diff --git a/internal/service/static/main.js b/internal/service/static/main.js
index bb6c015..8e88a94 100644
--- a/internal/service/static/main.js
+++ b/internal/service/static/main.js
@@ -120,6 +120,7 @@ class Odidere {
     this.#clearAttachments();
     this.$textInput.value = '';
     this.$textInput.style.height = 'auto';
+    this.#updateSendButtonState();
   }
 
   // ====================
@@ -258,6 +259,7 @@ class Odidere {
       // Render the active path.
       const activePath = this.getActivePath();
       this.#renderMessages(activePath);
+      this.#updateSendButtonState();
     } catch (e) {
       console.error('failed to load history:', e);
       this.messagesMap.clear();
@@ -349,6 +351,7 @@ class Odidere {
     }
 
     this.#saveToStorage();
+    this.#updateSendButtonState();
     return messages;
   }
 
@@ -449,6 +452,7 @@ class Odidere {
     }
 
     this.#saveToStorage();
+    this.#updateSendButtonState();
   }
 
   /**
@@ -572,6 +576,7 @@ class Odidere {
     const maxHeight = parseFloat(computed.maxHeight);
     const newHeight = Math.min(textarea.scrollHeight, maxHeight);
     textarea.style.height = `${newHeight}px`;
+    this.#updateSendButtonState();
   };
 
   /**
@@ -592,6 +597,7 @@ class Odidere {
       this.attachments.push(file);
     }
     this.#renderAttachments();
+    this.#updateSendButtonState();
     this.$fileInput.value = '';
   }
 
@@ -1025,9 +1031,6 @@ class Odidere {
    */
   async #submitText() {
     const text = this.$textInput.value.trim();
-    const hasContent = text || this.attachments.length > 0;
-
-    if (!hasContent) return;
     if (this.isProcessing) return;
 
     this.#stopCurrentAudio();
@@ -1060,20 +1063,25 @@ class Odidere {
     this.currentController = new AbortController();
 
     try {
-      // Build the user message with text and attachments.
-      const userMessage = await this.#buildUserMessage(text, this.attachments);
-      const hasContent = text || this.attachments.length > 0 || audio;
-      if (!hasContent) {
-        this.#setLoadingState(false);
-        return;
-      }
+      const hasNewInput = text || this.attachments.length > 0 || audio;
 
       // Build messages array from active path + current user message.
       const activePath = this.getActivePath();
-      const messages = [
-        ...activePath.map(({ parent, children, id, meta, ...msg }) => msg),
-        userMessage,
-      ];
+      let messages;
+      let userMessage;
+
+      if (hasNewInput) {
+        userMessage = await this.#buildUserMessage(text, this.attachments);
+        messages = [
+          ...activePath.map(({ parent, children, id, meta, ...msg }) => msg),
+          userMessage,
+        ];
+      } else {
+        // Continue conversation: send existing history without a new user message.
+        messages = activePath.map(
+          ({ parent, children, id, meta, ...msg }) => msg,
+        );
+      }
 
       const payload = {
         messages,
@@ -1091,9 +1099,9 @@ class Odidere {
       // Clear attachments after building payload (before async operations).
       this.#clearAttachments();
 
-      // For text-only requests (no audio), add to history and render
-      // immediately. Use the returned messages (with IDs) for rendering.
-      if (!audio) {
+      // For text-only requests with new input, add to history and render
+      // immediately. Skip when continuing conversation (no new user message).
+      if (!audio && hasNewInput) {
         const appended = this.#appendHistory([userMessage]);
         this.#renderMessages(appended);
       }
@@ -1310,6 +1318,23 @@ class Odidere {
   // ====================
   // STATE
   // ====================
+  /**
+   * #updateSendButtonState enables the send button when there is text,
+   * attachments, or at least one message in the conversation history,
+   * and disables it otherwise.
+   */
+  #updateSendButtonState() {
+    const hasText = this.$textInput.value.trim().length > 0;
+    const hasAttachments = this.attachments.length > 0;
+    const hasHistory = this.messagesMap.size > 0;
+    const enabled = hasText || hasAttachments || hasHistory;
+    this.$send.disabled = !enabled;
+    this.$send.setAttribute(
+      'aria-label',
+      enabled ? 'Send message' : 'Start a conversation to enable send',
+    );
+  }
+
   /**
    * #setLoadingState updates UI to reflect loading state.
    * @param {boolean} loading
@@ -1813,6 +1838,7 @@ class Odidere {
   #removeAttachment(index) {
     this.attachments.splice(index, 1);
     this.#renderAttachments();
+    this.#updateSendButtonState();
   }
 
   /**