diff --git a/frontend/js/ai.js b/frontend/js/ai.js
index f31bc0f..f3d3ab4 100644
--- a/frontend/js/ai.js
+++ b/frontend/js/ai.js
@@ -239,7 +239,10 @@ export async function createAIToolbar(container, getEditorView) {
     try {
       const result = await aiAction('inline-complete', text);
       replaceSelection(v, result, 'append');
-    } catch (e) { showToast('AI: ' + e.message, 'error'); }
+      showToast('AI: complétion ajoutée', 'success');
+    } catch (e) {
+      showToast('AI: ' + (String(e.message || e).includes('401') ? 'clé API invalide' : e.message), 'error');
+    }
   });
 
   // ── Edit menu ──
@@ -296,7 +299,10 @@ export async function createAIToolbar(container, getEditorView) {
     try {
       const result = await aiAction('rewrite', text, { instruction });
       replaceSelection(v, result);
-    } catch (e) { showToast('AI: ' + e.message, 'error'); }
+      showToast('AI: texte réécrit', 'success');
+    } catch (e) {
+      showToast('AI: ' + (String(e.message || e).includes('401') ? 'clé API invalide' : e.message), 'error');
+    }
   });
 
   // ── Toolbox menu ──
@@ -324,11 +330,24 @@ export async function createAIToolbar(container, getEditorView) {
     const v = ev();
     if (!v) return;
     const text = getSelection(v);
-    if (!text.trim()) return;
+    if (!text.trim()) {
+      showToast('AI: sélectionnez du texte à traiter', 'warning');
+      return;
+    }
     try {
       const result = await aiAction(endpoint, text, extra);
       replaceSelection(v, result, mode);
-    } catch (e) { showToast('AI: ' + e.message, 'error'); }
+      showToast('AI: texte traité', 'success');
+    } catch (e) {
+      const msg = String(e.message || e);
+      if (msg.includes('401')) {
+        showToast('AI: clé API invalide. Vérifiez DEEPSEEK_API_KEY dans .env', 'error');
+      } else if (msg.includes('402') || msg.includes('429')) {
+        showToast('AI: quota dépassé ou paiement requis', 'error');
+      } else {
+        showToast('AI: ' + msg, 'error');
+      }
+    }
   }
 
   // ── Keyboard shortcut Ctrl+J for inline completion ──