Allow AI model switching based on User Tier (#1151)

Overview
---
Enable free tier users to chat with any AI model made available on free tier 
of production deployments like [Khoj cloud](https://app.khoj.dev).

Previously model switching was completely disabled for users on free tier.

Details
---
- Track price tier of each Chat, Speech, Image, Voice AI model in DB
- Update API to allow free tier users to switch between free models
- Update web app to allow model switching on agent creation, settings
  chat page (via right side pane), even for free tier users.

.github/workflows/pypi.yml

@@ -49,7 +49,7 @@ jobs:
       - name: 📂 Copy Generated Files
         run: |
           mkdir -p src/khoj/interface/compiled
-          cp -r /opt/hostedtoolcache/Python/3.11.11/x64/lib/python3.11/site-packages/khoj/interface/compiled/* src/khoj/interface/compiled/
+          cp -r /opt/hostedtoolcache/Python/3.11.12/x64/lib/python3.11/site-packages/khoj/interface/compiled/* src/khoj/interface/compiled/
 
       - name: ⚙️ Build Python Package
         run: |

src/interface/web/app/chat/page.tsx

@@ -24,9 +24,7 @@ import {
     ChatOptions,
 } from "../components/chatInputArea/chatInputArea";
 import { useAuthenticatedData } from "../common/auth";
-import {
+import { AgentData } from "@/app/components/agentCard/agentCard";
-    AgentData,
-} from "@/app/components/agentCard/agentCard";
 import { ChatSessionActionMenu } from "../components/allConversations/allConversations";
 import { SidebarInset, SidebarProvider, SidebarTrigger } from "@/components/ui/sidebar";
 import { AppSidebar } from "../components/appSidebar/appSidebar";
@@ -50,6 +48,7 @@ interface ChatBodyDataProps {
     setTriggeredAbort: (triggeredAbort: boolean) => void;
     isChatSideBarOpen: boolean;
     setIsChatSideBarOpen: (open: boolean) => void;
+    isActive?: boolean;
 }
 
 function ChatBodyData(props: ChatBodyDataProps) {
@@ -180,9 +179,11 @@ function ChatBodyData(props: ChatBodyDataProps) {
             </div>
             <ChatSidebar
                 conversationId={conversationId}
+                isActive={props.isActive}
                 isOpen={props.isChatSideBarOpen}
                 onOpenChange={props.setIsChatSideBarOpen}
-                isMobileWidth={props.isMobileWidth} />
+                isMobileWidth={props.isMobileWidth}
+            />
         </div>
     );
 }
@@ -480,12 +481,13 @@ export default function Chat() {
                                     setTriggeredAbort={setTriggeredAbort}
                                     isChatSideBarOpen={isChatSideBarOpen}
                                     setIsChatSideBarOpen={setIsChatSideBarOpen}
+                                    isActive={authenticatedData?.is_active}
                                 />
                             </Suspense>
                         </div>
                     </div>
                 </div>
             </SidebarInset>
-        </SidebarProvider >
+        </SidebarProvider>
     );
 }

src/interface/web/app/common/auth.ts

@@ -33,6 +33,7 @@ export function useAuthenticatedData() {
 export interface ModelOptions {
     id: number;
     name: string;
+    tier: string;
     description: string;
     strengths: string;
 }

src/interface/web/app/common/modelSelector.tsx

@@ -30,6 +30,7 @@ import { Skeleton } from "@/components/ui/skeleton";
 interface ModelSelectorProps extends PopoverProps {
     onSelect: (model: ModelOptions) => void;
     disabled?: boolean;
+    isActive?: boolean;
     initialModel?: string;
 }
 
@@ -116,6 +117,7 @@ export function ModelSelector({ ...props }: ModelSelectorProps) {
                                                             setSelectedModel(model)
                                                             setOpen(false)
                                                         }}
+                                                        isActive={props.isActive}
                                                     />
                                                 ))}
                                         </CommandGroup>
@@ -165,6 +167,7 @@ export function ModelSelector({ ...props }: ModelSelectorProps) {
                                                                 setSelectedModel(model)
                                                                 setOpen(false)
                                                             }}
+                                                            isActive={props.isActive}
                                                         />
                                                     ))}
                                             </CommandGroup>
@@ -184,9 +187,10 @@ interface ModelItemProps {
     isSelected: boolean,
     onSelect: () => void,
     onPeek: (model: ModelOptions) => void
+    isActive?: boolean
 }
 
-function ModelItem({ model, isSelected, onSelect, onPeek }: ModelItemProps) {
+function ModelItem({ model, isSelected, onSelect, onPeek, isActive }: ModelItemProps) {
     const ref = React.useRef<HTMLDivElement>(null)
 
     useMutationObserver(ref, (mutations) => {
@@ -207,8 +211,9 @@ function ModelItem({ model, isSelected, onSelect, onPeek }: ModelItemProps) {
             onSelect={onSelect}
             ref={ref}
             className="data-[selected=true]:bg-muted data-[selected=true]:text-secondary-foreground"
+            disabled={!isActive && model.tier !== "free"}
         >
-            {model.name}
+            {model.name} {model.tier === "standard" && <span className="text-green-500 ml-2">(Futurist)</span>}
             <Check
                 className={cn("ml-auto", isSelected ? "opacity-100" : "opacity-0")}
             />

src/interface/web/app/components/agentCard/agentCard.tsx

@@ -773,11 +773,7 @@ export function AgentModificationForm(props: AgentModificationFormProps) {
                                         <p>Which chat model would you like to use?</p>
                                     )}
                                 </FormDescription>
-                                <Select
+                                <Select onValueChange={field.onChange} defaultValue={field.value}>
-                                    onValueChange={field.onChange}
-                                    defaultValue={field.value}
-                                    disabled={!props.isSubscribed}
-                                >
                                     <FormControl>
                                         <SelectTrigger className="text-left dark:bg-muted">
                                             <SelectValue />
@@ -788,9 +784,18 @@ export function AgentModificationForm(props: AgentModificationFormProps) {
                                             <SelectItem
                                                 key={modelOption.id}
                                                 value={modelOption.name}
+                                                disabled={
+                                                    !props.isSubscribed &&
+                                                    modelOption.tier !== "free"
+                                                }
                                             >
                                                 <div className="flex items-center space-x-2">
-                                                    {modelOption.name}
+                                                    {modelOption.name}{" "}
+                                                    {modelOption.tier === "standard" && (
+                                                        <span className="text-green-500 ml-2">
+                                                            (Futurist)
+                                                        </span>
+                                                    )}
                                                 </div>
                                             </SelectItem>
                                         ))}

src/interface/web/app/components/chatSidebar/chatSidebar.tsx

@@ -34,6 +34,7 @@ interface ChatSideBarProps {
     isOpen: boolean;
     isMobileWidth?: boolean;
     onOpenChange: (open: boolean) => void;
+    isActive?: boolean;
 }
 
 const fetcher = (url: string) => fetch(url).then((res) => res.json());
@@ -527,9 +528,10 @@ function ChatSidebarInternal({ ...props }: ChatSideBarProps) {
                                 <SidebarMenu className="p-0 m-0">
                                     <SidebarMenuItem key={"model"} className="list-none">
                                         <ModelSelector
-                                            disabled={!isEditable || !isSubscribed}
+                                            disabled={!isEditable}
                                             onSelect={(model) => handleModelSelect(model.name)}
                                             initialModel={isDefaultAgent ? undefined : agentData?.chat_model}
+                                            isActive={props.isActive}
                                         />
                                     </SidebarMenuItem>
                                 </SidebarMenu>

src/interface/web/app/settings/page.tsx

@@ -77,10 +77,11 @@ import { saveAs } from 'file-saver';
 interface DropdownComponentProps {
     items: ModelOptions[];
     selected: number;
+    isActive?: boolean;
     callbackFunc: (value: string) => Promise<void>;
 }
 
-const DropdownComponent: React.FC<DropdownComponentProps> = ({ items, selected, callbackFunc }) => {
+const DropdownComponent: React.FC<DropdownComponentProps> = ({ items, selected, isActive, callbackFunc }) => {
     const [position, setPosition] = useState(selected?.toString() ?? "0");
 
     return (
@@ -111,8 +112,9 @@ const DropdownComponent: React.FC<DropdownComponentProps> = ({ items, selected,
                                 <DropdownMenuRadioItem
                                     key={item.id.toString()}
                                     value={item.id.toString()}
+                                    disabled={!isActive && item.tier !== "free"}
                                 >
-                                    {item.name}
+                                    {item.name} {item.tier === "standard" && <span className="text-green-500 ml-2">(Futurist)</span>}
                                 </DropdownMenuRadioItem>
                             ))}
                         </DropdownMenuRadioGroup>
@@ -520,33 +522,44 @@ export default function SettingsView() {
         }
     };
 
-    const updateModel = (name: string) => async (id: string) => {
+    const updateModel = (modelType: string) => async (id: string) => {
-        if (!userConfig?.is_active) {
+        // Get the selected model from the options
+        const modelOptions = modelType === "chat"
+            ? userConfig?.chat_model_options
+            : modelType === "paint"
+                ? userConfig?.paint_model_options
+                : userConfig?.voice_model_options;
+
+        const selectedModel = modelOptions?.find(model => model.id.toString() === id);
+        const modelName = selectedModel?.name;
+
+        // Check if the model is free tier or if the user is active
+        if (!userConfig?.is_active && selectedModel?.tier !== "free") {
             toast({
                 title: `Model Update`,
-                description: `You need to be subscribed to update ${name} models`,
+                description: `Subscribe to switch ${modelType} model to ${modelName}.`,
                 variant: "destructive",
             });
             return;
         }
 
         try {
-            const response = await fetch(`/api/model/${name}?id=` + id, {
+            const response = await fetch(`/api/model/${modelType}?id=` + id, {
                 method: "POST",
                 headers: {
                     "Content-Type": "application/json",
                 },
             });
 
-            if (!response.ok) throw new Error("Failed to update model");
+            if (!response.ok) throw new Error(`Failed to switch ${modelType} model to ${modelName}`);
 
             toast({
-                title: `✅ Updated ${toTitleCase(name)} Model`,
+                title: `✅ Switched ${modelType} model to ${modelName}`,
             });
         } catch (error) {
-            console.error(`Failed to update ${name} model:`, error);
+            console.error(`Failed to update ${modelType} model to ${modelName}:`, error);
             toast({
-                description: `❌ Failed to update ${toTitleCase(name)} model. Try again.`,
+                description: `❌ Failed to switch ${modelType} model to ${modelName}. Try again.`,
                 variant: "destructive",
             });
         }
@@ -1103,13 +1116,16 @@ export default function SettingsView() {
                                                             selected={
                                                                 userConfig.selected_chat_model_config
                                                             }
+                                                            isActive={userConfig.is_active}
                                                             callbackFunc={updateModel("chat")}
                                                         />
                                                     </CardContent>
                                                     <CardFooter className="flex flex-wrap gap-4">
                                                         {!userConfig.is_active && (
                                                             <p className="text-gray-400">
-                                                                Subscribe to switch model
+                                                                {userConfig.chat_model_options.some(model => model.tier === "free")
+                                                                    ? "Free models available"
+                                                                    : "Subscribe to switch model"}
                                                             </p>
                                                         )}
                                                     </CardFooter>
@@ -1131,13 +1147,16 @@ export default function SettingsView() {
                                                             selected={
                                                                 userConfig.selected_paint_model_config
                                                             }
+                                                            isActive={userConfig.is_active}
                                                             callbackFunc={updateModel("paint")}
                                                         />
                                                     </CardContent>
                                                     <CardFooter className="flex flex-wrap gap-4">
                                                         {!userConfig.is_active && (
                                                             <p className="text-gray-400">
-                                                                Subscribe to switch model
+                                                                {userConfig.paint_model_options.some(model => model.tier === "free")
+                                                                    ? "Free models available"
+                                                                    : "Subscribe to switch model"}
                                                             </p>
                                                         )}
                                                     </CardFooter>
@@ -1159,13 +1178,16 @@ export default function SettingsView() {
                                                             selected={
                                                                 userConfig.selected_voice_model_config
                                                             }
+                                                            isActive={userConfig.is_active}
                                                             callbackFunc={updateModel("voice")}
                                                         />
                                                     </CardContent>
                                                     <CardFooter className="flex flex-wrap gap-4">
                                                         {!userConfig.is_active && (
                                                             <p className="text-gray-400">
-                                                                Subscribe to switch model
+                                                                {userConfig.voice_model_options.some(model => model.tier === "free")
+                                                                    ? "Free models available"
+                                                                    : "Subscribe to switch model"}
                                                             </p>
                                                         )}
                                                     </CardFooter>

src/interface/web/package.json

@@ -11,7 +11,7 @@
         "cicollectstatic": "bash -c 'pushd ../../../ && python3 src/khoj/manage.py collectstatic --noinput && popd'",
         "export": "yarn build && cp -r out/ ../../khoj/interface/built && yarn collectstatic",
         "ciexport": "yarn build && cp -r out/ ../../khoj/interface/built && yarn cicollectstatic",
-        "pypiciexport": "yarn build && cp -r out/ /opt/hostedtoolcache/Python/3.11.11/x64/lib/python3.11/site-packages/khoj/interface/compiled && yarn cicollectstatic",
+        "pypiciexport": "yarn build && cp -r out/ /opt/hostedtoolcache/Python/3.11.12/x64/lib/python3.11/site-packages/khoj/interface/compiled && yarn cicollectstatic",
         "watch": "nodemon --watch . --ext js,jsx,ts,tsx,css --ignore 'out/**/*' --exec 'yarn export'",
         "windowswatch": "nodemon --watch . --ext js,jsx,ts,tsx,css --ignore 'out/**/*' --exec 'yarn windowsexport'",
         "windowscollectstatic": "cd ..\\..\\.. && .\\.venv\\Scripts\\Activate.bat && py .\\src\\khoj\\manage.py collectstatic --noinput && .\\.venv\\Scripts\\deactivate.bat && cd ..",

src/khoj/database/adapters/__init__.py

@@ -48,6 +48,7 @@ from khoj.database.models import (
     KhojApiUser,
     KhojUser,
     NotionConfig,
+    PriceTier,
     ProcessLock,
     PublicConversation,
     RateLimitRecord,
@@ -1153,22 +1154,36 @@ class ConversationAdapters:
     @staticmethod
     def get_chat_model(user: KhojUser):
         subscribed = is_user_subscribed(user)
-        if not subscribed:
-            return ConversationAdapters.get_default_chat_model(user)
         config = UserConversationConfig.objects.filter(user=user).first()
+        if subscribed:
+            # Subscibed users can use any available chat model
             if config:
                 return config.setting
+            # Fallback to the default advanced chat model
             return ConversationAdapters.get_advanced_chat_model(user)
+        else:
+            # Non-subscribed users can use any free chat model
+            if config and config.setting.price_tier == PriceTier.FREE:
+                return config.setting
+            # Fallback to the default chat model
+            return ConversationAdapters.get_default_chat_model(user)
 
     @staticmethod
     async def aget_chat_model(user: KhojUser):
         subscribed = await ais_user_subscribed(user)
-        if not subscribed:
-            return await ConversationAdapters.aget_default_chat_model(user)
         config = await UserConversationConfig.objects.filter(user=user).prefetch_related("setting").afirst()
+        if subscribed:
+            # Subscibed users can use any available chat model
             if config:
                 return config.setting
-        return ConversationAdapters.aget_advanced_chat_model(user)
+            # Fallback to the default advanced chat model
+            return await ConversationAdapters.aget_advanced_chat_model(user)
+        else:
+            # Non-subscribed users can use any free chat model
+            if config and config.setting.price_tier == PriceTier.FREE:
+                return config.setting
+            # Fallback to the default chat model
+            return await ConversationAdapters.aget_default_chat_model(user)
 
     @staticmethod
     def get_chat_model_by_name(chat_model_name: str, ai_model_api_name: str = None):
@@ -1176,6 +1191,12 @@ class ConversationAdapters:
             return ChatModel.objects.filter(name=chat_model_name, ai_model_api__name=ai_model_api_name).first()
         return ChatModel.objects.filter(name=chat_model_name).first()
 
+    @staticmethod
+    async def aget_chat_model_by_name(chat_model_name: str, ai_model_api_name: str = None):
+        if ai_model_api_name:
+            return await ChatModel.objects.filter(name=chat_model_name, ai_model_api__name=ai_model_api_name).afirst()
+        return await ChatModel.objects.filter(name=chat_model_name).afirst()
+
     @staticmethod
     async def aget_voice_model_config(user: KhojUser) -> Optional[VoiceModelOption]:
         voice_model_config = await UserVoiceModelConfig.objects.filter(user=user).prefetch_related("setting").afirst()

src/khoj/database/migrations/0089_chatmodel_price_tier_and_more.py

@@ -0,0 +1,34 @@
+# Generated by Django 5.1.8 on 2025-04-18 15:15
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("database", "0088_ratelimitrecord"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="chatmodel",
+            name="price_tier",
+            field=models.CharField(choices=[("free", "Free"), ("standard", "Standard")], default="free", max_length=20),
+        ),
+        migrations.AddField(
+            model_name="speechtotextmodeloptions",
+            name="price_tier",
+            field=models.CharField(choices=[("free", "Free"), ("standard", "Standard")], default="free", max_length=20),
+        ),
+        migrations.AddField(
+            model_name="texttoimagemodelconfig",
+            name="price_tier",
+            field=models.CharField(choices=[("free", "Free"), ("standard", "Standard")], default="free", max_length=20),
+        ),
+        migrations.AddField(
+            model_name="voicemodeloption",
+            name="price_tier",
+            field=models.CharField(
+                choices=[("free", "Free"), ("standard", "Standard")], default="standard", max_length=20
+            ),
+        ),
+    ]

src/khoj/database/models/__init__.py

@@ -195,6 +195,11 @@ class AiModelApi(DbBaseModel):
         return self.name
 
 
+class PriceTier(models.TextChoices):
+    FREE = "free"
+    STANDARD = "standard"
+
+
 class ChatModel(DbBaseModel):
     class ModelType(models.TextChoices):
         OPENAI = "openai"
@@ -207,6 +212,7 @@ class ChatModel(DbBaseModel):
     tokenizer = models.CharField(max_length=200, default=None, null=True, blank=True)
     name = models.CharField(max_length=200, default="bartowski/Meta-Llama-3.1-8B-Instruct-GGUF")
     model_type = models.CharField(max_length=200, choices=ModelType.choices, default=ModelType.OFFLINE)
+    price_tier = models.CharField(max_length=20, choices=PriceTier.choices, default=PriceTier.FREE)
     vision_enabled = models.BooleanField(default=False)
     ai_model_api = models.ForeignKey(AiModelApi, on_delete=models.CASCADE, default=None, null=True, blank=True)
     description = models.TextField(default=None, null=True, blank=True)
@@ -219,6 +225,7 @@ class ChatModel(DbBaseModel):
 class VoiceModelOption(DbBaseModel):
     model_id = models.CharField(max_length=200)
     name = models.CharField(max_length=200)
+    price_tier = models.CharField(max_length=20, choices=PriceTier.choices, default=PriceTier.STANDARD)
 
 
 class Agent(DbBaseModel):
@@ -452,6 +459,17 @@ class ServerChatSettings(DbBaseModel):
         WebScraper, on_delete=models.CASCADE, default=None, null=True, blank=True, related_name="web_scraper"
     )
 
+    def clean(self):
+        error = {}
+        if self.chat_default and self.chat_default.price_tier != PriceTier.FREE:
+            error["chat_default"] = "Set the price tier of this chat model to free or use a free tier chat model."
+        if error:
+            raise ValidationError(error)
+
+    def save(self, *args, **kwargs):
+        self.clean()
+        super().save(*args, **kwargs)
+
 
 class LocalOrgConfig(DbBaseModel):
     input_files = models.JSONField(default=list, null=True)
@@ -534,6 +552,7 @@ class TextToImageModelConfig(DbBaseModel):
 
     model_name = models.CharField(max_length=200, default="dall-e-3")
     model_type = models.CharField(max_length=200, choices=ModelType.choices, default=ModelType.OPENAI)
+    price_tier = models.CharField(max_length=20, choices=PriceTier.choices, default=PriceTier.FREE)
     api_key = models.CharField(max_length=200, default=None, null=True, blank=True)
     ai_model_api = models.ForeignKey(AiModelApi, on_delete=models.CASCADE, default=None, null=True, blank=True)
 
@@ -571,6 +590,7 @@ class SpeechToTextModelOptions(DbBaseModel):
 
     model_name = models.CharField(max_length=200, default="base")
     model_type = models.CharField(max_length=200, choices=ModelType.choices, default=ModelType.OFFLINE)
+    price_tier = models.CharField(max_length=20, choices=PriceTier.choices, default=PriceTier.FREE)
     ai_model_api = models.ForeignKey(AiModelApi, on_delete=models.CASCADE, default=None, null=True, blank=True)
 
     def __str__(self):

src/khoj/routers/api_agents.py

@@ -12,7 +12,7 @@ from pydantic import BaseModel
 from starlette.authentication import has_required_scope, requires
 
 from khoj.database.adapters import AgentAdapters, ConversationAdapters, EntryAdapters
-from khoj.database.models import Agent, Conversation, KhojUser
+from khoj.database.models import Agent, Conversation, KhojUser, PriceTier
 from khoj.routers.helpers import CommonQueryParams, acheck_if_safe_prompt
 from khoj.utils.helpers import (
     ConversationCommand,
@@ -125,8 +125,20 @@ async def get_agent_by_conversation(
     else:
         agent = await AgentAdapters.aget_default_agent()
 
+    if agent is None:
+        return Response(
+            content=json.dumps({"error": f"Agent for conversation id {conversation_id} not found for user {user}."}),
+            media_type="application/json",
+            status_code=404,
+        )
+
+    chat_model = await AgentAdapters.aget_agent_chat_model(agent, user)
+    if is_subscribed or chat_model.price_tier == PriceTier.FREE:
+        agent_chat_model = chat_model.name
+    else:
+        agent_chat_model = None
+
     has_files = agent.fileobject_set.exists()
-    agent.chat_model = await AgentAdapters.aget_agent_chat_model(agent, user)
 
     agents_packet = {
         "slug": agent.slug,
@@ -137,7 +149,7 @@ async def get_agent_by_conversation(
         "color": agent.style_color,
         "icon": agent.style_icon,
         "privacy_level": agent.privacy_level,
-        "chat_model": agent.chat_model.name if is_subscribed else None,
+        "chat_model": agent_chat_model,
         "has_files": has_files,
         "input_tools": agent.input_tools,
         "output_modes": agent.output_modes,
@@ -249,7 +261,11 @@ async def update_hidden_agent(
     user: KhojUser = request.user.object
 
     subscribed = has_required_scope(request, ["premium"])
-    chat_model = body.chat_model if subscribed else None
+    chat_model = await ConversationAdapters.aget_chat_model_by_name(body.chat_model)
+    if subscribed or chat_model.price_tier == PriceTier.FREE:
+        agent_chat_model = body.chat_model
+    else:
+        agent_chat_model = None
 
     selected_agent = await AgentAdapters.aget_agent_by_slug(body.slug, user)
 
@@ -264,7 +280,7 @@ async def update_hidden_agent(
         user=user,
         slug=body.slug,
         persona=body.persona,
-        chat_model=chat_model,
+        chat_model=agent_chat_model,
         input_tools=body.input_tools,
         output_modes=body.output_modes,
         existing_agent=selected_agent,
@@ -295,7 +311,11 @@ async def create_hidden_agent(
     user: KhojUser = request.user.object
 
     subscribed = has_required_scope(request, ["premium"])
-    chat_model = body.chat_model if subscribed else None
+    chat_model = await ConversationAdapters.aget_chat_model_by_name(body.chat_model)
+    if subscribed or chat_model.price_tier == PriceTier.FREE:
+        agent_chat_model = body.chat_model
+    else:
+        agent_chat_model = None
 
     conversation = await ConversationAdapters.aget_conversation_by_user(user=user, conversation_id=conversation_id)
     if not conversation:
@@ -320,7 +340,7 @@ async def create_hidden_agent(
         user=user,
         slug=body.slug,
         persona=body.persona,
-        chat_model=chat_model,
+        chat_model=agent_chat_model,
         input_tools=body.input_tools,
         output_modes=body.output_modes,
         existing_agent=None,
@@ -364,7 +384,11 @@ async def create_agent(
         )
 
     subscribed = has_required_scope(request, ["premium"])
-    chat_model = body.chat_model if subscribed else None
+    chat_model = await ConversationAdapters.aget_chat_model_by_name(body.chat_model)
+    if subscribed or chat_model.price_tier == PriceTier.FREE:
+        agent_chat_model = body.chat_model
+    else:
+        agent_chat_model = None
 
     agent = await AgentAdapters.aupdate_agent(
         user,
@@ -373,7 +397,7 @@ async def create_agent(
         body.privacy_level,
         body.icon,
         body.color,
-        chat_model,
+        agent_chat_model,
         body.files,
         body.input_tools,
         body.output_modes,
@@ -431,7 +455,11 @@ async def update_agent(
         )
 
     subscribed = has_required_scope(request, ["premium"])
-    chat_model = body.chat_model if subscribed else None
+    chat_model = await ConversationAdapters.aget_chat_model_by_name(body.chat_model)
+    if subscribed or chat_model.price_tier == PriceTier.FREE:
+        agent_chat_model = body.chat_model
+    else:
+        agent_chat_model = None
 
     agent = await AgentAdapters.aupdate_agent(
         user,
@@ -440,7 +468,7 @@ async def update_agent(
         body.privacy_level,
         body.icon,
         body.color,
-        chat_model,
+        agent_chat_model,
         body.files,
         body.input_tools,
         body.output_modes,

src/khoj/routers/api_model.py

@@ -2,13 +2,18 @@ import json
 import logging
 from typing import Dict, Optional, Union
 
-from fastapi import APIRouter, HTTPException, Request
+from fastapi import APIRouter, Request
 from fastapi.requests import Request
 from fastapi.responses import Response
 from starlette.authentication import has_required_scope, requires
 
-from khoj.database import adapters
+from khoj.database.adapters import ConversationAdapters
-from khoj.database.adapters import ConversationAdapters, EntryAdapters
+from khoj.database.models import (
+    ChatModel,
+    PriceTier,
+    TextToImageModelConfig,
+    VoiceModelOption,
+)
 from khoj.routers.helpers import update_telemetry_state
 
 api_model = APIRouter()
@@ -53,13 +58,24 @@ def get_user_chat_model(
 
 
 @api_model.post("/chat", status_code=200)
-@requires(["authenticated", "premium"])
+@requires(["authenticated"])
 async def update_chat_model(
     request: Request,
     id: str,
     client: Optional[str] = None,
 ):
     user = request.user.object
+    subscribed = has_required_scope(request, ["premium"])
+
+    # Validate if model can be switched
+    chat_model = await ChatModel.objects.filter(id=int(id)).afirst()
+    if chat_model is None:
+        return Response(status_code=404, content=json.dumps({"status": "error", "message": "Chat model not found"}))
+    if not subscribed and chat_model.price_tier != PriceTier.FREE:
+        raise Response(
+            status_code=403,
+            content=json.dumps({"status": "error", "message": "Subscribe to switch to this chat model"}),
+        )
 
     new_config = await ConversationAdapters.aset_user_conversation_processor(user, int(id))
 
@@ -78,13 +94,24 @@ async def update_chat_model(
 
 
 @api_model.post("/voice", status_code=200)
-@requires(["authenticated", "premium"])
+@requires(["authenticated"])
 async def update_voice_model(
     request: Request,
     id: str,
     client: Optional[str] = None,
 ):
     user = request.user.object
+    subscribed = has_required_scope(request, ["premium"])
+
+    # Validate if model can be switched
+    voice_model = await VoiceModelOption.objects.filter(id=int(id)).afirst()
+    if voice_model is None:
+        return Response(status_code=404, content=json.dumps({"status": "error", "message": "Voice model not found"}))
+    if not subscribed and voice_model.price_tier != PriceTier.FREE:
+        raise Response(
+            status_code=403,
+            content=json.dumps({"status": "error", "message": "Subscribe to switch to this voice model"}),
+        )
 
     new_config = await ConversationAdapters.aset_user_voice_model(user, id)
 
@@ -111,8 +138,15 @@ async def update_paint_model(
     user = request.user.object
     subscribed = has_required_scope(request, ["premium"])
 
-    if not subscribed:
+    # Validate if model can be switched
-        raise HTTPException(status_code=403, detail="User is not subscribed to premium")
+    image_model = await TextToImageModelConfig.objects.filter(id=int(id)).afirst()
+    if image_model is None:
+        return Response(status_code=404, content=json.dumps({"status": "error", "message": "Image model not found"}))
+    if not subscribed and image_model.price_tier != PriceTier.FREE:
+        raise Response(
+            status_code=403,
+            content=json.dumps({"status": "error", "message": "Subscribe to switch to this image model"}),
+        )
 
     new_config = await ConversationAdapters.aset_user_text_to_image_model(user, int(id))
 

src/khoj/routers/helpers.py

@@ -2364,6 +2364,7 @@ def get_user_config(user: KhojUser, request: Request, is_detailed: bool = False)
                 "id": chat_model.id,
                 "strengths": chat_model.strengths,
                 "description": chat_model.description,
+                "tier": chat_model.price_tier,
             }
         )
 
@@ -2371,12 +2372,24 @@ def get_user_config(user: KhojUser, request: Request, is_detailed: bool = False)
     paint_model_options = ConversationAdapters.get_text_to_image_model_options().all()
     all_paint_model_options = list()
     for paint_model in paint_model_options:
-        all_paint_model_options.append({"name": paint_model.model_name, "id": paint_model.id})
+        all_paint_model_options.append(
+            {
+                "name": paint_model.model_name,
+                "id": paint_model.id,
+                "tier": paint_model.price_tier,
+            }
+        )
 
     voice_models = ConversationAdapters.get_voice_model_options()
     voice_model_options = list()
     for voice_model in voice_models:
-        voice_model_options.append({"name": voice_model.name, "id": voice_model.model_id})
+        voice_model_options.append(
+            {
+                "name": voice_model.name,
+                "id": voice_model.model_id,
+                "tier": voice_model.price_tier,
+            }
+        )
 
     if len(voice_model_options) == 0:
         eleven_labs_enabled = False