diff --git a/apps/nextjs/src/app/[locale]/boards/(content)/_creator.tsx b/apps/nextjs/src/app/[locale]/boards/(content)/_creator.tsx
index 16be5c478..99d1a2584 100644
--- a/apps/nextjs/src/app/[locale]/boards/(content)/_creator.tsx
+++ b/apps/nextjs/src/app/[locale]/boards/(content)/_creator.tsx
@@ -1,5 +1,6 @@
 import type { Metadata } from "next";
 import { Suspense } from "react";
+import { notFound } from "next/navigation";
 import { TRPCError } from "@trpc/server";
 
 // Placed here because gridstack styles are used for board content
@@ -50,7 +51,15 @@ export const createBoardContentPage = <TParams extends Record<string, unknown>>(
       const resolvedParams = await params;
       const queryClient = getQueryClient();
 
-      const [board, session] = await Promise.all([getInitialBoard(resolvedParams), auth()]);
+      const [board, session] = await Promise.all([
+        getInitialBoard(resolvedParams).catch((error) => {
+          if (error instanceof TRPCError && (error.code === "NOT_FOUND" || error.code === "BAD_REQUEST")) {
+            notFound();
+          }
+          throw error;
+        }),
+        auth(),
+      ]);
 
       const itemsMap = board.items.reduce((acc, item) => {
         const existing = acc.get(item.kind);
diff --git a/apps/nextjs/src/app/[locale]/manage/assistant/_components/assistant-configuration.tsx b/apps/nextjs/src/app/[locale]/manage/assistant/_components/assistant-configuration.tsx
index 8f8c538b4..f97c53e2f 100644
--- a/apps/nextjs/src/app/[locale]/manage/assistant/_components/assistant-configuration.tsx
+++ b/apps/nextjs/src/app/[locale]/manage/assistant/_components/assistant-configuration.tsx
@@ -462,7 +462,7 @@ export const AssistantConfiguration = () => {
             </Badge>
           }
         >
-          <SimpleGrid cols={{ base: 1, sm: 2 }}>
+          <Stack gap="md">
             <Select
               label={t("provider.title")}
               description={t(`provider.options.${provider}.description`)}
@@ -503,14 +503,14 @@ export const AssistantConfiguration = () => {
               onChange={(event) => changeBaseUrl(event.currentTarget.value)}
               placeholder="https://provider.example/v1"
             />
-          </SimpleGrid>
-          <TextInput
-            label={t("model.discoveryPath")}
-            description={t("model.discoveryPathDescription")}
-            value={modelDiscoveryPath}
-            onChange={(event) => changeModelDiscoveryPath(event.currentTarget.value)}
-            placeholder="/models"
-          />
+            <TextInput
+              label={t("model.discoveryPath")}
+              description={t("model.discoveryPathDescription")}
+              value={modelDiscoveryPath}
+              onChange={(event) => changeModelDiscoveryPath(event.currentTarget.value)}
+              placeholder="/models"
+            />
+          </Stack>
 
           {destinationChanged && (
             <Alert icon={<IconAlertTriangle size={18} />} color="yellow" title={t("destinationChanged.title")}>
diff --git a/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.spec.ts b/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.spec.ts
new file mode 100644
index 000000000..bec8b3b95
--- /dev/null
+++ b/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.spec.ts
@@ -0,0 +1,18 @@
+import { describe, expect, test } from "vitest";
+
+import { toProviderOptionsKey } from "./assistant-provider-options";
+
+describe("toProviderOptionsKey", () => {
+  test("converts the hyphenated provider name to the camelCase AI SDK provider option key", () => {
+    expect(toProviderOptionsKey("homarr-openrouter")).toBe("homarrOpenrouter");
+  });
+
+  test("matches the @ai-sdk/openai-compatible camelCase conversion", () => {
+    expect(toProviderOptionsKey("homarr-anthropic")).toBe("homarrAnthropic");
+    expect(toProviderOptionsKey("homarr-google-gemini")).toBe("homarrGoogleGemini");
+  });
+
+  test("leaves names without separators unchanged", () => {
+    expect(toProviderOptionsKey("homarr")).toBe("homarr");
+  });
+});
diff --git a/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.ts b/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.ts
new file mode 100644
index 000000000..04f6d2f6b
--- /dev/null
+++ b/apps/nextjs/src/app/api/assistant/chat/assistant-provider-options.ts
@@ -0,0 +1,17 @@
+/**
+ * The AI SDK resolves provider options by the provider name registered on the
+ * language model. The @ai-sdk/openai-compatible provider converts the raw
+ * provider name (for example `homarr-openrouter`) to camelCase
+ * (`homarrOpenrouter`) and warns when the raw key is still used. This helper
+ * mirrors that conversion so providerOptions reach the provider without a
+ * deprecation warning.
+ */
+export const toProviderOptionsKey = (name: string) =>
+  name
+    .split("-")
+    .filter(Boolean)
+    .map((segment, index) => {
+      if (index === 0) return segment;
+      return segment.charAt(0).toUpperCase() + segment.slice(1);
+    })
+    .join("");
diff --git a/apps/nextjs/src/app/api/assistant/chat/route.ts b/apps/nextjs/src/app/api/assistant/chat/route.ts
index e3b5ae254..4e303f42a 100644
--- a/apps/nextjs/src/app/api/assistant/chat/route.ts
+++ b/apps/nextjs/src/app/api/assistant/chat/route.ts
@@ -3,7 +3,7 @@ import { hkdfSync } from "node:crypto";
 import { createOpenAICompatible } from "@ai-sdk/openai-compatible";
 import type { MetadataExtractor } from "@ai-sdk/openai-compatible";
 import type { ToolSet, UIMessage } from "ai";
-import { convertToModelMessages, jsonSchema, stepCountIs, streamText, tool } from "ai";
+import { convertToModelMessages, createUIMessageStream, createUIMessageStreamResponse, jsonSchema, stepCountIs, streamText, tool } from "ai";
 import { parse, stringify } from "superjson";
 import { z } from "zod/v4";
 
@@ -27,6 +27,7 @@ import {
 } from "@homarr/definitions";
 
 import { browserToolContracts } from "~/components/assistant/assistant-tool-contracts";
+import { env as appEnv } from "~/env";
 import type {
   AssistantMessageMetadata,
   AssistantRequestStep,
@@ -43,6 +44,7 @@ import {
   normalizeOpenRouterWebSearchSources,
   withOpenRouterWebSearch,
 } from "./assistant-openrouter";
+import { toProviderOptionsKey } from "./assistant-provider-options";
 import { assistantExecutionPolicy } from "./assistant-execution-policy";
 import { getAssistantStreamErrorMessage } from "./assistant-stream-error";
 import { getSafeAssistantToolError } from "./assistant-tool-error";
@@ -322,6 +324,31 @@ const getProcedureTypeMap = () => {
   );
 };
 
+const createDemoAssistantResponse = (request: z.infer<typeof requestSchema>) => {
+  const delay = (ms: number) => new Promise<void>((resolve) => setTimeout(resolve, ms));
+  const text =
+    "This is the Homarr demo assistant. It is running in preview/mock mode, so it responds with a canned answer instead of calling a real language model. In a real deployment, an administrator configures a provider and a model for full conversations.";
+  const responseId = crypto.randomUUID();
+  const partId = crypto.randomUUID();
+  const chunkTexts = text.match(/.{1,3}/gs) ?? [text];
+
+  const stream = createUIMessageStream<UIMessage>({
+    originalMessages: request.messages as UIMessage[],
+    execute: async ({ writer }) => {
+      writer.write({ type: "start", messageId: responseId });
+      writer.write({ type: "text-start", id: partId });
+      for (const chunk of chunkTexts) {
+        writer.write({ type: "text-delta", id: partId, delta: chunk });
+        await delay(18);
+      }
+      writer.write({ type: "text-end", id: partId });
+      writer.write({ type: "finish", finishReason: "stop" });
+    },
+  });
+
+  return createUIMessageStreamResponse({ stream });
+};
+
 export async function POST(request: Request) {
   const contentLength = Number(request.headers.get("content-length") ?? 0);
   if (contentLength > 2_000_000) {
@@ -359,10 +386,7 @@ export async function POST(request: Request) {
   const configuration = await db.query.assistantConfigurations.findFirst({
     where: eq(assistantConfigurations.id, "default"),
   });
-  const requiresApiKey = configuration ? assistantProviderRequiresApiKey(configuration.provider) : false;
-  if (!configuration?.enabled || !configuration.modelId || (requiresApiKey && !configuration.encryptedApiKey)) {
-    return Response.json({ error: "Homarr Assistant is not configured." }, { status: 503 });
-  }
+
   const thread = await db.query.assistantThreads.findFirst({
     where: and(eq(assistantThreads.id, parsed.data.id), eq(assistantThreads.userId, session.user.id)),
   });
@@ -370,6 +394,15 @@ export async function POST(request: Request) {
     return Response.json({ error: "Conversation not found." }, { status: 404 });
   }
 
+  if (appEnv.DEMO_MODE) {
+    return createDemoAssistantResponse(parsed.data);
+  }
+
+  const requiresApiKey = configuration ? assistantProviderRequiresApiKey(configuration.provider) : false;
+  if (!configuration?.enabled || !configuration.modelId || (requiresApiKey && !configuration.encryptedApiKey)) {
+    return Response.json({ error: "Homarr Assistant is not configured." }, { status: 503 });
+  }
+
   const context = createTRPCContext({ headers: request.headers, session });
   const requestStartedAt = Date.now();
   const requestId = crypto.randomUUID();
@@ -543,7 +576,7 @@ export async function POST(request: Request) {
       reasoning: parsed.data.reasoning === "auto" ? undefined : parsed.data.reasoning,
       providerOptions:
         configuration.provider === "openrouter" || openRouterServerToolsEnabled
-          ? { [providerName]: { usage: { include: true } } }
+          ? { [toProviderOptionsKey(providerName)]: { usage: { include: true } } }
           : undefined,
       toolApproval,
       experimental_toolApprovalSecret: getToolApprovalSecret(),
diff --git a/packages/api/src/router/assistant.ts b/packages/api/src/router/assistant.ts
index df40a253f..fa9279665 100644
--- a/packages/api/src/router/assistant.ts
+++ b/packages/api/src/router/assistant.ts
@@ -30,7 +30,7 @@ import {
 import type { createTRPCContext } from "../trpc";
 import { fetchOpenRouterGenerationTelemetryAsync } from "../assistant-generation-telemetry";
 import { verifyAssistantGenerationAccessToken } from "../assistant-generation-access";
-import { createTRPCRouter, permissionRequiredProcedure, protectedProcedure } from "../trpc";
+import { createTRPCRouter, isDemoMode, permissionRequiredProcedure, protectedProcedure } from "../trpc";
 import { boardRouter } from "./board";
 
 const adminProcedure = permissionRequiredProcedure.requiresPermission("admin");
@@ -448,6 +448,9 @@ export const assistantRouter = createTRPCRouter({
       },
     })
     .query(async ({ ctx }) => {
+      if (isDemoMode) {
+        return { enabled: true };
+      }
       const configuration = await getConfigurationAsync(ctx.db);
       const requiresApiKey = configuration ? assistantProviderRequiresApiKey(configuration.provider) : false;
       return {
@@ -495,6 +498,24 @@ export const assistantRouter = createTRPCRouter({
 
   getRuntimeOptions: protectedProcedure.query(async ({ ctx }) => {
     const configuration = await getConfigurationAsync(ctx.db);
+    if (isDemoMode) {
+      return {
+        provider: "homarr",
+        defaultModelId: "homarr-assistant",
+        models: [
+          {
+            id: "homarr-assistant",
+            name: "Homarr Assistant (Demo)",
+            description: null,
+            contextLength: null,
+            promptPrice: null,
+            completionPrice: null,
+            inputModalities: [],
+            toolSupport: "unknown" as const,
+          },
+        ],
+      };
+    }
     if (!configuration?.enabled || !configuration.modelId) {
       throw new TRPCError({ code: "PRECONDITION_FAILED", message: "Homarr Assistant is not configured." });
     }