diff --git a/src/ClaudeDo.Ui/Helpers/StreamLineFormatter.cs b/src/ClaudeDo.Ui/Helpers/StreamLineFormatter.cs
index aec50f7..1990bed 100644
--- a/src/ClaudeDo.Ui/Helpers/StreamLineFormatter.cs
+++ b/src/ClaudeDo.Ui/Helpers/StreamLineFormatter.cs
@@ -69,7 +69,55 @@ public class StreamLineFormatter
         }
     }
 
-    private static string? FormatAssistant(JsonElement root) => null;
+    private static string? FormatAssistant(JsonElement root)
+    {
+        if (!TryGetContentArray(root, out var content))
+            return null;
+
+        var sb = new StringBuilder();
+        foreach (var block in content.EnumerateArray())
+        {
+            if (block.ValueKind != JsonValueKind.Object) continue;
+            if (!block.TryGetProperty("type", out var blockTypeProp)) continue;
+
+            switch (blockTypeProp.GetString())
+            {
+                case "text":
+                    if (block.TryGetProperty("text", out var textProp))
+                    {
+                        var text = textProp.GetString();
+                        if (!string.IsNullOrEmpty(text))
+                        {
+                            sb.Append(text);
+                            if (!text.EndsWith('\n')) sb.Append('\n');
+                        }
+                    }
+                    break;
+
+                case "tool_use":
+                    // Filled in by a later task.
+                    break;
+
+                case "thinking":
+                default:
+                    // Filtered.
+                    break;
+            }
+        }
+
+        return sb.Length == 0 ? null : sb.ToString();
+    }
+
+    private static bool TryGetContentArray(JsonElement root, out JsonElement content)
+    {
+        content = default;
+        if (!root.TryGetProperty("message", out var message)) return false;
+        if (message.ValueKind != JsonValueKind.Object) return false;
+        if (!message.TryGetProperty("content", out var c)) return false;
+        if (c.ValueKind != JsonValueKind.Array) return false;
+        content = c;
+        return true;
+    }
 
     private static string? FormatUser(JsonElement root) => null;