diff --git a/examples/server/public/completion.js b/examples/server/public/completion.js
index 81c664520..54a0f22f5 100644
--- a/examples/server/public/completion.js
+++ b/examples/server/public/completion.js
@@ -5,6 +5,12 @@ const paramDefaults = {
 
 let generation_settings = null;
 
+export class CompletionError extends Error {
+  constructor(message, name, data) {
+    super(message);
+    this.name = name;
+  }
+};
 
 // Completes the prompt as a generator. Recommended for most use cases.
 //
@@ -39,6 +45,18 @@ export async function* llama(prompt, params = {}, config = {}) {
     signal: controller.signal,
   });
 
+  const status = response.status;
+  if (status !== 200) {
+    try {
+      const body = await response.json();
+      if (body && body.error && body.error.message) {
+        throw new CompletionError(body.error.message, 'ServerError');
+      }
+    } catch (err) {
+      throw new CompletionError(err.message, 'ServerError');
+    }
+  }
+
   const reader = response.body.getReader();
   const decoder = new TextDecoder();
 
diff --git a/examples/server/public/index.html b/examples/server/public/index.html
index 58a896591..f768d316f 100644
--- a/examples/server/public/index.html
+++ b/examples/server/public/index.html
@@ -285,6 +285,14 @@
         conv.lastModified = Date.now();
         localStorage.setItem(convId, JSON.stringify(conv));
       },
+      popMsg(convId) {
+        const conv = StorageUtils.getOneConversation(convId);
+        if (!conv) return;
+        const msg = conv.messages.pop();
+        conv.lastModified = Date.now();
+        localStorage.setItem(convId, JSON.stringify(conv));
+        return msg;
+      },
 
       // manage config
       getConfig() {
@@ -425,6 +433,7 @@
               top_p: this.config.top_p,
               max_tokens: this.config.max_tokens,
               ...(this.config.custom.length ? JSON.parse(this.config.custom) : {}),
+              ...(this.config.apiKey ? { api_key: this.config.apiKey } : {}),
             };
             const config = {
               controller: abortController,
@@ -457,13 +466,16 @@
             } else {
               console.error(error);
               alert(error);
-              this.inputMsg = this.pendingMsg.content || '';
+              // pop last user message
+              const lastUserMsg = StorageUtils.popMsg(currConvId);
+              this.inputMsg = lastUserMsg ? lastUserMsg.content : '';
             }
           }
 
           this.pendingMsg = null;
           this.isGenerating = false;
           this.stopGeneration = () => {};
+          this.fetchMessages();
         },
 
         // message actions
diff --git a/examples/server/server.cpp b/examples/server/server.cpp
index 5ece0473e..7f6fc65b7 100644
--- a/examples/server/server.cpp
+++ b/examples/server/server.cpp
@@ -2356,6 +2356,11 @@ int main(int argc, char ** argv) {
             "/v1/models",
         };
 
+        // If this is OPTIONS request, skip validation because browsers don't include Authorization header
+        if (req.method == "OPTIONS") {
+            return true;
+        }
+
         // If API key is not set, skip validation
         if (params.api_keys.empty()) {
             return true;