXT5Fshbp2MtlQ==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "b4a": "^1.6.4",
+        "bare-fs": "^4.5.5",
         "fast-fifo": "^1.2.0",
         "streamx": "^2.15.0"
       }
     },
+    "node_modules/tar-stream/node_modules/b4a": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/b4a/-/b4a-1.8.0.tgz",
+      "integrity": "sha512-qRuSmNSkGQaHwNbM7J78Wwy+ghLEYF1zNrSeMxj4Kgw6y33O3mXcQ6Ie9fRvfU/YnxWkOchPXbaLb73TkIsfdg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "peerDependencies": {
+        "react-native-b4a": "*"
+      },
+      "peerDependenciesMeta": {
+        "react-native-b4a": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/teex": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/teex/-/teex-1.0.1.tgz",
+      "integrity": "sha512-eYE6iEI62Ni1H8oIa7KlDU6uQBtqr4Eajni3wX7rpfXD8ysFx8z0+dri+KWEPWpBsxXfxu58x/0jvTVT1ekOSg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "streamx": "^2.12.5"
+      }
+    },
     "node_modules/temp-dir": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/temp-dir/-/temp-dir-2.0.0.tgz",
@@ -41254,15 +41469,30 @@
       }
     },
     "node_modules/text-decoder": {
-      "version": "1.2.3",
-      "resolved": "https://registry.npmjs.org/text-decoder/-/text-decoder-1.2.3.tgz",
-      "integrity": "sha512-3/o9z3X0X0fTupwsYvR03pJ/DjWuqqrfwBgTQzdWDiQSm9KitAyz/9WqsT2JQW7KV2m+bC2ol/zqpW37NHxLaA==",
+      "version": "1.2.7",
+      "resolved": "https://registry.npmjs.org/text-decoder/-/text-decoder-1.2.7.tgz",
+      "integrity": "sha512-vlLytXkeP4xvEq2otHeJfSQIRyWxo/oZGEbXrtEEF9Hnmrdly59sUbzZ/QgyWuLYHctCHxFF4tRQZNQ9k60ExQ==",
       "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
         "b4a": "^1.6.4"
       }
     },
+    "node_modules/text-decoder/node_modules/b4a": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/b4a/-/b4a-1.8.0.tgz",
+      "integrity": "sha512-qRuSmNSkGQaHwNbM7J78Wwy+ghLEYF1zNrSeMxj4Kgw6y33O3mXcQ6Ie9fRvfU/YnxWkOchPXbaLb73TkIsfdg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "peerDependencies": {
+        "react-native-b4a": "*"
+      },
+      "peerDependenciesMeta": {
+        "react-native-b4a": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/text-hex": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/text-hex/-/text-hex-1.0.0.tgz",
@@ -45892,7 +46122,7 @@
     },
     "packages/data-provider": {
       "name": "librechat-data-provider",
-      "version": "0.8.406",
+      "version": "0.8.407",
       "license": "ISC",
       "dependencies": {
         "axios": "1.13.6",
@@ -45988,7 +46218,7 @@
         "@types/node": "^20.3.0",
         "jest": "^30.2.0",
         "jest-junit": "^16.0.0",
-        "mongodb-memory-server": "^10.1.4",
+        "mongodb-memory-server": "^11.0.1",
         "rimraf": "^6.1.3",
         "rollup": "^4.34.9",
         "rollup-plugin-peer-deps-external": "^2.2.4",
diff --git a/packages/api/src/admin/config.handler.spec.ts b/packages/api/src/admin/config.handler.spec.ts
index ad33f5f158..8f4e2002a5 100644
--- a/packages/api/src/admin/config.handler.spec.ts
+++ b/packages/api/src/admin/config.handler.spec.ts
@@ -54,7 +54,7 @@ function createHandlers(overrides = {}) {
     toggleConfigActive: jest.fn().mockResolvedValue({ _id: 'c1', isActive: false }),
     hasConfigCapability: jest.fn().mockResolvedValue(true),
 
-    getAppConfig: jest.fn().mockResolvedValue({ interface: { endpointsMenu: true } }),
+    getAppConfig: jest.fn().mockResolvedValue({ interface: { modelSelect: true } }),
     ...overrides,
   };
   const handlers = createAdminConfigHandlers(deps);
@@ -133,7 +133,7 @@ describe('createAdminConfigHandlers', () => {
       });
       const req = mockReq({
         params: { principalType: 'role', principalId: 'admin' },
-        body: { overrides: { interface: { endpointsMenu: false } } },
+        body: { overrides: { interface: { modelSelect: false } } },
       });
       const res = mockRes();
 
@@ -148,7 +148,7 @@ describe('createAdminConfigHandlers', () => {
       });
       const req = mockReq({
         params: { principalType: 'role', principalId: 'admin' },
-        body: { overrides: { interface: { endpointsMenu: false } } },
+        body: { overrides: { interface: { modelSelect: false } } },
       });
       const res = mockRes();
 
@@ -178,7 +178,7 @@ describe('createAdminConfigHandlers', () => {
         params: { principalType: 'role', principalId: 'admin' },
         body: {
           overrides: {
-            interface: { endpointsMenu: false, prompts: false, agents: { use: false } },
+            interface: { modelSelect: false, prompts: false, agents: { use: false } },
           },
         },
       });
@@ -188,7 +188,7 @@ describe('createAdminConfigHandlers', () => {
 
       expect(res.statusCode).toBe(201);
       const savedOverrides = deps.upsertConfig.mock.calls[0][3];
-      expect(savedOverrides.interface).toEqual({ endpointsMenu: false });
+      expect(savedOverrides.interface).toEqual({ modelSelect: false });
     });
 
     it('preserves UI sub-keys in composite permission fields like mcpServers', async () => {
@@ -263,17 +263,13 @@ describe('createAdminConfigHandlers', () => {
       const { handlers, deps } = createHandlers();
       const req = mockReq({
         params: { principalType: 'role', principalId: 'admin' },
-        query: { fieldPath: 'interface.endpointsMenu' },
+        query: { fieldPath: 'interface.modelSelect' },
       });
       const res = mockRes();
 
       await handlers.deleteConfigField(req, res);
 
-      expect(deps.unsetConfigField).toHaveBeenCalledWith(
-        'role',
-        'admin',
-        'interface.endpointsMenu',
-      );
+      expect(deps.unsetConfigField).toHaveBeenCalledWith('role', 'admin', 'interface.modelSelect');
     });
 
     it('allows deleting mcpServers UI sub-key paths', async () => {
@@ -343,18 +339,14 @@ describe('createAdminConfigHandlers', () => {
       const { handlers, deps } = createHandlers();
       const req = mockReq({
         params: { principalType: 'role', principalId: 'admin' },
-        query: { fieldPath: 'interface.endpointsMenu' },
+        query: { fieldPath: 'interface.modelSelect' },
       });
       const res = mockRes();
 
       await handlers.deleteConfigField(req, res);
 
       expect(res.statusCode).toBe(200);
-      expect(deps.unsetConfigField).toHaveBeenCalledWith(
-        'role',
-        'admin',
-        'interface.endpointsMenu',
-      );
+      expect(deps.unsetConfigField).toHaveBeenCalledWith('role', 'admin', 'interface.modelSelect');
     });
 
     it('returns 400 when fieldPath query param is missing', async () => {
@@ -407,7 +399,7 @@ describe('createAdminConfigHandlers', () => {
         params: { principalType: 'role', principalId: 'admin' },
         body: {
           entries: [
-            { fieldPath: 'interface.endpointsMenu', value: false },
+            { fieldPath: 'interface.modelSelect', value: false },
             { fieldPath: 'interface.prompts', value: false },
           ],
         },
@@ -418,7 +410,7 @@ describe('createAdminConfigHandlers', () => {
 
       expect(res.statusCode).toBe(200);
       const patchedFields = deps.patchConfigFields.mock.calls[0][3];
-      expect(patchedFields['interface.endpointsMenu']).toBe(false);
+      expect(patchedFields['interface.modelSelect']).toBe(false);
       expect(patchedFields['interface.prompts']).toBeUndefined();
     });
 
@@ -632,21 +624,21 @@ describe('createAdminConfigHandlers', () => {
       name: 'upsertConfigOverrides',
       reqOverrides: {
         params: { principalType: 'role', principalId: 'admin' },
-        body: { overrides: { interface: { endpointsMenu: false } } },
+        body: { overrides: { interface: { modelSelect: false } } },
       },
     },
     {
       name: 'patchConfigField',
       reqOverrides: {
         params: { principalType: 'role', principalId: 'admin' },
-        body: { entries: [{ fieldPath: 'interface.endpointsMenu', value: false }] },
+        body: { entries: [{ fieldPath: 'interface.modelSelect', value: false }] },
       },
     },
     {
       name: 'deleteConfigField',
       reqOverrides: {
         params: { principalType: 'role', principalId: 'admin' },
-        query: { fieldPath: 'interface.endpointsMenu' },
+        query: { fieldPath: 'interface.modelSelect' },
       },
     },
     {
@@ -775,7 +767,7 @@ describe('createAdminConfigHandlers', () => {
       await handlers.getBaseConfig(req, res);
 
       expect(res.statusCode).toBe(200);
-      expect(res.body!.config).toEqual({ interface: { endpointsMenu: true } });
+      expect(res.body!.config).toEqual({ interface: { modelSelect: true } });
     });
   });
 });
diff --git a/packages/api/src/admin/config.spec.ts b/packages/api/src/admin/config.spec.ts
index 499cfaa35b..3298cb5faa 100644
--- a/packages/api/src/admin/config.spec.ts
+++ b/packages/api/src/admin/config.spec.ts
@@ -2,7 +2,7 @@ import { isValidFieldPath, getTopLevelSection } from './config';
 
 describe('isValidFieldPath', () => {
   it('accepts simple dot paths', () => {
-    expect(isValidFieldPath('interface.endpointsMenu')).toBe(true);
+    expect(isValidFieldPath('interface.modelSelect')).toBe(true);
     expect(isValidFieldPath('registration.socialLogins')).toBe(true);
     expect(isValidFieldPath('a')).toBe(true);
     expect(isValidFieldPath('a.b.c.d')).toBe(true);
@@ -47,7 +47,7 @@ describe('isValidFieldPath', () => {
 
 describe('getTopLevelSection', () => {
   it('returns first segment of a dot path', () => {
-    expect(getTopLevelSection('interface.endpointsMenu')).toBe('interface');
+    expect(getTopLevelSection('interface.modelSelect')).toBe('interface');
     expect(getTopLevelSection('registration.socialLogins.github')).toBe('registration');
   });
 
diff --git a/packages/api/src/admin/config.ts b/packages/api/src/admin/config.ts
index 357096da9b..c1ce2cb13f 100644
--- a/packages/api/src/admin/config.ts
+++ b/packages/api/src/admin/config.ts
@@ -40,7 +40,7 @@ export function getTopLevelSection(fieldPath: string): string {
  * - `"interface.mcpServers.use"` → true (permission sub-key)
  * - `"interface.mcpServers.placeholder"` → false (UI-only sub-key)
  * - `"interface.peoplePicker.users"` → true (all peoplePicker sub-keys are permissions)
- * - `"interface.endpointsMenu"` → false (UI-only field)
+ * - `"interface.modelSelect"` → false (UI-only field)
  */
 function isInterfacePermissionPath(fieldPath: string): boolean {
   const parts = fieldPath.split('.');
diff --git a/packages/api/src/app/AppService.spec.ts b/packages/api/src/app/AppService.spec.ts
index df607d612b..2c07460b84 100644
--- a/packages/api/src/app/AppService.spec.ts
+++ b/packages/api/src/app/AppService.spec.ts
@@ -85,7 +85,7 @@ describe('AppService', () => {
   it('should correctly assign process.env and initialize app config based on custom config', async () => {
     const config: Partial<TCustomConfig> = {
       registration: { socialLogins: ['testLogin'] },
-      fileStrategy: 'testStrategy' as FileSources,
+      fileStrategy: FileSources.s3,
       balance: {
         enabled: true,
       },
@@ -93,22 +93,20 @@ describe('AppService', () => {
 
     const result = await AppService({ config, systemTools: mockSystemTools });
 
-    expect(process.env.CDN_PROVIDER).toEqual('testStrategy');
+    expect(process.env.CDN_PROVIDER).toEqual('s3');
 
     expect(result).toEqual(
       expect.objectContaining({
         config: expect.objectContaining({
-          fileStrategy: 'testStrategy',
+          fileStrategy: 's3',
         }),
         registration: expect.objectContaining({
           socialLogins: ['testLogin'],
         }),
-        fileStrategy: 'testStrategy',
+        fileStrategy: 's3',
         interfaceConfig: expect.objectContaining({
-          endpointsMenu: true,
           modelSelect: true,
           parameters: true,
-          sidePanel: true,
           presets: true,
         }),
         mcpConfig: null,
diff --git a/packages/api/src/app/checks.ts b/packages/api/src/app/checks.ts
index 66f5b620e6..50312267ac 100644
--- a/packages/api/src/app/checks.ts
+++ b/packages/api/src/app/checks.ts
@@ -192,16 +192,13 @@ export function checkInterfaceConfig(appConfig: AppConfig) {
     if (i === 0) i++;
   }
 
-  // warn about config.modelSpecs.enforce if true and if any of these, endpointsMenu, modelSelect, presets, or parameters are enabled, that enforcing model specs can conflict with these options.
+  // warn about config.modelSpecs.enforce if true and if any of these, modelSelect, presets, or parameters are enabled, that enforcing model specs can conflict with these options.
   if (
     appConfig?.modelSpecs?.enforce &&
-    (interfaceConfig?.endpointsMenu ||
-      interfaceConfig?.modelSelect ||
-      interfaceConfig?.presets ||
-      interfaceConfig?.parameters)
+    (interfaceConfig?.modelSelect || interfaceConfig?.presets || interfaceConfig?.parameters)
   ) {
     logger.warn(
-      "Note: Enforcing model specs can conflict with the interface options: endpointsMenu, modelSelect, presets, and parameters. It's recommended to disable these options from the interface or disable enforcing model specs.",
+      "Note: Enforcing model specs can conflict with the interface options: modelSelect, presets, and parameters. It's recommended to disable these options from the interface or disable enforcing model specs.",
     );
     if (i === 0) i++;
   }
diff --git a/packages/api/src/app/config.test.ts b/packages/api/src/app/config.test.ts
index 3e2ee6d143..a3e7401efd 100644
--- a/packages/api/src/app/config.test.ts
+++ b/packages/api/src/app/config.test.ts
@@ -10,7 +10,7 @@ const createTestAppConfig = (overrides: Partial<AppConfig> = {}): AppConfig => {
     version: '1.0.0',
     cache: true,
     interface: {
-      endpointsMenu: true,
+      modelSelect: true,
     },
     registration: {
       socialLogins: [],
diff --git a/packages/api/src/app/service.spec.ts b/packages/api/src/app/service.spec.ts
index 8d168095c7..e5e076c8eb 100644
--- a/packages/api/src/app/service.spec.ts
+++ b/packages/api/src/app/service.spec.ts
@@ -34,7 +34,7 @@ function createMockCache(namespace = 'app_config') {
 
 function createDeps(overrides = {}) {
   const cache = createMockCache();
-  const baseConfig = { interfaceConfig: { endpointsMenu: true }, endpoints: ['openAI'] };
+  const baseConfig = { interfaceConfig: { modelSelect: true }, endpoints: ['openAI'] };
 
   return {
     loadBaseConfig: jest.fn().mockResolvedValue(baseConfig),
@@ -79,7 +79,7 @@ describe('createAppConfigService', () => {
         getApplicableConfigs: jest
           .fn()
           .mockResolvedValue([
-            { priority: 10, overrides: { interface: { endpointsMenu: false } }, isActive: true },
+            { priority: 10, overrides: { interface: { modelSelect: false } }, isActive: true },
           ]),
       });
       const { getAppConfig } = createAppConfigService(deps);
@@ -125,7 +125,7 @@ describe('createAppConfigService', () => {
         getApplicableConfigs: jest
           .fn()
           .mockResolvedValue([
-            { priority: 10, overrides: { interface: { endpointsMenu: false } }, isActive: true },
+            { priority: 10, overrides: { interface: { modelSelect: false } }, isActive: true },
           ]),
       });
       const { getAppConfig } = createAppConfigService(deps);
@@ -133,7 +133,7 @@ describe('createAppConfigService', () => {
       const config = await getAppConfig({ role: 'ADMIN' });
 
       const merged = config as TestConfig;
-      expect(merged.interfaceConfig?.endpointsMenu).toBe(false);
+      expect(merged.interfaceConfig?.modelSelect).toBe(false);
       expect(merged.endpoints).toEqual(['openAI']);
     });
 
diff --git a/packages/api/src/auth/adminPkce.spec.ts b/packages/api/src/auth/adminPkce.spec.ts
new file mode 100644
index 0000000000..906b7d400b
--- /dev/null
+++ b/packages/api/src/auth/adminPkce.spec.ts
@@ -0,0 +1,211 @@
+import { Keyv } from 'keyv';
+
+jest.mock(
+  '@librechat/data-schemas',
+  () => ({
+    logger: {
+      info: jest.fn(),
+      warn: jest.fn(),
+      error: jest.fn(),
+    },
+  }),
+  { virtual: true },
+);
+
+import { stripCodeChallenge, storeAndStripChallenge } from './exchange';
+import type { PkceStrippableRequest } from './exchange';
+
+function makeReq(overrides: Partial<PkceStrippableRequest> = {}): PkceStrippableRequest {
+  return { query: {}, originalUrl: '', url: '', ...overrides };
+}
+
+describe('stripCodeChallenge', () => {
+  const challenge = 'a'.repeat(64);
+
+  it('removes code_challenge from req.query and both URL strings (sole param)', () => {
+    const req = makeReq({
+      query: { code_challenge: challenge },
+      originalUrl: `/api/admin/oauth/openid?code_challenge=${challenge}`,
+      url: `/oauth/openid?code_challenge=${challenge}`,
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/api/admin/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+
+  it('preserves other params when code_challenge is last', () => {
+    const req = makeReq({
+      query: { foo: 'bar', code_challenge: challenge },
+      originalUrl: `/oauth/openid?foo=bar&code_challenge=${challenge}`,
+      url: `/oauth/openid?foo=bar&code_challenge=${challenge}`,
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.query.foo).toBe('bar');
+    expect(req.originalUrl).toBe('/oauth/openid?foo=bar');
+    expect(req.url).toBe('/oauth/openid?foo=bar');
+  });
+
+  it('preserves other params when code_challenge is first of multiple', () => {
+    const req = makeReq({
+      query: { code_challenge: challenge, foo: 'bar' },
+      originalUrl: `/oauth/openid?code_challenge=${challenge}&foo=bar`,
+      url: `/oauth/openid?code_challenge=${challenge}&foo=bar`,
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/oauth/openid?foo=bar');
+    expect(req.url).toBe('/oauth/openid?foo=bar');
+  });
+
+  it('preserves other params when code_challenge is in the middle', () => {
+    const req = makeReq({
+      query: { a: '1', code_challenge: challenge, b: '2' },
+      originalUrl: `/oauth/openid?a=1&code_challenge=${challenge}&b=2`,
+      url: `/oauth/openid?a=1&code_challenge=${challenge}&b=2`,
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/oauth/openid?a=1&b=2');
+    expect(req.url).toBe('/oauth/openid?a=1&b=2');
+  });
+
+  it('handles empty code_challenge= value', () => {
+    const req = makeReq({
+      query: { code_challenge: '' },
+      originalUrl: '/oauth/openid?code_challenge=',
+      url: '/oauth/openid?code_challenge=',
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+
+  it('is a no-op when no code_challenge is present', () => {
+    const req = makeReq({
+      query: { foo: 'bar' },
+      originalUrl: '/oauth/openid?foo=bar',
+      url: '/oauth/openid?foo=bar',
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.query.foo).toBe('bar');
+    expect(req.originalUrl).toBe('/oauth/openid?foo=bar');
+    expect(req.url).toBe('/oauth/openid?foo=bar');
+  });
+
+  it('is a no-op on a bare path with no query string', () => {
+    const req = makeReq({
+      query: {},
+      originalUrl: '/oauth/openid',
+      url: '/oauth/openid',
+    });
+
+    stripCodeChallenge(req);
+
+    expect(req.originalUrl).toBe('/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+});
+
+describe('storeAndStripChallenge', () => {
+  const challenge = 'a'.repeat(64);
+
+  it('stores valid challenge in cache and strips from request', async () => {
+    const cache = new Keyv();
+    const setSpy = jest.spyOn(cache, 'set');
+    const req = makeReq({
+      query: { code_challenge: challenge },
+      originalUrl: `/oauth/openid?code_challenge=${challenge}`,
+      url: `/oauth/openid?code_challenge=${challenge}`,
+    });
+
+    const result = await storeAndStripChallenge(cache, req, 'test-state', 'openid');
+
+    expect(result).toBe(true);
+    expect(setSpy).toHaveBeenCalledWith(`pkce:test-state`, challenge, expect.any(Number));
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+
+  it('strips and returns true when no code_challenge is present', async () => {
+    const cache = new Keyv();
+    const setSpy = jest.spyOn(cache, 'set');
+    const req = makeReq({
+      query: {},
+      originalUrl: '/oauth/openid',
+      url: '/oauth/openid',
+    });
+
+    const result = await storeAndStripChallenge(cache, req, 'test-state', 'openid');
+
+    expect(result).toBe(true);
+    expect(setSpy).not.toHaveBeenCalled();
+    expect(req.originalUrl).toBe('/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+
+  it('strips and returns true when code_challenge is invalid (not 64 hex)', async () => {
+    const cache = new Keyv();
+    const setSpy = jest.spyOn(cache, 'set');
+    const req = makeReq({
+      query: { code_challenge: 'too-short' },
+      originalUrl: '/oauth/openid?code_challenge=too-short',
+      url: '/oauth/openid?code_challenge=too-short',
+    });
+
+    const result = await storeAndStripChallenge(cache, req, 'test-state', 'openid');
+
+    expect(result).toBe(true);
+    expect(setSpy).not.toHaveBeenCalled();
+    expect(req.query.code_challenge).toBeUndefined();
+    expect(req.originalUrl).toBe('/oauth/openid');
+    expect(req.url).toBe('/oauth/openid');
+  });
+
+  it('returns false and does not strip on cache failure', async () => {
+    const cache = new Keyv();
+    jest.spyOn(cache, 'set').mockRejectedValueOnce(new Error('cache down'));
+    const req = makeReq({
+      query: { code_challenge: challenge },
+      originalUrl: `/oauth/openid?code_challenge=${challenge}`,
+      url: `/oauth/openid?code_challenge=${challenge}`,
+    });
+
+    const result = await storeAndStripChallenge(cache, req, 'test-state', 'openid');
+
+    expect(result).toBe(false);
+    expect(req.query.code_challenge).toBe(challenge);
+    expect(req.originalUrl).toBe(`/oauth/openid?code_challenge=${challenge}`);
+    expect(req.url).toBe(`/oauth/openid?code_challenge=${challenge}`);
+  });
+
+  it('reads code_challenge before stripping (ordering guarantee)', async () => {
+    const cache = new Keyv();
+    const setSpy = jest.spyOn(cache, 'set');
+    const req = makeReq({
+      query: { code_challenge: challenge },
+      originalUrl: `/oauth/openid?code_challenge=${challenge}`,
+      url: `/oauth/openid?code_challenge=${challenge}`,
+    });
+
+    await storeAndStripChallenge(cache, req, 'test-state', 'openid');
+
+    const storedValue = setSpy.mock.calls[0][1];
+    expect(storedValue).toBe(challenge);
+  });
+});
diff --git a/packages/api/src/auth/exchange.ts b/packages/api/src/auth/exchange.ts
index f304ac6532..931c251d55 100644
--- a/packages/api/src/auth/exchange.ts
+++ b/packages/api/src/auth/exchange.ts
@@ -168,6 +168,73 @@ export async function exchangeAdminCode(
   };
 }
 
+/** PKCE challenge cache TTL: 5 minutes (enough for user to authenticate with IdP) */
+export const PKCE_CHALLENGE_TTL = 5 * 60 * 1000;
+/** Regex pattern for valid PKCE challenges: 64 hex characters (SHA-256 hex digest) */
+export const PKCE_CHALLENGE_PATTERN = /^[a-f0-9]{64}$/;
+
+/** Removes `code_challenge` from a single URL string, preserving other query params. */
+const stripChallengeFromUrl = (url: string): string =>
+  url.replace(/\?code_challenge=[^&]*&/, '?').replace(/[?&]code_challenge=[^&]*/, '');
+
+/** Minimal request shape needed by {@link stripCodeChallenge}. */
+export interface PkceStrippableRequest {
+  query: Record<string, unknown>;
+  originalUrl: string;
+  url: string;
+}
+
+/**
+ * Strips `code_challenge` from the request query and URL strings.
+ *
+ * openid-client v6's Passport Strategy uses `currentUrl.searchParams.size === 0`
+ * to distinguish an initial authorization request from an OAuth callback.
+ * The admin-panel-specific `code_challenge` query parameter would cause the
+ * strategy to misclassify the request as a callback and return 401.
+ *
+ * Applied defensively to all providers to ensure the admin-panel-private
+ * `code_challenge` parameter never reaches any Passport strategy.
+ */
+export function stripCodeChallenge(req: PkceStrippableRequest): void {
+  delete req.query.code_challenge;
+  req.originalUrl = stripChallengeFromUrl(req.originalUrl);
+  req.url = stripChallengeFromUrl(req.url);
+}
+
+/**
+ * Stores the admin-panel PKCE challenge in cache, then strips `code_challenge`
+ * from the request so it doesn't interfere with the Passport strategy.
+ *
+ * Must be called before `passport.authenticate()` — the two operations are
+ * logically atomic: read the challenge from the query, persist it, then remove
+ * the parameter from the request URL.
+ * @param cache - The Keyv cache instance for storing PKCE challenges.
+ * @param req - The Express request to read and mutate.
+ * @param state - The OAuth state value (cache key).
+ * @param provider - Provider name for logging.
+ * @returns True if stored (or no challenge provided); false on cache failure.
+ */
+export async function storeAndStripChallenge(
+  cache: Keyv,
+  req: PkceStrippableRequest,
+  state: string,
+  provider: string,
+): Promise<boolean> {
+  const { code_challenge: codeChallenge } = req.query;
+  if (typeof codeChallenge !== 'string' || !PKCE_CHALLENGE_PATTERN.test(codeChallenge)) {
+    stripCodeChallenge(req);
+    return true;
+  }
+  try {
+    await cache.set(`pkce:${state}`, codeChallenge, PKCE_CHALLENGE_TTL);
+    stripCodeChallenge(req);
+    return true;
+  } catch (err) {
+    logger.error(`[admin/oauth/${provider}] Failed to store PKCE challenge:`, err);
+    return false;
+  }
+}
+
 /**
  * Checks if the redirect URI is for the admin panel (cross-origin).
  * Uses proper URL parsing to compare origins, handling edge cases where
diff --git a/packages/api/src/mcp/MCPConnectionFactory.ts b/packages/api/src/mcp/MCPConnectionFactory.ts
index eb62514a4e..c517140b8a 100644
--- a/packages/api/src/mcp/MCPConnectionFactory.ts
+++ b/packages/api/src/mcp/MCPConnectionFactory.ts
@@ -351,10 +351,13 @@ export class MCPConnectionFactory {
             config?.oauth_headers ?? {},
             config?.oauth,
             this.allowedDomains,
+            // Only reuse stored client when deleteTokens is available for stale-client cleanup
+            this.tokenMethods?.deleteTokens ? this.tokenMethods.findToken : undefined,
           );
 
           if (existingFlow) {
-            const oldState = (existingFlow.metadata as MCPOAuthFlowMetadata)?.state;
+            const oldMeta = existingFlow.metadata as MCPOAuthFlowMetadata | undefined;
+            const oldState = oldMeta?.state;
             await this.flowManager!.deleteFlow(newFlowId, 'mcp_oauth');
             if (oldState) {
               await MCPOAuthHandler.deleteStateMapping(oldState, this.flowManager!);
@@ -368,9 +371,12 @@ export class MCPConnectionFactory {
 
           // Start monitoring in background — createFlow will find the existing PENDING state
           // written by initFlow above, so metadata arg is unused (pass {} to make that explicit)
-          this.flowManager!.createFlow(newFlowId, 'mcp_oauth', {}, this.signal).catch((error) => {
-            logger.debug(`${this.logPrefix} OAuth flow monitor ended`, error);
-          });
+          this.flowManager!.createFlow(newFlowId, 'mcp_oauth', {}, this.signal).catch(
+            async (error) => {
+              logger.debug(`${this.logPrefix} OAuth flow monitor ended`, error);
+              await this.clearStaleClientIfRejected(flowMetadata.reusedStoredClient, error);
+            },
+          );
 
           if (this.oauthStart) {
             logger.info(`${this.logPrefix} OAuth flow started, issuing authorization URL`);
@@ -412,7 +418,7 @@ export class MCPConnectionFactory {
       if (result?.tokens) {
         connection.emit('oauthHandled');
       } else {
-        // OAuth failed, emit oauthFailed to properly reject the promise
+        await this.clearStaleClientIfRejected(result?.reusedStoredClient, result?.error);
         logger.warn(`${this.logPrefix} OAuth failed, emitting oauthFailed event`);
         connection.emit('oauthFailed', new Error('OAuth authentication failed'));
       }
@@ -466,6 +472,49 @@ export class MCPConnectionFactory {
     }
   }
 
+  /** Clears stored client registration if the error indicates client rejection */
+  private async clearStaleClientIfRejected(
+    reusedStoredClient: boolean | undefined,
+    error: unknown,
+  ): Promise<void> {
+    if (!reusedStoredClient || !this.tokenMethods?.deleteTokens) {
+      return;
+    }
+    if (!MCPConnectionFactory.isClientRejection(error)) {
+      return;
+    }
+    await MCPTokenStorage.deleteClientRegistration({
+      userId: this.userId!,
+      serverName: this.serverName,
+      deleteTokens: this.tokenMethods.deleteTokens,
+    }).catch((err) => {
+      logger.warn(`${this.logPrefix} Failed to clear stale client registration`, err);
+    });
+  }
+
+  /**
+   * Checks whether an error indicates the OAuth client registration was rejected.
+   * Includes RFC 6749 §5.2 standard codes (`invalid_client`, `unauthorized_client`)
+   * and known vendor-specific patterns (Okta: `client_id mismatch`, Auth0: `client not found`,
+   * generic: `unknown client`).
+   */
+  static isClientRejection(error: unknown): boolean {
+    if (!error || typeof error !== 'object') {
+      return false;
+    }
+    if ('message' in error && typeof error.message === 'string') {
+      const msg = error.message.toLowerCase();
+      return (
+        msg.includes('invalid_client') ||
+        msg.includes('unauthorized_client') ||
+        msg.includes('client_id mismatch') ||
+        msg.includes('client not found') ||
+        msg.includes('unknown client')
+      );
+    }
+    return false;
+  }
+
   // Determines if an error indicates OAuth authentication is required
   private isOAuthError(error: unknown): boolean {
     if (!error || typeof error !== 'object') {
@@ -505,6 +554,8 @@ export class MCPConnectionFactory {
     tokens: MCPOAuthTokens | null;
     clientInfo?: OAuthClientInformation;
     metadata?: OAuthMetadata;
+    reusedStoredClient?: boolean;
+    error?: unknown;
   } | null> {
     const serverUrl = (this.serverConfig as t.SSEOptions | t.StreamableHTTPOptions).url;
     logger.debug(
@@ -519,6 +570,8 @@ export class MCPConnectionFactory {
       return null;
     }
 
+    let reusedStoredClient = false;
+
     try {
       logger.debug(`${this.logPrefix} Checking for existing OAuth flow for ${this.serverName}...`);
 
@@ -549,6 +602,7 @@ export class MCPConnectionFactory {
               await this.oauthStart(storedAuthUrl);
             }
 
+            reusedStoredClient = flowMeta?.reusedStoredClient === true;
             const tokens = await this.flowManager.createFlow(flowId, 'mcp_oauth', {}, this.signal);
             if (typeof this.oauthEnd === 'function') {
               await this.oauthEnd();
@@ -560,6 +614,7 @@ export class MCPConnectionFactory {
               tokens,
               clientInfo: flowMeta?.clientInfo,
               metadata: flowMeta?.metadata,
+              reusedStoredClient,
             };
           }
 
@@ -615,8 +670,11 @@ export class MCPConnectionFactory {
         this.serverConfig.oauth_headers ?? {},
         this.serverConfig.oauth,
         this.allowedDomains,
+        this.tokenMethods?.deleteTokens ? this.tokenMethods.findToken : undefined,
       );
 
+      reusedStoredClient = flowMetadata.reusedStoredClient === true;
+
       // Store flow state BEFORE redirecting so the callback can find it
       const metadataWithUrl = { ...flowMetadata, authorizationUrl };
       await this.flowManager.initFlow(newFlowId, 'mcp_oauth', metadataWithUrl);
@@ -639,18 +697,15 @@ export class MCPConnectionFactory {
       }
       logger.info(`${this.logPrefix} OAuth flow completed, tokens received for ${this.serverName}`);
 
-      /** Client information from the flow metadata */
-      const clientInfo = flowMetadata?.clientInfo;
-      const metadata = flowMetadata?.metadata;
-
       return {
         tokens,
-        clientInfo,
-        metadata,
+        clientInfo: flowMetadata.clientInfo,
+        metadata: flowMetadata.metadata,
+        reusedStoredClient,
       };
     } catch (error) {
       logger.error(`${this.logPrefix} Failed to complete OAuth flow for ${this.serverName}`, error);
-      return null;
+      return { tokens: null, reusedStoredClient, error };
     }
   }
 }
diff --git a/packages/api/src/mcp/__tests__/MCPConnectionFactory.test.ts b/packages/api/src/mcp/__tests__/MCPConnectionFactory.test.ts
index 326b77789e..d90ca5b345 100644
--- a/packages/api/src/mcp/__tests__/MCPConnectionFactory.test.ts
+++ b/packages/api/src/mcp/__tests__/MCPConnectionFactory.test.ts
@@ -5,7 +5,7 @@ import type { MCPOAuthTokens } from '~/mcp/oauth';
 import type * as t from '~/mcp/types';
 import { MCPConnectionFactory } from '~/mcp/MCPConnectionFactory';
 import { MCPConnection } from '~/mcp/connection';
-import { MCPOAuthHandler } from '~/mcp/oauth';
+import { MCPOAuthHandler, MCPTokenStorage } from '~/mcp/oauth';
 import { processMCPEnv } from '~/utils';
 
 jest.mock('~/mcp/connection');
@@ -24,6 +24,7 @@ const mockLogger = logger as jest.Mocked<typeof logger>;
 const mockProcessMCPEnv = processMCPEnv as jest.MockedFunction<typeof processMCPEnv>;
 const mockMCPConnection = MCPConnection as jest.MockedClass<typeof MCPConnection>;
 const mockMCPOAuthHandler = MCPOAuthHandler as jest.Mocked<typeof MCPOAuthHandler>;
+const mockMCPTokenStorage = MCPTokenStorage as jest.Mocked<typeof MCPTokenStorage>;
 
 describe('MCPConnectionFactory', () => {
   let mockUser: IUser | undefined;
@@ -270,6 +271,7 @@ describe('MCPConnectionFactory', () => {
         {},
         undefined,
         undefined,
+        oauthOptions.tokenMethods.findToken,
       );
 
       // initFlow must be awaited BEFORE the redirect to guarantee state is stored
@@ -292,6 +294,78 @@ describe('MCPConnectionFactory', () => {
       );
     });
 
+    it('should clear stale client registration when returnOnOAuth flow fails with client rejection', async () => {
+      const basicOptions = {
+        serverName: 'test-server',
+        serverConfig: {
+          ...mockServerConfig,
+          url: 'https://api.example.com',
+          type: 'sse' as const,
+        } as t.SSEOptions,
+      };
+
+      const deleteTokensSpy = jest.fn().mockResolvedValue({ acknowledged: true, deletedCount: 1 });
+      const oauthOptions = {
+        useOAuth: true as const,
+        user: mockUser,
+        flowManager: mockFlowManager,
+        returnOnOAuth: true,
+        oauthStart: jest.fn(),
+        tokenMethods: {
+          findToken: jest.fn(),
+          createToken: jest.fn(),
+          updateToken: jest.fn(),
+          deleteTokens: deleteTokensSpy,
+        },
+      };
+
+      const mockFlowData = {
+        authorizationUrl: 'https://auth.example.com',
+        flowId: 'flow123',
+        flowMetadata: {
+          serverName: 'test-server',
+          userId: 'user123',
+          serverUrl: 'https://api.example.com',
+          state: 'random-state',
+          clientInfo: { client_id: 'stale-client' },
+          reusedStoredClient: true,
+        },
+      };
+
+      mockMCPOAuthHandler.initiateOAuthFlow.mockResolvedValue(mockFlowData);
+      mockMCPTokenStorage.deleteClientRegistration.mockResolvedValue(undefined);
+      // createFlow rejects with invalid_client — simulating stale client rejection
+      mockFlowManager.createFlow.mockRejectedValue(new Error('invalid_client'));
+      mockConnectionInstance.isConnected.mockResolvedValue(false);
+
+      let oauthRequiredHandler: (data: Record<string, unknown>) => Promise<void>;
+      mockConnectionInstance.on.mockImplementation((event, handler) => {
+        if (event === 'oauthRequired') {
+          oauthRequiredHandler = handler as (data: Record<string, unknown>) => Promise<void>;
+        }
+        return mockConnectionInstance;
+      });
+
+      try {
+        await MCPConnectionFactory.create(basicOptions, oauthOptions);
+      } catch {
+        // Expected
+      }
+
+      await oauthRequiredHandler!({ serverUrl: 'https://api.example.com' });
+
+      // Drain microtasks so the background .catch() handler completes
+      await new Promise((r) => setImmediate(r));
+
+      // deleteClientRegistration should have been called via clearStaleClientIfRejected
+      expect(mockMCPTokenStorage.deleteClientRegistration).toHaveBeenCalledWith(
+        expect.objectContaining({
+          userId: 'user123',
+          serverName: 'test-server',
+        }),
+      );
+    });
+
     it('should skip new OAuth flow initiation when a PENDING flow already exists (returnOnOAuth)', async () => {
       const basicOptions = {
         serverName: 'test-server',
diff --git a/packages/api/src/mcp/__tests__/MCPOAuthClientRegistrationReuse.test.ts b/packages/api/src/mcp/__tests__/MCPOAuthClientRegistrationReuse.test.ts
new file mode 100644
index 0000000000..75cf4147b2
--- /dev/null
+++ b/packages/api/src/mcp/__tests__/MCPOAuthClientRegistrationReuse.test.ts
@@ -0,0 +1,508 @@
+/**
+ * Tests for MCP OAuth client registration reuse on reconnection.
+ *
+ * Documents the client_id mismatch bug in horizontally scaled deployments:
+ *
+ * When LibreChat runs with multiple replicas (e.g., 3 behind a load balancer),
+ * each replica independently calls registerClient() on the OAuth server's /register
+ * endpoint, getting a different client_id. The check-then-act race between the
+ * PENDING flow check and storing the flow state means that even with a shared
+ * Redis-backed flow store, replicas slip through before any has stored PENDING:
+ *
+ *   Replica A: getFlowState() → null → initiateOAuthFlow() → registers client_A
+ *   Replica B: getFlowState() → null → initiateOAuthFlow() → registers client_B
+ *   Replica A: initFlow(metadata with client_A) → stored in Redis
+ *   Replica B: initFlow(metadata with client_B) → OVERWRITES in Redis
+ *   User completes OAuth in browser with client_A in the URL
+ *   Callback reads Redis → finds client_B → token exchange fails: "client_id mismatch"
+ *
+ * The fix stabilizes reconnection flows: before calling registerClient(), check
+ * MongoDB (shared across replicas) for an existing client registration from a prior
+ * successful OAuth flow and reuse it. This eliminates redundant /register calls on
+ * reconnection. Note: the first-time concurrent auth race is NOT addressed by this
+ * fix and would require a distributed lock (e.g., Redis SETNX) around registration.
+ */
+
+import type { OAuthClientInformation } from '@modelcontextprotocol/sdk/shared/auth.js';
+import type { OAuthTestServer } from './helpers/oauthTestServer';
+import { InMemoryTokenStore, createOAuthMCPServer } from './helpers/oauthTestServer';
+import { MCPConnectionFactory } from '~/mcp/MCPConnectionFactory';
+import { MCPOAuthHandler, MCPTokenStorage } from '~/mcp/oauth';
+
+jest.mock('@librechat/data-schemas', () => ({
+  logger: {
+    info: jest.fn(),
+    warn: jest.fn(),
+    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:/, '')),
+}));
+
+jest.mock('~/auth', () => ({
+  createSSRFSafeUndiciConnect: jest.fn(() => undefined),
+  resolveHostnameSSRF: jest.fn(async () => false),
+  isSSRFTarget: jest.fn(async () => false),
+  isOAuthUrlAllowed: jest.fn(() => true),
+}));
+
+jest.mock('~/mcp/mcpConfig', () => ({
+  mcpConfig: { CONNECTION_CHECK_TTL: 0, USER_CONNECTION_IDLE_TIMEOUT: 30 * 60 * 1000 },
+}));
+
+describe('MCPOAuthHandler - client registration reuse on reconnection', () => {
+  let server: OAuthTestServer | undefined;
+  let originalDomainServer: string | undefined;
+
+  beforeEach(() => {
+    originalDomainServer = process.env.DOMAIN_SERVER;
+    process.env.DOMAIN_SERVER = 'http://localhost:3080';
+  });
+
+  afterEach(async () => {
+    if (originalDomainServer !== undefined) {
+      process.env.DOMAIN_SERVER = originalDomainServer;
+    } else {
+      delete process.env.DOMAIN_SERVER;
+    }
+    if (server) {
+      await server.close();
+      server = undefined;
+    }
+    jest.clearAllMocks();
+  });
+
+  describe('Race condition reproduction: concurrent replicas re-register', () => {
+    it('should produce duplicate client registrations when two replicas initiate flows concurrently', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+
+      const [resultA, resultB] = await Promise.all([
+        MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {}),
+        MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {}),
+      ]);
+
+      expect(resultA.authorizationUrl).toBeTruthy();
+      expect(resultB.authorizationUrl).toBeTruthy();
+      expect(server.registeredClients.size).toBe(2);
+
+      const clientA = resultA.flowMetadata.clientInfo?.client_id;
+      const clientB = resultB.flowMetadata.clientInfo?.client_id;
+      expect(clientA).not.toBe(clientB);
+    });
+
+    it('should re-register on every sequential initiateOAuthFlow call (reconnections)', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+
+      await MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {});
+      expect(server.registeredClients.size).toBe(1);
+
+      await MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {});
+      expect(server.registeredClients.size).toBe(2);
+
+      await MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {});
+      expect(server.registeredClients.size).toBe(3);
+    });
+  });
+
+  describe('Client reuse via findToken on reconnection', () => {
+    it('should reuse an existing client registration when findToken returns stored client info', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      const firstResult = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+      expect(server.registeredClients.size).toBe(1);
+      const firstClientId = firstResult.flowMetadata.clientInfo?.client_id;
+
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'test-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: firstResult.flowMetadata.clientInfo,
+        metadata: firstResult.flowMetadata.metadata,
+      });
+
+      const secondResult = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+
+      expect(server.registeredClients.size).toBe(1);
+      expect(secondResult.flowMetadata.clientInfo?.client_id).toBe(firstClientId);
+      expect(secondResult.flowMetadata.reusedStoredClient).toBe(true);
+    });
+
+    it('should reuse the same client when two reconnections fire concurrently with pre-seeded token', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      const initialResult = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+      const storedClientId = initialResult.flowMetadata.clientInfo?.client_id;
+
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'test-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: initialResult.flowMetadata.clientInfo,
+        metadata: initialResult.flowMetadata.metadata,
+      });
+
+      const [resultA, resultB] = await Promise.all([
+        MCPOAuthHandler.initiateOAuthFlow(
+          'test-server',
+          server.url,
+          'user-1',
+          {},
+          undefined,
+          undefined,
+          tokenStore.findToken,
+        ),
+        MCPOAuthHandler.initiateOAuthFlow(
+          'test-server',
+          server.url,
+          'user-1',
+          {},
+          undefined,
+          undefined,
+          tokenStore.findToken,
+        ),
+      ]);
+
+      // Both should reuse the stored client — only the initial registration should exist
+      expect(server.registeredClients.size).toBe(1);
+      expect(resultA.flowMetadata.clientInfo?.client_id).toBe(storedClientId);
+      expect(resultB.flowMetadata.clientInfo?.client_id).toBe(storedClientId);
+    });
+
+    it('should re-register when stored redirect_uri differs from current', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'old-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: {
+          client_id: 'old-client-id',
+          client_secret: 'old-secret',
+          redirect_uris: ['http://old-domain.com/api/mcp/test-server/oauth/callback'],
+        } as OAuthClientInformation & { redirect_uris: string[] },
+      });
+
+      const result = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+
+      expect(server.registeredClients.size).toBe(1);
+      expect(result.flowMetadata.clientInfo?.client_id).not.toBe('old-client-id');
+    });
+
+    it('should re-register when stored client has empty redirect_uris', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'old-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: {
+          client_id: 'empty-redirect-client',
+          client_secret: 'secret',
+          redirect_uris: [],
+        } as OAuthClientInformation & { redirect_uris: string[] },
+      });
+
+      const result = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+
+      // Should NOT reuse the client with empty redirect_uris — must re-register
+      expect(server.registeredClients.size).toBe(1);
+      expect(result.flowMetadata.clientInfo?.client_id).not.toBe('empty-redirect-client');
+    });
+
+    it('should fall back to registration when findToken lookup throws', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const failingFindToken = jest.fn().mockRejectedValue(new Error('DB connection lost'));
+
+      const result = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        failingFindToken,
+      );
+
+      expect(server.registeredClients.size).toBe(1);
+      expect(result.flowMetadata.clientInfo?.client_id).toBeTruthy();
+    });
+
+    it('should not reuse a stale client on retry after a failed flow', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      // Seed a stored client with a client_id that the OAuth server doesn't recognize,
+      // but with matching issuer and redirect_uri so reuse logic accepts it
+      const serverIssuer = `http://127.0.0.1:${server.port}`;
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'old-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: {
+          client_id: 'stale-client-that-oauth-server-deleted',
+          client_secret: 'stale-secret',
+          redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        } as OAuthClientInformation & { redirect_uris: string[] },
+        metadata: {
+          issuer: serverIssuer,
+          authorization_endpoint: `${serverIssuer}/authorize`,
+          token_endpoint: `${serverIssuer}/token`,
+        },
+      });
+
+      // First attempt: reuses the stale client (this is expected — we don't know it's stale yet)
+      const firstResult = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+      expect(firstResult.flowMetadata.clientInfo?.client_id).toBe(
+        'stale-client-that-oauth-server-deleted',
+      );
+      expect(firstResult.flowMetadata.reusedStoredClient).toBe(true);
+      expect(server.registeredClients.size).toBe(0);
+
+      // Simulate what MCPConnectionFactory does on failure when reusedStoredClient is set:
+      // clear the stored client registration so the next attempt does a fresh DCR
+      await MCPTokenStorage.deleteClientRegistration({
+        userId: 'user-1',
+        serverName: 'test-server',
+        deleteTokens: tokenStore.deleteTokens,
+      });
+
+      // Second attempt (retry after failure): should do a fresh DCR
+      const secondResult = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+
+      expect(server.registeredClients.size).toBe(1);
+      expect(secondResult.flowMetadata.clientInfo?.client_id).not.toBe(
+        'stale-client-that-oauth-server-deleted',
+      );
+      expect(secondResult.flowMetadata.reusedStoredClient).toBeUndefined();
+    });
+
+    it('should re-register when stored client was issued by a different authorization server', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const tokenStore = new InMemoryTokenStore();
+
+      // Seed a stored client that was registered with a different issuer
+      await MCPTokenStorage.storeTokens({
+        userId: 'user-1',
+        serverName: 'test-server',
+        tokens: { access_token: 'old-token', token_type: 'Bearer' },
+        createToken: tokenStore.createToken,
+        updateToken: tokenStore.updateToken,
+        findToken: tokenStore.findToken,
+        clientInfo: {
+          client_id: 'old-issuer-client',
+          client_secret: 'secret',
+          redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        } as OAuthClientInformation & { redirect_uris: string[] },
+        metadata: {
+          issuer: 'https://old-auth-server.example.com',
+          authorization_endpoint: 'https://old-auth-server.example.com/authorize',
+          token_endpoint: 'https://old-auth-server.example.com/token',
+        },
+      });
+
+      const result = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        server.url,
+        'user-1',
+        {},
+        undefined,
+        undefined,
+        tokenStore.findToken,
+      );
+
+      // Should have registered a NEW client because the issuer changed
+      expect(server.registeredClients.size).toBe(1);
+      expect(result.flowMetadata.clientInfo?.client_id).not.toBe('old-issuer-client');
+      expect(result.flowMetadata.reusedStoredClient).toBeUndefined();
+    });
+
+    it('should not call getClientInfoAndMetadata when findToken is not provided', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000 });
+      const spy = jest.spyOn(MCPTokenStorage, 'getClientInfoAndMetadata');
+
+      await MCPOAuthHandler.initiateOAuthFlow('test-server', server.url, 'user-1', {});
+
+      expect(spy).not.toHaveBeenCalled();
+      spy.mockRestore();
+    });
+  });
+
+  describe('isClientRejection', () => {
+    it('should detect invalid_client errors', () => {
+      expect(MCPConnectionFactory.isClientRejection(new Error('invalid_client'))).toBe(true);
+      expect(
+        MCPConnectionFactory.isClientRejection(
+          new Error('OAuth token exchange failed: invalid_client'),
+        ),
+      ).toBe(true);
+    });
+
+    it('should detect unauthorized_client errors', () => {
+      expect(MCPConnectionFactory.isClientRejection(new Error('unauthorized_client'))).toBe(true);
+    });
+
+    it('should detect client_id mismatch errors', () => {
+      expect(
+        MCPConnectionFactory.isClientRejection(
+          new Error('Token exchange rejected: client_id mismatch'),
+        ),
+      ).toBe(true);
+    });
+
+    it('should detect client not found errors', () => {
+      expect(MCPConnectionFactory.isClientRejection(new Error('client not found'))).toBe(true);
+      expect(MCPConnectionFactory.isClientRejection(new Error('unknown client'))).toBe(true);
+    });
+
+    it('should not match unrelated errors', () => {
+      expect(MCPConnectionFactory.isClientRejection(new Error('timeout'))).toBe(false);
+      expect(MCPConnectionFactory.isClientRejection(new Error('Flow state not found'))).toBe(false);
+      expect(MCPConnectionFactory.isClientRejection(new Error('user denied access'))).toBe(false);
+      expect(MCPConnectionFactory.isClientRejection(null)).toBe(false);
+      expect(MCPConnectionFactory.isClientRejection(undefined)).toBe(false);
+    });
+  });
+
+  describe('Token exchange with enforced client_id', () => {
+    it('should reject token exchange when client_id does not match registered client', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000, enforceClientId: true });
+
+      // Register a real client via DCR
+      const regRes = await fetch(`${server.url}register`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ redirect_uris: ['http://localhost/callback'] }),
+      });
+      const registered = (await regRes.json()) as { client_id: string };
+
+      // Get an auth code bound to the registered client_id
+      const authRes = await fetch(
+        `${server.url}authorize?redirect_uri=http://localhost/callback&state=s1&client_id=${registered.client_id}`,
+        { redirect: 'manual' },
+      );
+      const location = authRes.headers.get('location') ?? '';
+      const code = new URL(location).searchParams.get('code');
+
+      // Try to exchange the code with a DIFFERENT (stale) client_id
+      const tokenRes = await fetch(`${server.url}token`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+        body: `grant_type=authorization_code&code=${code}&client_id=stale-client-id`,
+      });
+
+      expect(tokenRes.status).toBe(401);
+      const body = (await tokenRes.json()) as { error: string; error_description?: string };
+      expect(body.error).toBe('invalid_client');
+
+      // Verify isClientRejection would match this error
+      const errorMsg = body.error_description ?? body.error;
+      expect(MCPConnectionFactory.isClientRejection(new Error(errorMsg))).toBe(true);
+    });
+
+    it('should accept token exchange when client_id matches', async () => {
+      server = await createOAuthMCPServer({ tokenTTLMs: 60000, enforceClientId: true });
+
+      const regRes = await fetch(`${server.url}register`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ redirect_uris: ['http://localhost/callback'] }),
+      });
+      const registered = (await regRes.json()) as { client_id: string };
+
+      const authRes = await fetch(
+        `${server.url}authorize?redirect_uri=http://localhost/callback&state=s1&client_id=${registered.client_id}`,
+        { redirect: 'manual' },
+      );
+      const location = authRes.headers.get('location') ?? '';
+      const code = new URL(location).searchParams.get('code');
+
+      const tokenRes = await fetch(`${server.url}token`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+        body: `grant_type=authorization_code&code=${code}&client_id=${registered.client_id}`,
+      });
+
+      expect(tokenRes.status).toBe(200);
+      const body = (await tokenRes.json()) as { access_token: string };
+      expect(body.access_token).toBeTruthy();
+    });
+  });
+});
diff --git a/packages/api/src/mcp/__tests__/handler.test.ts b/packages/api/src/mcp/__tests__/handler.test.ts
index 31665ce8f7..87de316d17 100644
--- a/packages/api/src/mcp/__tests__/handler.test.ts
+++ b/packages/api/src/mcp/__tests__/handler.test.ts
@@ -20,6 +20,12 @@ jest.mock('@modelcontextprotocol/sdk/client/auth.js', () => ({
   exchangeAuthorization: jest.fn(),
 }));
 
+jest.mock('../../mcp/oauth/tokens', () => ({
+  MCPTokenStorage: {
+    getClientInfoAndMetadata: jest.fn(),
+  },
+}));
+
 import {
   startAuthorization,
   discoverAuthorizationServerMetadata,
@@ -27,6 +33,7 @@ import {
   registerClient,
   exchangeAuthorization,
 } from '@modelcontextprotocol/sdk/client/auth.js';
+import { MCPTokenStorage } from '../../mcp/oauth/tokens';
 import { FlowStateManager } from '../../flow/manager';
 
 const mockStartAuthorization = startAuthorization as jest.MockedFunction<typeof startAuthorization>;
@@ -42,6 +49,10 @@ const mockRegisterClient = registerClient as jest.MockedFunction<typeof register
 const mockExchangeAuthorization = exchangeAuthorization as jest.MockedFunction<
   typeof exchangeAuthorization
 >;
+const mockGetClientInfoAndMetadata =
+  MCPTokenStorage.getClientInfoAndMetadata as jest.MockedFunction<
+    typeof MCPTokenStorage.getClientInfoAndMetadata
+  >;
 
 describe('MCPOAuthHandler - Configurable OAuth Metadata', () => {
   const mockServerName = 'test-server';
@@ -1391,6 +1402,348 @@ describe('MCPOAuthHandler - Configurable OAuth Metadata', () => {
     });
   });
 
+  describe('Client Registration Reuse', () => {
+    const originalFetch = global.fetch;
+    const mockFetch = jest.fn();
+
+    beforeEach(() => {
+      jest.clearAllMocks();
+      global.fetch = mockFetch as unknown as typeof fetch;
+      mockFetch.mockResolvedValue({ ok: true, json: async () => ({}) } as Response);
+      process.env.DOMAIN_SERVER = 'http://localhost:3080';
+    });
+
+    afterAll(() => {
+      global.fetch = originalFetch;
+    });
+
+    const mockFindToken = jest.fn();
+
+    it('should reuse existing client registration when findToken is provided and client exists', async () => {
+      const existingClientInfo = {
+        client_id: 'existing-client-id',
+        client_secret: 'existing-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        token_endpoint_auth_method: 'client_secret_basic',
+      };
+
+      mockGetClientInfoAndMetadata.mockResolvedValueOnce({
+        clientInfo: existingClientInfo,
+        clientMetadata: { issuer: 'https://example.com' },
+      });
+
+      // Mock resource metadata discovery to fail
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      // Mock authorization server metadata discovery
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=existing-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      const result = await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+        undefined,
+        mockFindToken,
+      );
+
+      // Should NOT have called registerClient since we reused the existing one
+      expect(mockRegisterClient).not.toHaveBeenCalled();
+
+      // Should have used the existing client info for startAuthorization
+      expect(mockStartAuthorization).toHaveBeenCalledWith(
+        'https://example.com/mcp',
+        expect.objectContaining({
+          clientInformation: existingClientInfo,
+        }),
+      );
+
+      expect(result.authorizationUrl).toBeDefined();
+      expect(result.flowId).toBeDefined();
+    });
+
+    it('should register a new client when findToken is provided but no existing registration found', async () => {
+      mockGetClientInfoAndMetadata.mockResolvedValueOnce(null);
+
+      // Mock resource metadata discovery to fail
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      // Mock authorization server metadata discovery
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockRegisterClient.mockResolvedValueOnce({
+        client_id: 'new-client-id',
+        client_secret: 'new-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        logo_uri: undefined,
+        tos_uri: undefined,
+      });
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=new-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+        undefined,
+        mockFindToken,
+      );
+
+      // Should have called registerClient since no existing registration was found
+      expect(mockRegisterClient).toHaveBeenCalled();
+    });
+
+    it('should register a new client when findToken is not provided', async () => {
+      // Mock resource metadata discovery to fail
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      // Mock authorization server metadata discovery
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockRegisterClient.mockResolvedValueOnce({
+        client_id: 'new-client-id',
+        client_secret: 'new-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        logo_uri: undefined,
+        tos_uri: undefined,
+      });
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=new-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      // No findToken passed
+      await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+      );
+
+      // Should NOT have tried to look up existing registration
+      expect(mockGetClientInfoAndMetadata).not.toHaveBeenCalled();
+
+      // Should have called registerClient
+      expect(mockRegisterClient).toHaveBeenCalled();
+    });
+
+    it('should fall back to registration when getClientInfoAndMetadata throws', async () => {
+      mockGetClientInfoAndMetadata.mockRejectedValueOnce(new Error('DB error'));
+
+      // Mock resource metadata discovery to fail
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      // Mock authorization server metadata discovery
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockRegisterClient.mockResolvedValueOnce({
+        client_id: 'new-client-id',
+        client_secret: 'new-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        logo_uri: undefined,
+        tos_uri: undefined,
+      });
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=new-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+        undefined,
+        mockFindToken,
+      );
+
+      // Should have fallen back to registerClient
+      expect(mockRegisterClient).toHaveBeenCalled();
+    });
+
+    it('should re-register when stored redirect_uri differs from current configuration', async () => {
+      const existingClientInfo = {
+        client_id: 'existing-client-id',
+        client_secret: 'existing-client-secret',
+        redirect_uris: ['http://old-domain.com/api/mcp/test-server/oauth/callback'],
+        token_endpoint_auth_method: 'client_secret_basic',
+      };
+
+      mockGetClientInfoAndMetadata.mockResolvedValueOnce({
+        clientInfo: existingClientInfo,
+        clientMetadata: {},
+      });
+
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockRegisterClient.mockResolvedValueOnce({
+        client_id: 'new-client-id',
+        client_secret: 'new-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        logo_uri: undefined,
+        tos_uri: undefined,
+      });
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=new-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+        undefined,
+        mockFindToken,
+      );
+
+      expect(mockRegisterClient).toHaveBeenCalled();
+      expect(mockStartAuthorization).toHaveBeenCalledWith(
+        'https://example.com/mcp',
+        expect.objectContaining({
+          clientInformation: expect.objectContaining({
+            client_id: 'new-client-id',
+          }),
+        }),
+      );
+    });
+
+    it('should re-register when stored client has empty redirect_uris', async () => {
+      const existingClientInfo = {
+        client_id: 'empty-redirect-client',
+        client_secret: 'secret',
+        redirect_uris: [],
+      };
+
+      mockGetClientInfoAndMetadata.mockResolvedValueOnce({
+        clientInfo: existingClientInfo,
+        clientMetadata: {},
+      });
+
+      mockDiscoverOAuthProtectedResourceMetadata.mockRejectedValueOnce(
+        new Error('No resource metadata'),
+      );
+
+      mockDiscoverAuthorizationServerMetadata.mockResolvedValueOnce({
+        issuer: 'https://example.com',
+        authorization_endpoint: 'https://example.com/authorize',
+        token_endpoint: 'https://example.com/token',
+        registration_endpoint: 'https://example.com/register',
+        response_types_supported: ['code'],
+        jwks_uri: 'https://example.com/.well-known/jwks.json',
+        subject_types_supported: ['public'],
+        id_token_signing_alg_values_supported: ['RS256'],
+      } as AuthorizationServerMetadata);
+
+      mockRegisterClient.mockResolvedValueOnce({
+        client_id: 'new-client-id',
+        client_secret: 'new-client-secret',
+        redirect_uris: ['http://localhost:3080/api/mcp/test-server/oauth/callback'],
+        logo_uri: undefined,
+        tos_uri: undefined,
+      });
+
+      mockStartAuthorization.mockResolvedValueOnce({
+        authorizationUrl: new URL('https://example.com/authorize?client_id=new-client-id'),
+        codeVerifier: 'test-code-verifier',
+      });
+
+      await MCPOAuthHandler.initiateOAuthFlow(
+        'test-server',
+        'https://example.com/mcp',
+        'user-123',
+        {},
+        undefined,
+        undefined,
+        mockFindToken,
+      );
+
+      expect(mockRegisterClient).toHaveBeenCalled();
+      expect(mockStartAuthorization).toHaveBeenCalledWith(
+        'https://example.com/mcp',
+        expect.objectContaining({
+          clientInformation: expect.objectContaining({
+            client_id: 'new-client-id',
+          }),
+        }),
+      );
+    });
+  });
+
   describe('Fallback OAuth Metadata (Legacy Server Support)', () => {
     const originalFetch = global.fetch;
     const mockFetch = jest.fn();
diff --git a/packages/api/src/mcp/__tests__/helpers/oauthTestServer.ts b/packages/api/src/mcp/__tests__/helpers/oauthTestServer.ts
index 3b68b2ded4..34f968d4e2 100644
--- a/packages/api/src/mcp/__tests__/helpers/oauthTestServer.ts
+++ b/packages/api/src/mcp/__tests__/helpers/oauthTestServer.ts
@@ -59,6 +59,8 @@ export interface OAuthTestServerOptions {
   issueRefreshTokens?: boolean;
   refreshTokenTTLMs?: number;
   rotateRefreshTokens?: boolean;
+  /** When true, /token validates client_id against the registered client that initiated /authorize */
+  enforceClientId?: boolean;
 }
 
 export interface OAuthTestServer {
@@ -81,6 +83,17 @@ async function readRequestBody(req: http.IncomingMessage): Promise<string> {
   return Buffer.concat(chunks).toString();
 }
 
+function parseBasicAuth(
+  header: string | undefined,
+): { clientId: string; clientSecret: string } | null {
+  if (!header?.startsWith('Basic ')) {
+    return null;
+  }
+  const decoded = Buffer.from(header.slice(6), 'base64').toString();
+  const [clientId, clientSecret] = decoded.split(':');
+  return clientId ? { clientId, clientSecret: clientSecret ?? '' } : null;
+}
+
 function parseTokenRequest(body: string, contentType: string | undefined): URLSearchParams | null {
   if (contentType?.includes('application/x-www-form-urlencoded')) {
     return new URLSearchParams(body);
@@ -100,6 +113,7 @@ export async function createOAuthMCPServer(
     issueRefreshTokens = false,
     refreshTokenTTLMs = 365 * 24 * 60 * 60 * 1000,
     rotateRefreshTokens = false,
+    enforceClientId = false,
   } = options;
 
   const sessions = new Map<string, StreamableHTTPServerTransport>();
@@ -107,7 +121,10 @@ export async function createOAuthMCPServer(
   const tokenIssueTimes = new Map<string, number>();
   const issuedRefreshTokens = new Map<string, string>();
   const refreshTokenIssueTimes = new Map<string, number>();
-  const authCodes = new Map<string, { codeChallenge?: string; codeChallengeMethod?: string }>();
+  const authCodes = new Map<
+    string,
+    { codeChallenge?: string; codeChallengeMethod?: string; clientId?: string }
+  >();
   const registeredClients = new Map<string, { client_id: string; client_secret: string }>();
 
   let port = 0;
@@ -155,7 +172,8 @@ export async function createOAuthMCPServer(
       const code = randomUUID();
       const codeChallenge = url.searchParams.get('code_challenge') ?? undefined;
       const codeChallengeMethod = url.searchParams.get('code_challenge_method') ?? undefined;
-      authCodes.set(code, { codeChallenge, codeChallengeMethod });
+      const clientId = url.searchParams.get('client_id') ?? undefined;
+      authCodes.set(code, { codeChallenge, codeChallengeMethod, clientId });
       const redirectUri = url.searchParams.get('redirect_uri') ?? '';
       const state = url.searchParams.get('state') ?? '';
       res.writeHead(302, {
@@ -202,6 +220,23 @@ export async function createOAuthMCPServer(
           }
         }
 
+        if (enforceClientId && codeData.clientId) {
+          const requestClientId =
+            params.get('client_id') ?? parseBasicAuth(req.headers.authorization)?.clientId;
+          if (!requestClientId || !registeredClients.has(requestClientId)) {
+            res.writeHead(401, { 'Content-Type': 'application/json' });
+            res.end(JSON.stringify({ error: 'invalid_client' }));
+            return;
+          }
+          if (requestClientId !== codeData.clientId) {
+            res.writeHead(401, { 'Content-Type': 'application/json' });
+            res.end(
+              JSON.stringify({ error: 'invalid_client', error_description: 'client_id mismatch' }),
+            );
+            return;
+          }
+        }
+
         authCodes.delete(code);
 
         const accessToken = randomUUID();
@@ -439,6 +474,25 @@ export class InMemoryTokenStore {
     this.tokens.delete(this.key(filter));
   };
 
+  deleteTokens = async (query: {
+    userId?: string;
+    type?: string;
+    identifier?: string;
+  }): Promise<{ acknowledged: boolean; deletedCount: number }> => {
+    let deletedCount = 0;
+    for (const [key, token] of this.tokens.entries()) {
+      const match =
+        (!query.userId || token.userId === query.userId) &&
+        (!query.type || token.type === query.type) &&
+        (!query.identifier || token.identifier === query.identifier);
+      if (match) {
+        this.tokens.delete(key);
+        deletedCount++;
+      }
+    }
+    return { acknowledged: true, deletedCount };
+  };
+
   getAll(): InMemoryToken[] {
     return [...this.tokens.values()];
   }
diff --git a/packages/api/src/mcp/oauth/handler.ts b/packages/api/src/mcp/oauth/handler.ts
index e128dec308..ccca5b1945 100644
--- a/packages/api/src/mcp/oauth/handler.ts
+++ b/packages/api/src/mcp/oauth/handler.ts
@@ -10,6 +10,7 @@ import {
   discoverOAuthProtectedResourceMetadata,
 } from '@modelcontextprotocol/sdk/client/auth.js';
 import { TokenExchangeMethodEnum, type MCPOptions } from 'librechat-data-provider';
+import type { TokenMethods } from '@librechat/data-schemas';
 import type { FlowStateManager } from '~/flow/manager';
 import type {
   OAuthClientInformation,
@@ -25,6 +26,7 @@ import {
   inferClientAuthMethod,
 } from './methods';
 import { isSSRFTarget, resolveHostnameSSRF, isOAuthUrlAllowed } from '~/auth';
+import { MCPTokenStorage } from './tokens';
 import { sanitizeUrlForLogging } from '~/mcp/utils';
 
 /** Type for the OAuth metadata from the SDK */
@@ -368,6 +370,7 @@ export class MCPOAuthHandler {
     oauthHeaders: Record<string, string>,
     config?: MCPOptions['oauth'],
     allowedDomains?: string[] | null,
+    findToken?: TokenMethods['findToken'],
   ): Promise<{ authorizationUrl: string; flowId: string; flowMetadata: MCPOAuthFlowMetadata }> {
     logger.debug(
       `[MCPOAuth] initiateOAuthFlow called for ${serverName} with URL: ${sanitizeUrlForLogging(serverUrl)}`,
@@ -494,18 +497,62 @@ export class MCPOAuthHandler {
       );
 
       const redirectUri = this.getDefaultRedirectUri(serverName);
-      logger.debug(`[MCPOAuth] Registering OAuth client with redirect URI: ${redirectUri}`);
+      logger.debug(`[MCPOAuth] Resolving OAuth client with redirect URI: ${redirectUri}`);
 
-      const clientInfo = await this.registerOAuthClient(
-        authServerUrl.toString(),
-        metadata,
-        oauthHeaders,
-        resourceMetadata,
-        redirectUri,
-        config?.token_exchange_method,
-      );
+      let clientInfo: OAuthClientInformation | undefined;
+      let reusedStoredClient = false;
 
-      logger.debug(`[MCPOAuth] Client registered with ID: ${clientInfo.client_id}`);
+      if (findToken) {
+        try {
+          const existing = await MCPTokenStorage.getClientInfoAndMetadata({
+            userId,
+            serverName,
+            findToken,
+          });
+          if (existing?.clientInfo?.client_id) {
+            const storedRedirectUri = (existing.clientInfo as OAuthClientInformation)
+              .redirect_uris?.[0];
+            const storedIssuer =
+              typeof existing.clientMetadata?.issuer === 'string'
+                ? existing.clientMetadata.issuer.replace(/\/+$/, '')
+                : null;
+            const currentIssuer = (metadata.issuer ?? authServerUrl.toString()).replace(/\/+$/, '');
+
+            if (!storedRedirectUri || storedRedirectUri !== redirectUri) {
+              logger.debug(
+                `[MCPOAuth] Stored redirect_uri "${storedRedirectUri}" differs from current "${redirectUri}", will re-register`,
+              );
+            } else if (!storedIssuer || storedIssuer !== currentIssuer) {
+              logger.debug(
+                `[MCPOAuth] Issuer mismatch (stored: ${storedIssuer ?? 'none'}, current: ${currentIssuer}), will re-register`,
+              );
+            } else {
+              logger.debug(
+                `[MCPOAuth] Reusing existing client registration: ${existing.clientInfo.client_id}`,
+              );
+              clientInfo = existing.clientInfo;
+              reusedStoredClient = true;
+            }
+          }
+        } catch (error) {
+          logger.warn(
+            `[MCPOAuth] Failed to look up existing client registration, falling back to new registration`,
+            { error, serverName, userId },
+          );
+        }
+      }
+
+      if (!clientInfo) {
+        clientInfo = await this.registerOAuthClient(
+          authServerUrl.toString(),
+          metadata,
+          oauthHeaders,
+          resourceMetadata,
+          redirectUri,
+          config?.token_exchange_method,
+        );
+        logger.debug(`[MCPOAuth] Client registered with ID: ${clientInfo.client_id}`);
+      }
 
       /** Authorization Scope */
       const scope =
@@ -575,6 +622,7 @@ export class MCPOAuthHandler {
         metadata,
         resourceMetadata,
         ...(Object.keys(oauthHeaders).length > 0 && { oauthHeaders }),
+        ...(reusedStoredClient && { reusedStoredClient }),
       };
 
       logger.debug(
diff --git a/packages/api/src/mcp/oauth/tokens.ts b/packages/api/src/mcp/oauth/tokens.ts
index 1e31a64511..61b442ca8c 100644
--- a/packages/api/src/mcp/oauth/tokens.ts
+++ b/packages/api/src/mcp/oauth/tokens.ts
@@ -476,6 +476,26 @@ export class MCPTokenStorage {
     };
   }
 
+  /** Deletes only the stored client registration for a specific user and server */
+  static async deleteClientRegistration({
+    userId,
+    serverName,
+    deleteTokens,
+  }: {
+    userId: string;
+    serverName: string;
+    deleteTokens: TokenMethods['deleteTokens'];
+  }): Promise<void> {
+    const identifier = `mcp:${serverName}`;
+    await deleteTokens({
+      userId,
+      type: 'mcp_oauth_client',
+      identifier: `${identifier}:client`,
+    });
+    const logPrefix = this.getLogPrefix(userId, serverName);
+    logger.debug(`${logPrefix} Cleared stored client registration`);
+  }
+
   /**
    * Deletes all OAuth-related tokens for a specific user and server
    */
diff --git a/packages/api/src/mcp/oauth/types.ts b/packages/api/src/mcp/oauth/types.ts
index bc5f53f60c..ee8ce2d76d 100644
--- a/packages/api/src/mcp/oauth/types.ts
+++ b/packages/api/src/mcp/oauth/types.ts
@@ -91,6 +91,8 @@ export interface MCPOAuthFlowMetadata extends FlowMetadata {
   authorizationUrl?: string;
   /** Custom headers for OAuth token exchange, persisted at flow initiation for the callback. */
   oauthHeaders?: Record<string, string>;
+  /** True when the flow reused a stored client registration from a prior successful OAuth flow */
+  reusedStoredClient?: boolean;
 }
 
 export interface MCPOAuthTokens extends OAuthTokens {
diff --git a/packages/client/src/hooks/useLocalize.ts b/packages/client/src/hooks/useLocalize.ts
index 83366cff16..cab3dd6547 100644
--- a/packages/client/src/hooks/useLocalize.ts
+++ b/packages/client/src/hooks/useLocalize.ts
@@ -1,21 +1,16 @@
-import { useEffect } from 'react';
+import { useCallback } from 'react';
 import { TOptions } from 'i18next';
-import { useAtomValue } from 'jotai';
 import { useTranslation } from 'react-i18next';
 import { resources } from '~/locales/i18n';
-import { langAtom } from '~/store';
 
 export type TranslationKeys = keyof typeof resources.en.translation;
 
+/** Language lifecycle is managed by the host app — do not add i18n.changeLanguage() calls here. */
 export default function useLocalize() {
-  const lang = useAtomValue(langAtom);
-  const { t, i18n } = useTranslation();
+  const { t } = useTranslation();
 
-  useEffect(() => {
-    if (i18n.language !== lang) {
-      i18n.changeLanguage(lang);
-    }
-  }, [lang, i18n]);
-
-  return (phraseKey: TranslationKeys, options?: TOptions) => t(phraseKey, options);
+  return useCallback(
+    (phraseKey: TranslationKeys, options?: TOptions) => t(phraseKey, options),
+    [t],
+  );
 }
diff --git a/packages/client/src/store.ts b/packages/client/src/store.ts
index 6e23be6e04..36a3f05844 100644
--- a/packages/client/src/store.ts
+++ b/packages/client/src/store.ts
@@ -1,7 +1,6 @@
 import { atom } from 'jotai';
 import { NotificationSeverity } from '~/common';
 
-export const langAtom = atom<string>('en');
 export const chatDirectionAtom = atom<string>('ltr');
 export const fontSizeAtom = atom<string>('text-base');
 
diff --git a/packages/data-provider/package.json b/packages/data-provider/package.json
index 67eebf9cad..725d780b09 100644
--- a/packages/data-provider/package.json
+++ b/packages/data-provider/package.json
@@ -1,6 +1,6 @@
 {
   "name": "librechat-data-provider",
-  "version": "0.8.406",
+  "version": "0.8.407",
   "description": "data services for librechat apps",
   "main": "dist/index.js",
   "module": "dist/index.es.js",
diff --git a/packages/data-provider/specs/config-schemas.spec.ts b/packages/data-provider/specs/config-schemas.spec.ts
index fabd35cec9..6e76bced06 100644
--- a/packages/data-provider/specs/config-schemas.spec.ts
+++ b/packages/data-provider/specs/config-schemas.spec.ts
@@ -1,10 +1,15 @@
 import {
-  endpointSchema,
   paramDefinitionSchema,
   agentsEndpointSchema,
   azureEndpointSchema,
+  endpointSchema,
+  configSchema,
+  interfaceSchema,
+  fileStorageSchema,
+  fileStrategiesSchema,
 } from '../src/config';
 import { tModelSpecPresetSchema, EModelEndpoint } from '../src/schemas';
+import { FileSources } from '../src/types/files';
 
 describe('paramDefinitionSchema', () => {
   it('accepts a minimal definition with only key', () => {
@@ -222,6 +227,109 @@ describe('endpointSchema deprecated fields', () => {
   });
 });
 
+describe('endpointSchema addParams validation', () => {
+  const validEndpoint = {
+    name: 'CustomEndpoint',
+    apiKey: 'test-key',
+    baseURL: 'https://api.example.com',
+    models: { default: ['model-1'] },
+  };
+  const nestedAddParams = {
+    provider: {
+      only: ['z-ai'],
+      quantizations: ['int4'],
+    },
+  };
+
+  it('accepts nested addParams objects and arrays', () => {
+    const result = endpointSchema.safeParse({
+      ...validEndpoint,
+      addParams: nestedAddParams,
+    });
+    expect(result.success).toBe(true);
+    if (result.success) {
+      expect(result.data.addParams).toEqual(nestedAddParams);
+    }
+  });
+
+  it('keeps configSchema validation intact with nested custom addParams', () => {
+    const result = configSchema.safeParse({
+      version: '1.0.0',
+      endpoints: {
+        custom: [
+          {
+            ...validEndpoint,
+            addParams: nestedAddParams,
+          },
+        ],
+      },
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('accepts boolean web_search in addParams', () => {
+    const result = endpointSchema.safeParse({
+      ...validEndpoint,
+      addParams: {
+        provider: {
+          only: ['z-ai'],
+        },
+        web_search: true,
+      },
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('accepts scalar addParams values', () => {
+    const result = endpointSchema.safeParse({
+      ...validEndpoint,
+      addParams: {
+        model: 'custom-model',
+        retries: 2,
+        metadata: null,
+      },
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('rejects non-boolean web_search objects in addParams', () => {
+    const result = endpointSchema.safeParse({
+      ...validEndpoint,
+      addParams: {
+        provider: {
+          only: ['z-ai'],
+        },
+        web_search: {
+          enabled: true,
+        },
+      },
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('rejects configSchema entries with non-boolean web_search objects in custom addParams', () => {
+    const result = configSchema.safeParse({
+      version: '1.0.0',
+      endpoints: {
+        custom: [
+          {
+            ...validEndpoint,
+            addParams: {
+              provider: {
+                only: ['z-ai'],
+              },
+              web_search: {
+                enabled: true,
+              },
+            },
+          },
+        ],
+      },
+    });
+    expect(result.success).toBe(false);
+  });
+});
+
 describe('agentsEndpointSchema', () => {
   it('does not accept baseURL', () => {
     const result = agentsEndpointSchema.safeParse({
@@ -251,4 +359,146 @@ describe('azureEndpointSchema', () => {
       expect(result.data).not.toHaveProperty('plugins');
     }
   });
+
+  it('accepts nested addParams in azure groups', () => {
+    const result = azureEndpointSchema.safeParse({
+      groups: [
+        {
+          group: 'test-group',
+          apiKey: 'test-key',
+          models: { 'gpt-4': true },
+          addParams: {
+            provider: {
+              only: ['z-ai'],
+            },
+          },
+        },
+      ],
+    });
+    expect(result.success).toBe(true);
+    if (result.success) {
+      expect(result.data.groups[0].addParams).toEqual({
+        provider: {
+          only: ['z-ai'],
+        },
+      });
+    }
+  });
+
+  it('accepts boolean web_search in azure addParams', () => {
+    const result = azureEndpointSchema.safeParse({
+      groups: [
+        {
+          group: 'test-group',
+          apiKey: 'test-key',
+          models: { 'gpt-4': true },
+          addParams: {
+            provider: {
+              only: ['z-ai'],
+            },
+            web_search: false,
+          },
+        },
+      ],
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('rejects non-boolean web_search objects in azure addParams', () => {
+    const result = azureEndpointSchema.safeParse({
+      groups: [
+        {
+          group: 'test-group',
+          apiKey: 'test-key',
+          models: { 'gpt-4': true },
+          addParams: {
+            provider: {
+              only: ['z-ai'],
+            },
+            web_search: {
+              enabled: true,
+            },
+          },
+        },
+      ],
+    });
+    expect(result.success).toBe(false);
+  });
+});
+
+describe('fileStorageSchema', () => {
+  const validStrategies = [
+    FileSources.local,
+    FileSources.firebase,
+    FileSources.s3,
+    FileSources.azure_blob,
+  ];
+  const invalidStrategies = [
+    FileSources.openai,
+    FileSources.azure,
+    FileSources.vectordb,
+    FileSources.execute_code,
+    FileSources.mistral_ocr,
+    FileSources.azure_mistral_ocr,
+    FileSources.vertexai_mistral_ocr,
+    FileSources.text,
+    FileSources.document_parser,
+  ];
+
+  for (const strategy of validStrategies) {
+    it(`accepts storage strategy "${strategy}"`, () => {
+      expect(fileStorageSchema.safeParse(strategy).success).toBe(true);
+    });
+  }
+
+  for (const strategy of invalidStrategies) {
+    it(`rejects processing strategy "${strategy}"`, () => {
+      expect(fileStorageSchema.safeParse(strategy).success).toBe(false);
+    });
+  }
+});
+
+describe('fileStrategiesSchema', () => {
+  it('accepts valid storage strategies for all sub-fields', () => {
+    const result = fileStrategiesSchema.safeParse({
+      default: FileSources.s3,
+      avatar: FileSources.local,
+      image: FileSources.firebase,
+      document: FileSources.azure_blob,
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('rejects processing strategies in sub-fields', () => {
+    const result = fileStrategiesSchema.safeParse({
+      default: FileSources.vectordb,
+    });
+    expect(result.success).toBe(false);
+  });
+});
+
+describe('configSchema fileStrategy', () => {
+  it('rejects a processing strategy as fileStrategy', () => {
+    const result = configSchema.safeParse({ version: '1.3.7', fileStrategy: FileSources.vectordb });
+    expect(result.success).toBe(false);
+  });
+
+  it('defaults fileStrategy to local when absent', () => {
+    const result = configSchema.safeParse({ version: '1.3.7' });
+    expect(result.success).toBe(true);
+    expect(result.data?.fileStrategy).toBe(FileSources.local);
+  });
+});
+
+describe('interfaceSchema', () => {
+  it('silently strips removed legacy fields', () => {
+    const result = interfaceSchema.parse({
+      endpointsMenu: true,
+      sidePanel: true,
+      modelSelect: false,
+    });
+    expect(result).not.toHaveProperty('endpointsMenu');
+    expect(result).not.toHaveProperty('sidePanel');
+    expect(result.modelSelect).toBe(false);
+  });
 });
diff --git a/packages/data-provider/src/api-endpoints.ts b/packages/data-provider/src/api-endpoints.ts
index 00e860422c..21f9cdc6a3 100644
--- a/packages/data-provider/src/api-endpoints.ts
+++ b/packages/data-provider/src/api-endpoints.ts
@@ -361,7 +361,8 @@ export const getAllPromptGroups = () => `${prompts()}/all`;
 
 /* Roles */
 export const roles = () => `${BASE_URL}/api/roles`;
-export const getRole = (roleName: string) => `${roles()}/${roleName.toLowerCase()}`;
+export const adminRoles = () => `${BASE_URL}/api/admin/roles`;
+export const getRole = (roleName: string) => `${roles()}/${encodeURIComponent(roleName)}`;
 export const updatePromptPermissions = (roleName: string) => `${getRole(roleName)}/prompts`;
 export const updateMemoryPermissions = (roleName: string) => `${getRole(roleName)}/memories`;
 export const updateAgentPermissions = (roleName: string) => `${getRole(roleName)}/agents`;
diff --git a/packages/data-provider/src/config.ts b/packages/data-provider/src/config.ts
index 98ac38499e..3d339a403b 100644
--- a/packages/data-provider/src/config.ts
+++ b/packages/data-provider/src/config.ts
@@ -63,14 +63,27 @@ export enum SettingsViews {
   advanced = 'advanced',
 }
 
+/** Validates any FileSources value — use for file metadata, DB records, and upload routing. */
 export const fileSourceSchema = z.nativeEnum(FileSources);
 
+/** Storage backend strategies only — use for config fields that set where files are stored. */
+const FILE_STORAGE_BACKENDS = [
+  FileSources.local,
+  FileSources.firebase,
+  FileSources.s3,
+  FileSources.azure_blob,
+] as const satisfies ReadonlyArray<FileSources>;
+
+export const fileStorageSchema = z.enum(FILE_STORAGE_BACKENDS);
+
+export type FileStorage = z.infer<typeof fileStorageSchema>;
+
 export const fileStrategiesSchema = z
   .object({
-    default: fileSourceSchema.optional(),
-    avatar: fileSourceSchema.optional(),
-    image: fileSourceSchema.optional(),
-    document: fileSourceSchema.optional(),
+    default: fileStorageSchema.optional(),
+    avatar: fileStorageSchema.optional(),
+    image: fileStorageSchema.optional(),
+    document: fileStorageSchema.optional(),
   })
   .optional();
 
@@ -116,13 +129,39 @@ export const modelConfigSchema = z
 
 export type TAzureModelConfig = z.infer<typeof modelConfigSchema>;
 
+const paramValueSchema: z.ZodType<unknown> = z.lazy(() =>
+  z.union([
+    z.string(),
+    z.number(),
+    z.boolean(),
+    z.null(),
+    z.array(paramValueSchema),
+    z.record(z.string(), paramValueSchema),
+  ]),
+);
+
+/** Validates addParams while keeping web_search aligned with current runtime boolean handling. */
+const addParamsSchema: z.ZodType<Record<string, unknown>> = z
+  .record(z.string(), paramValueSchema)
+  .superRefine((params, ctx) => {
+    if (params.web_search === undefined || typeof params.web_search === 'boolean') {
+      return;
+    }
+
+    ctx.addIssue({
+      code: z.ZodIssueCode.custom,
+      path: ['web_search'],
+      message: '`web_search` must be a boolean in addParams',
+    });
+  });
+
 export const azureBaseSchema = z.object({
   apiKey: z.string(),
   serverless: z.boolean().optional(),
   instanceName: z.string().optional(),
   deploymentName: z.string().optional(),
   assistants: z.boolean().optional(),
-  addParams: z.record(z.union([z.string(), z.number(), z.boolean(), z.null()])).optional(),
+  addParams: addParamsSchema.optional(),
   dropParams: z.array(z.string()).optional(),
   version: z.string().optional(),
   baseURL: z.string().optional(),
@@ -362,7 +401,7 @@ export const endpointSchema = baseEndpointSchema.merge(
     iconURL: z.string().optional(),
     modelDisplayLabel: z.string().optional(),
     headers: z.record(z.string()).optional(),
-    addParams: z.record(z.union([z.string(), z.number(), z.boolean(), z.null()])).optional(),
+    addParams: addParamsSchema.optional(),
     dropParams: z.array(z.string()).optional(),
     customParams: z
       .object({
@@ -657,10 +696,8 @@ export const interfaceSchema = z
     termsOfService: termsOfServiceSchema.optional(),
     customWelcome: z.string().optional(),
     mcpServers: mcpServersSchema.optional(),
-    endpointsMenu: z.boolean().optional(),
     modelSelect: z.boolean().optional(),
     parameters: z.boolean().optional(),
-    sidePanel: z.boolean().optional(),
     multiConvo: z.boolean().optional(),
     bookmarks: z.boolean().optional(),
     memories: z.boolean().optional(),
@@ -716,10 +753,8 @@ export const interfaceSchema = z
       .optional(),
   })
   .default({
-    endpointsMenu: true,
     modelSelect: true,
     parameters: true,
-    sidePanel: true,
     presets: true,
     multiConvo: true,
     bookmarks: true,
@@ -1040,7 +1075,7 @@ export const configSchema = z.object({
     .optional(),
   interface: interfaceSchema,
   turnstile: turnstileSchema.optional(),
-  fileStrategy: fileSourceSchema.default(FileSources.local),
+  fileStrategy: fileStorageSchema.default(FileSources.local),
   fileStrategies: fileStrategiesSchema,
   actions: z
     .object({
@@ -1814,7 +1849,7 @@ export enum Constants {
   /** Key for the app's version. */
   VERSION = 'v0.8.4',
   /** Key for the Custom Config's version (librechat.yaml). */
-  CONFIG_VERSION = '1.3.6',
+  CONFIG_VERSION = '1.3.7',
   /** Standard value for the first message's `parentMessageId` value, to indicate no parent exists. */
   NO_PARENT = '00000000-0000-0000-0000-000000000000',
   /** Standard value to use whatever the submission prelim. `responseMessageId` is */
diff --git a/packages/data-provider/src/data-service.ts b/packages/data-provider/src/data-service.ts
index 6d1be48090..4cf2142149 100644
--- a/packages/data-provider/src/data-service.ts
+++ b/packages/data-provider/src/data-service.ts
@@ -866,6 +866,10 @@ export function getRandomPrompts(
 }
 
 /* Roles */
+export function listRoles(): Promise<q.ListRolesResponse> {
+  return request.get(`${endpoints.adminRoles()}?limit=200`);
+}
+
 export function getRole(roleName: string): Promise<r.TRole> {
   return request.get(endpoints.getRole(roleName));
 }
diff --git a/packages/data-provider/src/keys.ts b/packages/data-provider/src/keys.ts
index a5e67878ed..52208d3717 100644
--- a/packages/data-provider/src/keys.ts
+++ b/packages/data-provider/src/keys.ts
@@ -46,6 +46,7 @@ export enum QueryKeys {
   agentCategories = 'agentCategories',
   marketplaceAgents = 'marketplaceAgents',
   roles = 'roles',
+  rolesList = 'rolesList',
   conversationTags = 'conversationTags',
   health = 'health',
   userTerms = 'userTerms',
diff --git a/packages/data-provider/src/roles.ts b/packages/data-provider/src/roles.ts
index 1ba7a8cce2..0d81c55304 100644
--- a/packages/data-provider/src/roles.ts
+++ b/packages/data-provider/src/roles.ts
@@ -111,6 +111,16 @@ const defaultRolesSchema = z.object({
   }),
 });
 
+const systemRoleSet = new Set(Object.values(SystemRoles).map((r) => r.toUpperCase()));
+
+/** Case-insensitive check for reserved system role names. */
+export function isSystemRoleName(name: string | undefined | null): boolean {
+  if (!name) {
+    return false;
+  }
+  return systemRoleSet.has(name.toUpperCase());
+}
+
 export const roleDefaults = defaultRolesSchema.parse({
   [SystemRoles.ADMIN]: {
     name: SystemRoles.ADMIN,
diff --git a/packages/data-provider/src/types/queries.ts b/packages/data-provider/src/types/queries.ts
index ec0a70f9a8..980da52e8a 100644
--- a/packages/data-provider/src/types/queries.ts
+++ b/packages/data-provider/src/types/queries.ts
@@ -172,6 +172,13 @@ export type AccessRole = {
 
 export type AccessRolesResponse = AccessRole[];
 
+export type ListRolesResponse = {
+  roles: Array<{ _id?: string; name: string; description?: string }>;
+  total: number;
+  limit: number;
+  offset?: number;
+};
+
 export interface MCPServerStatus {
   requiresOAuth: boolean;
   connectionState: 'disconnected' | 'connecting' | 'connected' | 'error';
diff --git a/packages/data-schemas/package.json b/packages/data-schemas/package.json
index b257d73e59..ecb89f7e1e 100644
--- a/packages/data-schemas/package.json
+++ b/packages/data-schemas/package.json
@@ -55,7 +55,7 @@
     "@types/node": "^20.3.0",
     "jest": "^30.2.0",
     "jest-junit": "^16.0.0",
-    "mongodb-memory-server": "^10.1.4",
+    "mongodb-memory-server": "^11.0.1",
     "rimraf": "^6.1.3",
     "rollup": "^4.34.9",
     "rollup-plugin-peer-deps-external": "^2.2.4",
diff --git a/packages/data-schemas/src/app/interface.ts b/packages/data-schemas/src/app/interface.ts
index f07b3b8d4d..60ac929b53 100644
--- a/packages/data-schemas/src/app/interface.ts
+++ b/packages/data-schemas/src/app/interface.ts
@@ -29,14 +29,11 @@ export async function loadDefaultInterface({
 
   const loadedInterface: AppConfig['interfaceConfig'] = removeNullishValues({
     // UI elements - use schema defaults
-    endpointsMenu:
-      interfaceConfig?.endpointsMenu ?? (hasModelSpecs ? false : defaults.endpointsMenu),
     modelSelect:
       interfaceConfig?.modelSelect ??
       (hasModelSpecs ? includesAddedEndpoints : defaults.modelSelect),
     parameters: interfaceConfig?.parameters ?? (hasModelSpecs ? false : defaults.parameters),
     presets: interfaceConfig?.presets ?? (hasModelSpecs ? false : defaults.presets),
-    sidePanel: interfaceConfig?.sidePanel ?? defaults.sidePanel,
     privacyPolicy: interfaceConfig?.privacyPolicy ?? defaults.privacyPolicy,
     termsOfService: interfaceConfig?.termsOfService ?? defaults.termsOfService,
     mcpServers: interfaceConfig?.mcpServers ?? defaults.mcpServers,
diff --git a/packages/data-schemas/src/app/resolution.spec.ts b/packages/data-schemas/src/app/resolution.spec.ts
index 991f6afb40..e241b7f9a4 100644
--- a/packages/data-schemas/src/app/resolution.spec.ts
+++ b/packages/data-schemas/src/app/resolution.spec.ts
@@ -16,7 +16,7 @@ function fakeConfig(overrides: Record<string, unknown>, priority: number): IConf
 }
 
 const baseConfig = {
-  interfaceConfig: { endpointsMenu: true, sidePanel: true },
+  interfaceConfig: { modelSelect: true, parameters: true },
   registration: { enabled: true },
   endpoints: ['openAI'],
 } as unknown as AppConfig;
@@ -32,11 +32,11 @@ describe('mergeConfigOverrides', () => {
   });
 
   it('deep merges interface UI fields into interfaceConfig', () => {
-    const configs = [fakeConfig({ interface: { endpointsMenu: false } }, 10)];
+    const configs = [fakeConfig({ interface: { modelSelect: false } }, 10)];
     const result = mergeConfigOverrides(baseConfig, configs) as unknown as Record<string, unknown>;
     const iface = result.interfaceConfig as Record<string, unknown>;
-    expect(iface.endpointsMenu).toBe(false);
-    expect(iface.sidePanel).toBe(true);
+    expect(iface.modelSelect).toBe(false);
+    expect(iface.parameters).toBe(true);
   });
 
   it('sorts by priority — higher priority wins', () => {
@@ -58,16 +58,16 @@ describe('mergeConfigOverrides', () => {
 
   it('does not mutate the base config', () => {
     const original = JSON.parse(JSON.stringify(baseConfig));
-    const configs = [fakeConfig({ interface: { endpointsMenu: false } }, 10)];
+    const configs = [fakeConfig({ interface: { modelSelect: false } }, 10)];
     mergeConfigOverrides(baseConfig, configs);
     expect(baseConfig).toEqual(original);
   });
 
   it('handles null override values', () => {
-    const configs = [fakeConfig({ interface: { endpointsMenu: null } }, 10)];
+    const configs = [fakeConfig({ interface: { modelSelect: null } }, 10)];
     const result = mergeConfigOverrides(baseConfig, configs) as unknown as Record<string, unknown>;
     const iface = result.interfaceConfig as Record<string, unknown>;
-    expect(iface.endpointsMenu).toBeNull();
+    expect(iface.modelSelect).toBeNull();
   });
 
   it('skips configs with no overrides object', () => {
@@ -97,20 +97,20 @@ describe('mergeConfigOverrides', () => {
 
   it('merges three priority levels in order', () => {
     const configs = [
-      fakeConfig({ interface: { endpointsMenu: false } }, 0),
-      fakeConfig({ interface: { endpointsMenu: true, sidePanel: false } }, 10),
-      fakeConfig({ interface: { sidePanel: true } }, 100),
+      fakeConfig({ interface: { modelSelect: false } }, 0),
+      fakeConfig({ interface: { modelSelect: true, parameters: false } }, 10),
+      fakeConfig({ interface: { parameters: true } }, 100),
     ];
     const result = mergeConfigOverrides(baseConfig, configs) as unknown as Record<string, unknown>;
     const iface = result.interfaceConfig as Record<string, unknown>;
-    expect(iface.endpointsMenu).toBe(true);
-    expect(iface.sidePanel).toBe(true);
+    expect(iface.modelSelect).toBe(true);
+    expect(iface.parameters).toBe(true);
   });
 
   it('remaps all renamed YAML keys (exhaustiveness check)', () => {
     const base = {
       mcpConfig: null,
-      interfaceConfig: { endpointsMenu: true },
+      interfaceConfig: { modelSelect: true },
       turnstileConfig: {},
     } as unknown as AppConfig;
 
@@ -118,7 +118,7 @@ describe('mergeConfigOverrides', () => {
       fakeConfig(
         {
           mcpServers: { srv: { url: 'http://mcp' } },
-          interface: { endpointsMenu: false },
+          interface: { modelSelect: false },
           turnstile: { siteKey: 'key-123' },
         },
         10,
@@ -127,7 +127,7 @@ describe('mergeConfigOverrides', () => {
     const result = mergeConfigOverrides(base, configs) as unknown as Record<string, unknown>;
 
     expect(result.mcpConfig).toEqual({ srv: { url: 'http://mcp' } });
-    expect((result.interfaceConfig as Record<string, unknown>).endpointsMenu).toBe(false);
+    expect((result.interfaceConfig as Record<string, unknown>).modelSelect).toBe(false);
     expect((result.turnstileConfig as Record<string, unknown>).siteKey).toBe('key-123');
 
     expect(result.mcpServers).toBeUndefined();
@@ -137,14 +137,14 @@ describe('mergeConfigOverrides', () => {
 
   it('strips interface permission fields from overrides', () => {
     const base = {
-      interfaceConfig: { endpointsMenu: true, sidePanel: true },
+      interfaceConfig: { modelSelect: true, parameters: true },
     } as unknown as AppConfig;
 
     const configs = [
       fakeConfig(
         {
           interface: {
-            endpointsMenu: false,
+            modelSelect: false,
             prompts: false,
             agents: { use: false },
             marketplace: { use: false },
@@ -157,14 +157,14 @@ describe('mergeConfigOverrides', () => {
     const iface = result.interfaceConfig as Record<string, unknown>;
 
     // UI field should be merged
-    expect(iface.endpointsMenu).toBe(false);
+    expect(iface.modelSelect).toBe(false);
     // Boolean permission fields should be stripped
     expect(iface.prompts).toBeUndefined();
     // Object permission fields with only permission sub-keys should be stripped
     expect(iface.agents).toBeUndefined();
     expect(iface.marketplace).toBeUndefined();
     // Untouched base field preserved
-    expect(iface.sidePanel).toBe(true);
+    expect(iface.parameters).toBe(true);
   });
 
   it('preserves UI sub-keys in composite permission fields like mcpServers', () => {
@@ -220,7 +220,7 @@ describe('mergeConfigOverrides', () => {
 
   it('drops interface entirely when only permission fields are present', () => {
     const base = {
-      interfaceConfig: { endpointsMenu: true },
+      interfaceConfig: { modelSelect: true },
     } as unknown as AppConfig;
 
     const configs = [fakeConfig({ interface: { prompts: false, agents: false } }, 10)];
@@ -228,7 +228,7 @@ describe('mergeConfigOverrides', () => {
     const iface = result.interfaceConfig as Record<string, unknown>;
 
     // Base should be unchanged
-    expect(iface.endpointsMenu).toBe(true);
+    expect(iface.modelSelect).toBe(true);
     expect(iface.prompts).toBeUndefined();
     expect(iface.agents).toBeUndefined();
   });
@@ -281,7 +281,7 @@ describe('INTERFACE_PERMISSION_FIELDS', () => {
   });
 
   it('does not contain UI-only fields', () => {
-    const uiFields = ['endpointsMenu', 'modelSelect', 'parameters', 'presets', 'sidePanel'];
+    const uiFields = ['modelSelect', 'parameters', 'presets'];
     for (const field of uiFields) {
       expect(INTERFACE_PERMISSION_FIELDS.has(field)).toBe(false);
     }
diff --git a/packages/data-schemas/src/methods/config.spec.ts b/packages/data-schemas/src/methods/config.spec.ts
index 8bcf73a733..8ab6be35ee 100644
--- a/packages/data-schemas/src/methods/config.spec.ts
+++ b/packages/data-schemas/src/methods/config.spec.ts
@@ -32,7 +32,7 @@ describe('upsertConfig', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: false } },
+      { interface: { modelSelect: false } },
       10,
     );
 
@@ -49,7 +49,7 @@ describe('upsertConfig', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: false } },
+      { interface: { modelSelect: false } },
       10,
     );
 
@@ -57,7 +57,7 @@ describe('upsertConfig', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: true } },
+      { interface: { modelSelect: true } },
       10,
     );
 
@@ -70,7 +70,7 @@ describe('upsertConfig', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: true } },
+      { interface: { modelSelect: true } },
       10,
     );
 
@@ -78,7 +78,7 @@ describe('upsertConfig', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: false } },
+      { interface: { modelSelect: false } },
       10,
     );
 
@@ -240,7 +240,7 @@ describe('patchConfigFields', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: true, sidePanel: true } },
+      { interface: { modelSelect: true, parameters: true } },
       10,
     );
 
@@ -248,14 +248,14 @@ describe('patchConfigFields', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { 'interface.endpointsMenu': false },
+      { 'interface.modelSelect': false },
       10,
     );
 
     const overrides = result!.overrides as Record<string, unknown>;
     const iface = overrides.interface as Record<string, unknown>;
-    expect(iface.endpointsMenu).toBe(false);
-    expect(iface.sidePanel).toBe(true);
+    expect(iface.modelSelect).toBe(false);
+    expect(iface.parameters).toBe(true);
   });
 
   it('creates a config if none exists (upsert)', async () => {
@@ -263,7 +263,7 @@ describe('patchConfigFields', () => {
       PrincipalType.ROLE,
       'newrole',
       PrincipalModel.ROLE,
-      { 'interface.endpointsMenu': false },
+      { 'interface.modelSelect': false },
       10,
     );
 
@@ -278,19 +278,19 @@ describe('unsetConfigField', () => {
       PrincipalType.ROLE,
       'admin',
       PrincipalModel.ROLE,
-      { interface: { endpointsMenu: false, sidePanel: false } },
+      { interface: { modelSelect: false, parameters: false } },
       10,
     );
 
     const result = await methods.unsetConfigField(
       PrincipalType.ROLE,
       'admin',
-      'interface.endpointsMenu',
+      'interface.modelSelect',
     );
     const overrides = result!.overrides as Record<string, unknown>;
     const iface = overrides.interface as Record<string, unknown>;
-    expect(iface.endpointsMenu).toBeUndefined();
-    expect(iface.sidePanel).toBe(false);
+    expect(iface.modelSelect).toBeUndefined();
+    expect(iface.parameters).toBe(false);
   });
 
   it('returns null for non-existent config', async () => {
diff --git a/packages/data-schemas/src/methods/convoStructure.spec.ts b/packages/data-schemas/src/methods/convoStructure.spec.ts
index 77a9913233..6ec2cf8c0e 100644
--- a/packages/data-schemas/src/methods/convoStructure.spec.ts
+++ b/packages/data-schemas/src/methods/convoStructure.spec.ts
@@ -116,11 +116,11 @@ describe('Conversation Structure Tests', () => {
       conversationId,
       user: userId,
       text: `Message ${i}`,
-      createdAt: new Date(Date.now() + (i % 2 === 0 ? i * 500000 : -i * 500000)),
+      createdAt: new Date(Date.now() + i * 1000),
     }));
 
-    // Save messages with new timestamps being generated (message objects ignored)
-    await bulkSaveMessages(messages);
+    // Save messages preserving original timestamps so sort order is deterministic
+    await bulkSaveMessages(messages, true);
 
     // Retrieve messages (this will sort by createdAt, but it shouldn't matter now)
     const retrievedMessages = await getMessages({ conversationId, user: userId });
diff --git a/packages/data-schemas/src/models/plugins/mongoMeili.spec.ts b/packages/data-schemas/src/models/plugins/mongoMeili.spec.ts
index b1d3e24129..1d341a7939 100644
--- a/packages/data-schemas/src/models/plugins/mongoMeili.spec.ts
+++ b/packages/data-schemas/src/models/plugins/mongoMeili.spec.ts
@@ -73,7 +73,10 @@ describe('Meilisearch Mongoose plugin', () => {
       title: 'Test Conversation',
       endpoint: EModelEndpoint.openAI,
     });
-    expect(mockAddDocuments).toHaveBeenCalled();
+    expect(mockAddDocuments).toHaveBeenCalledWith(
+      [expect.objectContaining({ conversationId: expect.anything() })],
+      { primaryKey: 'conversationId' },
+    );
   });
 
   test('saving conversation indexes with expiredAt=null w/ meilisearch', async () => {
@@ -105,7 +108,10 @@ describe('Meilisearch Mongoose plugin', () => {
       user: new mongoose.Types.ObjectId(),
       isCreatedByUser: true,
     });
-    expect(mockAddDocuments).toHaveBeenCalled();
+    expect(mockAddDocuments).toHaveBeenCalledWith(
+      [expect.objectContaining({ messageId: expect.anything() })],
+      { primaryKey: 'messageId' },
+    );
   });
 
   test('saving messages with expiredAt=null indexes w/ meilisearch', async () => {
@@ -130,6 +136,87 @@ describe('Meilisearch Mongoose plugin', () => {
     expect(mockAddDocuments).not.toHaveBeenCalled();
   });
 
+  test('updating an indexed conversation calls updateDocuments with primaryKey', async () => {
+    const conversationModel = createConversationModel(mongoose);
+    const convo = await conversationModel.create({
+      conversationId: new mongoose.Types.ObjectId().toString(),
+      user: new mongoose.Types.ObjectId(),
+      title: 'Original Title',
+      endpoint: EModelEndpoint.openAI,
+    });
+    mockUpdateDocuments.mockClear();
+
+    convo._meiliIndex = true;
+    convo.title = 'Updated Title';
+    await convo.save();
+
+    expect(mockUpdateDocuments).toHaveBeenCalledWith(
+      [expect.objectContaining({ conversationId: expect.anything() })],
+      { primaryKey: 'conversationId' },
+    );
+  });
+
+  test('updating an indexed message calls updateDocuments with primaryKey: messageId', async () => {
+    const messageModel = createMessageModel(mongoose);
+    const msg = await messageModel.create({
+      messageId: new mongoose.Types.ObjectId().toString(),
+      conversationId: new mongoose.Types.ObjectId(),
+      user: new mongoose.Types.ObjectId(),
+      isCreatedByUser: true,
+    });
+    mockUpdateDocuments.mockClear();
+
+    msg._meiliIndex = true;
+    msg.text = 'Updated text';
+    await msg.save();
+
+    expect(mockUpdateDocuments).toHaveBeenCalledWith(
+      [expect.objectContaining({ messageId: expect.anything() })],
+      { primaryKey: 'messageId' },
+    );
+  });
+
+  test('deleteObjectFromMeili calls deleteDocument with messageId, not _id', async () => {
+    const messageModel = createMessageModel(mongoose);
+    const msgId = new mongoose.Types.ObjectId().toString();
+    const msg = await messageModel.create({
+      messageId: msgId,
+      conversationId: new mongoose.Types.ObjectId(),
+      user: new mongoose.Types.ObjectId(),
+      isCreatedByUser: true,
+    });
+    mockDeleteDocument.mockClear();
+
+    const typedMsg = msg as unknown as import('./mongoMeili').DocumentWithMeiliIndex;
+    await new Promise<void>((resolve, reject) => {
+      typedMsg.deleteObjectFromMeili!((err) => (err ? reject(err) : resolve()));
+    });
+
+    expect(mockDeleteDocument).toHaveBeenCalledWith(msgId);
+    expect(mockDeleteDocument).not.toHaveBeenCalledWith(String(msg._id));
+  });
+
+  test('updateDocuments receives preprocessed data with primaryKey', async () => {
+    const conversationModel = createConversationModel(mongoose);
+    const conversationId = 'abc|def|ghi';
+    const convo = await conversationModel.create({
+      conversationId,
+      user: new mongoose.Types.ObjectId(),
+      title: 'Pipe Test',
+      endpoint: EModelEndpoint.openAI,
+    });
+    mockUpdateDocuments.mockClear();
+
+    convo._meiliIndex = true;
+    convo.title = 'Updated Pipe Test';
+    await convo.save();
+
+    expect(mockUpdateDocuments).toHaveBeenCalledWith(
+      [expect.objectContaining({ conversationId: 'abc--def--ghi' })],
+      { primaryKey: 'conversationId' },
+    );
+  });
+
   test('sync w/ meili does not include TTL documents', async () => {
     const conversationModel = createConversationModel(mongoose) as SchemaWithMeiliMethods;
     await conversationModel.create({
@@ -299,8 +386,10 @@ describe('Meilisearch Mongoose plugin', () => {
       // Run sync which should call processSyncBatch internally
       await conversationModel.syncWithMeili();
 
-      // Verify addDocumentsInBatches was called (new batch method)
-      expect(mockAddDocumentsInBatches).toHaveBeenCalled();
+      // Verify addDocumentsInBatches was called with explicit primaryKey
+      expect(mockAddDocumentsInBatches).toHaveBeenCalledWith(expect.any(Array), undefined, {
+        primaryKey: 'conversationId',
+      });
     });
 
     test('addObjectToMeili retries on failure', async () => {
diff --git a/packages/data-schemas/src/models/plugins/mongoMeili.ts b/packages/data-schemas/src/models/plugins/mongoMeili.ts
index cc01dbb6c7..125e7bab71 100644
--- a/packages/data-schemas/src/models/plugins/mongoMeili.ts
+++ b/packages/data-schemas/src/models/plugins/mongoMeili.ts
@@ -94,7 +94,7 @@ const getSyncConfig = () => ({
  * Validates the required options for configuring the mongoMeili plugin.
  */
 const validateOptions = (options: Partial<MongoMeiliOptions>): void => {
-  const requiredKeys: (keyof MongoMeiliOptions)[] = ['host', 'apiKey', 'indexName'];
+  const requiredKeys: (keyof MongoMeiliOptions)[] = ['host', 'apiKey', 'indexName', 'primaryKey'];
   requiredKeys.forEach((key) => {
     if (!options[key]) {
       throw new Error(`Missing mongoMeili Option: ${key}`);
@@ -130,19 +130,21 @@ const processBatch = async <T>(
  * @param config - Configuration object.
  * @param config.index - The MeiliSearch index object.
  * @param config.attributesToIndex - List of attributes to index.
+ * @param config.primaryKey - The primary key field for MeiliSearch document operations.
  * @param config.syncOptions - Sync configuration options.
  * @returns A class definition that will be loaded into the Mongoose schema.
  */
 const createMeiliMongooseModel = ({
   index,
   attributesToIndex,
+  primaryKey,
   syncOptions,
 }: {
   index: Index<MeiliIndexable>;
   attributesToIndex: string[];
+  primaryKey: string;
   syncOptions: { batchSize: number; delayMs: number };
 }) => {
-  const primaryKey = attributesToIndex[0];
   const syncConfig = { ...getSyncConfig(), ...syncOptions };
 
   class MeiliMongooseModel {
@@ -255,7 +257,7 @@ const createMeiliMongooseModel = ({
 
       try {
         // Add documents to MeiliSearch
-        await index.addDocumentsInBatches(formattedDocs);
+        await index.addDocumentsInBatches(formattedDocs, undefined, { primaryKey });
 
         // Update MongoDB to mark documents as indexed.
         // { timestamps: false } prevents Mongoose from touching updatedAt, preserving
@@ -422,7 +424,7 @@ const createMeiliMongooseModel = ({
 
       while (retryCount < maxRetries) {
         try {
-          await index.addDocuments([object]);
+          await index.addDocuments([object], { primaryKey });
           break;
         } catch (error) {
           retryCount++;
@@ -436,7 +438,8 @@ const createMeiliMongooseModel = ({
       }
 
       try {
-        await this.collection.updateMany(
+        // eslint-disable-next-line no-restricted-syntax -- _meiliIndex is an internal bookkeeping flag, not tenant-scoped data
+        await this.collection.updateOne(
           { _id: this._id as Types.ObjectId },
           { $set: { _meiliIndex: true } },
         );
@@ -456,10 +459,8 @@ const createMeiliMongooseModel = ({
       next: CallbackWithoutResultAndOptionalError,
     ): Promise<void> {
       try {
-        const object = _.omitBy(_.pick(this.toJSON(), attributesToIndex), (v, k) =>
-          k.startsWith('$'),
-        );
-        await index.updateDocuments([object]);
+        const object = this.preprocessObjectForIndex!();
+        await index.updateDocuments([object], { primaryKey });
         next();
       } catch (error) {
         logger.error('[updateObjectToMeili] Error updating document in Meili:', error);
@@ -477,7 +478,7 @@ const createMeiliMongooseModel = ({
       next: CallbackWithoutResultAndOptionalError,
     ): Promise<void> {
       try {
-        await index.deleteDocument(this._id as string);
+        await index.deleteDocument(String(this[primaryKey as keyof DocumentWithMeiliIndex]));
         next();
       } catch (error) {
         logger.error('[deleteObjectFromMeili] Error deleting document from Meili:', error);
@@ -643,7 +644,7 @@ export default function mongoMeili(schema: Schema, options: MongoMeiliOptions):
     logger.debug(`[mongoMeili] Added 'user' field to ${indexName} index attributes`);
   }
 
-  schema.loadClass(createMeiliMongooseModel({ index, attributesToIndex, syncOptions }));
+  schema.loadClass(createMeiliMongooseModel({ index, attributesToIndex, primaryKey, syncOptions }));
 
   // Register Mongoose hooks
   schema.post('save', function (doc: DocumentWithMeiliIndex, next) {
diff --git a/packages/data-schemas/src/types/app.ts b/packages/data-schemas/src/types/app.ts
index 73d65611b0..5118fa9583 100644
--- a/packages/data-schemas/src/types/app.ts
+++ b/packages/data-schemas/src/types/app.ts
@@ -1,6 +1,6 @@
 import type {
   TEndpoint,
-  FileSources,
+  FileStorage,
   TFileConfig,
   TAzureConfig,
   TCustomConfig,
@@ -62,7 +62,7 @@ export interface AppConfig {
   /** Web search configuration */
   webSearch?: TCustomConfig['webSearch'];
   /** File storage strategy ('local', 's3', 'firebase', 'azure_blob') */
-  fileStrategy: FileSources.local | FileSources.s3 | FileSources.firebase | FileSources.azure_blob;
+  fileStrategy: FileStorage;
   /** File strategies configuration */
   fileStrategies?: TCustomConfig['fileStrategies'];
   /** Registration configurations */