diff --git a/apps/opik-frontend/src/plugins/comet/AssistantSidebar.tsx b/apps/opik-frontend/src/plugins/comet/AssistantSidebar.tsx
index f4705a60a23..37a002dc59a 100644
--- a/apps/opik-frontend/src/plugins/comet/AssistantSidebar.tsx
+++ b/apps/opik-frontend/src/plugins/comet/AssistantSidebar.tsx
@@ -27,9 +27,11 @@ import useRunnerBridgeSync from "@/hooks/useRunnerBridgeSync";
 import { BASE_API_URL } from "@/api/api";
 import { Spinner } from "@/ui/spinner";
 import AssistantErrorState from "@/plugins/comet/AssistantErrorState";
+import {
+  ASSISTANT_DEV_BASE_URL,
+  IS_ASSISTANT_DEV,
+} from "@/plugins/comet/constants/assistant";
 
-const DEV_BASE_URL = import.meta.env.VITE_ASSISTANT_SIDEBAR_BASE_URL;
-const IS_DEV = import.meta.env.DEV;
 const BRIDGE_PROTOCOL_VERSION = 1;
 
 const LOADER_DEFAULT_WIDTH = 400;
@@ -219,7 +221,7 @@ const createBridge = (refs: BridgeRefs): AssistantSidebarBridge => ({
         );
         break;
       default:
-        if (IS_DEV) {
+        if (IS_ASSISTANT_DEV) {
           console.warn(
             `[AssistantBridge] Unhandled sidebar event: "${event}"`,
             data,
@@ -298,7 +300,7 @@ interface AssistantMeta {
 }
 
 function resolveManifestUrl(backendUrl: string | null): string | null {
-  if (DEV_BASE_URL) return `${DEV_BASE_URL}/manifest.json`;
+  if (ASSISTANT_DEV_BASE_URL) return `${ASSISTANT_DEV_BASE_URL}/manifest.json`;
   if (backendUrl) return `${backendUrl}/console/manifest.json`;
   return null;
 }
@@ -326,16 +328,16 @@ function useAssistantMeta(backendUrl: string | null): AssistantMeta | null {
       return {
         scriptUrl: `${manifestBase}/${manifest.js}`,
         cssUrl: manifest.css ? `${manifestBase}/${manifest.css}` : undefined,
-        shellUrl: `${manifestBase}/${manifest.shell}`,
+        shellUrl: `/assistant/${manifest.shell}`,
         version: manifest.ver,
       };
     },
-    enabled: !(IS_DEV && DEV_BASE_URL) && !!manifestUrl,
+    enabled: !IS_ASSISTANT_DEV && !!manifestUrl,
     staleTime: Infinity,
     retry: 1,
   });
 
-  if (IS_DEV && DEV_BASE_URL) return DEV_META;
+  if (IS_ASSISTANT_DEV) return DEV_META;
 
   return data ?? null;
 }
diff --git a/apps/opik-frontend/src/plugins/comet/constants/assistant.ts b/apps/opik-frontend/src/plugins/comet/constants/assistant.ts
new file mode 100644
index 00000000000..89b61154abf
--- /dev/null
+++ b/apps/opik-frontend/src/plugins/comet/constants/assistant.ts
@@ -0,0 +1,4 @@
+export const ASSISTANT_DEV_BASE_URL =
+  (import.meta.env.VITE_ASSISTANT_SIDEBAR_BASE_URL as string) ?? "";
+
+export const IS_ASSISTANT_DEV = ASSISTANT_DEV_BASE_URL !== "";
diff --git a/apps/opik-frontend/src/plugins/comet/useAssistantBackend.ts b/apps/opik-frontend/src/plugins/comet/useAssistantBackend.ts
index c9150b2df8e..26cf5dee293 100644
--- a/apps/opik-frontend/src/plugins/comet/useAssistantBackend.ts
+++ b/apps/opik-frontend/src/plugins/comet/useAssistantBackend.ts
@@ -2,8 +2,8 @@ import { useCallback, useEffect, useRef, useState } from "react";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import cometApi from "@/plugins/comet/api";
 import { useActiveWorkspaceName } from "@/store/AppStore";
+import { IS_ASSISTANT_DEV } from "@/plugins/comet/constants/assistant";
 
-const IS_DEV = import.meta.env.DEV;
 const HEALTH_POLL_INTERVAL_MS = 5000;
 const HEALTH_POLL_TIMEOUT_MS = 2 * 60 * 1000; // 2 minutes
 const HEALTH_KEEPALIVE_MS = 30_000; // 30s keepalive after ready
@@ -92,14 +92,14 @@ export default function useAssistantBackend(
       );
       return { baseUrl, enabled: true };
     },
-    enabled: !IS_DEV && configEnabled && !!workspaceName,
+    enabled: !IS_ASSISTANT_DEV && configEnabled && !!workspaceName,
     staleTime: Infinity,
     retry: 2,
   });
 
   const baseUrl = computeResult?.baseUrl ?? null;
   const computeEnabled = computeResult?.enabled ?? false;
-  const shouldPollHealth = !IS_DEV && !!baseUrl && computeEnabled;
+  const shouldPollHealth = !IS_ASSISTANT_DEV && !!baseUrl && computeEnabled;
 
   // Track when health polling started — only reset when baseUrl changes
   // (not on transient shouldPollHealth flickers)
@@ -218,8 +218,8 @@ export default function useAssistantBackend(
     queueMicrotask(() => resetBackend());
   }
 
-  // Dev mode — static URL, no network calls (queries are disabled via enabled: !IS_DEV)
-  if (IS_DEV) return DEV_RESULT;
+  // Dev mode or local override — static URL, no network calls
+  if (IS_ASSISTANT_DEV) return DEV_RESULT;
 
   if (computeResult && !computeResult.enabled)
     return notReadyResult(null, "disabled", retry, retryCount);