diff --git a/apps/web/client/.env.example b/apps/web/client/.env.example
index e193b284a2..3d83d47683 100644
--- a/apps/web/client/.env.example
+++ b/apps/web/client/.env.example
@@ -8,6 +8,9 @@ SUPABASE_SERVICE_ROLE_KEY="<Your Supabase service role key>"
 
 # OpenRouter - Enables AI chat. Other providers are optional below
 OPENROUTER_API_KEY="<Your api key from https://openrouter.ai/settings/keys>"
+# Optional: override the OpenRouter API base URL (e.g. for self-hosted proxies or custom endpoints)
+# Defaults to https://openrouter.ai/api/v1 when unset
+# OPENROUTER_BASE_URL="https://your-proxy.example.com/api/v1"
 
 # Codesandbox - Used to host user apps. Other providers may be supported in the future. May be optional in the future.
 CSB_API_KEY="<Your api key from https://codesandbox.io/t/api>"
diff --git a/packages/ai/src/chat/providers.ts b/packages/ai/src/chat/providers.ts
index 3dd4eb6582..50bbc76f17 100644
--- a/packages/ai/src/chat/providers.ts
+++ b/packages/ai/src/chat/providers.ts
@@ -45,10 +45,28 @@ export function initModel({
     };
 }
 
+/**
+ * Returns the base URL for the OpenRouter provider.
+ *
+ * The lookup order is:
+ *   1. `OPENROUTER_BASE_URL` environment variable (explicit override)
+ *   2. The default OpenRouter API endpoint
+ *
+ * This allows self-hosted deployments and proxy setups to point Onlook at a
+ * custom endpoint without modifying source code.
+ */
+function getOpenRouterBaseUrl(): string | undefined {
+    return process.env.OPENROUTER_BASE_URL || undefined;
+}
+
 function getOpenRouterProvider(model: OPENROUTER_MODELS): LanguageModel {
     if (!process.env.OPENROUTER_API_KEY) {
         throw new Error('OPENROUTER_API_KEY must be set');
     }
-    const openrouter = createOpenRouter({ apiKey: process.env.OPENROUTER_API_KEY });
+    const baseURL = getOpenRouterBaseUrl();
+    const openrouter = createOpenRouter({
+        apiKey: process.env.OPENROUTER_API_KEY,
+        ...(baseURL && { baseURL }),
+    });
     return openrouter(model);
 }