From 6e8785a021f4fd3c40d4f25b053e2f3070122998 Mon Sep 17 00:00:00 2001
From: Jack Mousseau <mousseau@openai.com>
Date: Thu, 5 Mar 2026 10:13:01 -0800
Subject: [PATCH] Return error when schema definitions collide

---
 codex-rs/app-server-protocol/src/export.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/codex-rs/app-server-protocol/src/export.rs b/codex-rs/app-server-protocol/src/export.rs
index aad5ab7233..cc67dd82dc 100644
--- a/codex-rs/app-server-protocol/src/export.rs
+++ b/codex-rs/app-server-protocol/src/export.rs
@@ -1154,6 +1154,14 @@ fn insert_into_namespace(
         .or_insert_with(|| Value::Object(Map::new()));
     match entry {
         Value::Object(map) => {
+            if let Some(existing) = map.get(&name) {
+                if existing != &schema {
+                    return Err(anyhow!(
+                        "conflicting schema definition for {namespace}/{name}"
+                    ));
+                }
+                return Ok(());
+            }
             map.insert(name, schema);
             Ok(())
         }