🎯 refactor: Centralize Agent Model Handling Across Conversation Lifecycle (#10956)

* refactor: Implement clearModelForNonEphemeralAgent utility for improved agent handling

- Introduced clearModelForNonEphemeralAgent function to manage model state for non-ephemeral agents across various components.
- Updated ModelSelectorContext to initialize model based on agent type.
- Enhanced useNavigateToConvo, useQueryParams, and useSelectMention hooks to clear model for non-ephemeral agents.
- Refactored buildDefaultConvo and endpoints utility to ensure proper handling of agent_id and model state.
- Improved overall conversation logic and state management for better performance and reliability.

* refactor: Enhance useNewConvo hook to improve agent conversation handling

- Added logic to skip access checks for existing agent conversations, utilizing localStorage to restore conversations after refresh.
- Improved handling of default endpoints for agents based on user access and existing conversation state, ensuring more reliable conversation initialization.

* refactor: Update ChatRoute and useAuthRedirect to include user roles

- Enhanced ChatRoute to utilize user roles for improved conversation state management.
- Modified useAuthRedirect to return user roles alongside authentication status, ensuring roles are available for conditional logic in ChatRoute.
- Adjusted conversation initialization logic to depend on the loaded roles, enhancing the reliability of the conversation setup.

* refactor: Update BaseClient to handle non-ephemeral agents in conversation logic

- Added a check for non-ephemeral agents in BaseClient, modifying the exceptions set to include 'model' when applicable.
- Enhanced conversation handling to improve flexibility based on agent type.

* test: Add mock for clearModelForNonEphemeralAgent in useQueryParams tests

- Introduced a mock for clearModelForNonEphemeralAgent to enhance testing of query parameters related to non-ephemeral agents.
- This addition supports improved test coverage and ensures proper handling of model state in relevant scenarios.

* refactor: Simplify mocks in useQueryParams tests for improved clarity

- Updated the mocking strategy for utilities in useQueryParams tests to use actual implementations where possible, while still suppressing test output for the logger.
- Enhanced the mock for tQueryParamsSchema to minimize complexity and avoid unnecessary validation during tests, improving test reliability and maintainability.

* refactor: Enhance agent identification logic in BaseClient for improved clarity

* chore: Import Constants in families.ts for enhanced functionality

client/src/utils/buildDefaultConvo.ts

@@ -1,10 +1,12 @@
 import {
+  Constants,
   parseConvo,
   EModelEndpoint,
   isAssistantsEndpoint,
   isAgentsEndpoint,
 } from 'librechat-data-provider';
 import type { TConversation, EndpointSchemaKey } from 'librechat-data-provider';
+import { clearModelForNonEphemeralAgent } from './endpoints';
 import { getLocalStorageItems } from './localStorage';
 
 const buildDefaultConvo = ({
@@ -66,10 +68,17 @@ const buildDefaultConvo = ({
   // Ensures agent_id is always defined
   const agentId = convo?.agent_id ?? '';
   const defaultAgentId = lastConversationSetup?.agent_id ?? '';
-  if (isAgentsEndpoint(endpoint) && !defaultAgentId && agentId) {
+  if (
+    isAgentsEndpoint(endpoint) &&
+    agentId &&
+    (!defaultAgentId || defaultAgentId === Constants.EPHEMERAL_AGENT_ID)
+  ) {
     defaultConvo.agent_id = agentId;
   }
 
+  // Clear model for non-ephemeral agents - agents use their configured model internally
+  clearModelForNonEphemeralAgent(defaultConvo);
+
   defaultConvo.tools = lastConversationSetup?.tools ?? lastSelectedTools ?? defaultConvo.tools;
 
   return defaultConvo;

client/src/utils/endpoints.ts

@@ -11,6 +11,27 @@ import {
 import type * as t from 'librechat-data-provider';
 import type { LocalizeFunction, IconsRecord } from '~/common';
 
+/**
+ * Clears model for non-ephemeral agent conversations.
+ * Agents use their configured model internally, so the conversation model should be undefined.
+ * Mutates the template in place.
+ */
+export function clearModelForNonEphemeralAgent<
+  T extends {
+    endpoint?: EModelEndpoint | string | null;
+    agent_id?: string | null;
+    model?: string | null;
+  },
+>(template: T): void {
+  if (
+    isAgentsEndpoint(template.endpoint) &&
+    template.agent_id &&
+    template.agent_id !== Constants.EPHEMERAL_AGENT_ID
+  ) {
+    template.model = undefined as T['model'];
+  }
+}
+
 export const getEntityName = ({
   name = '',
   localize,
@@ -125,6 +146,18 @@ export function getConvoSwitchLogic(params: ConversationInitParams): InitiatedTe
     conversationId: 'new',
   };
 
+  // Reset agent_id if switching to a non-agents endpoint but template has a non-ephemeral agent_id
+  if (
+    !isAgentsEndpoint(newEndpoint) &&
+    template.agent_id &&
+    template.agent_id !== Constants.EPHEMERAL_AGENT_ID
+  ) {
+    template.agent_id = Constants.EPHEMERAL_AGENT_ID;
+  }
+
+  // Clear model for non-ephemeral agents - agents use their configured model internally
+  clearModelForNonEphemeralAgent(template);
+
   const isAssistantSwitch =
     isAssistantsEndpoint(newEndpoint) &&
     isAssistantsEndpoint(currentEndpoint) &&