From e9c52566b88e11248f92a29ef443731a83e6880a Mon Sep 17 00:00:00 2001
From: Alex Clarke <alex.j.tusa@gmail.com>
Date: Wed, 15 Jul 2026 16:27:57 -0600
Subject: [PATCH] feat: Explicitly Prevent .undo usage in graph agents

---
 src/repl/mod.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/repl/mod.rs b/src/repl/mod.rs
index bf8b49b..a23cc88 100644
--- a/src/repl/mod.rs
+++ b/src/repl/mod.rs
@@ -976,6 +976,12 @@ pub async fn run_repl_command(
                 }
             },
             ".undo" => {
+                if let Some(name) = graph::active_agent_graph_name(ctx) {
+                    bail!(
+                        "Graph-based agent '{name}' does not support .undo. \
+                         The graph manages its own state."
+                    );
+                }
                 ctx.undo_last_exchange()?;
             }
             ".rebuild" => match args {