From f148caa9a1d048cc3bd0d4e7dee3fdcb359f713e Mon Sep 17 00:00:00 2001
From: Ahmed Ibrahim <aibrahim@openai.com>
Date: Mon, 6 Apr 2026 20:19:07 -0700
Subject: [PATCH] codex: preserve forked null base instructions (#16964)

---
 codex-rs/app-server/src/codex_message_processor.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/codex-rs/app-server/src/codex_message_processor.rs b/codex-rs/app-server/src/codex_message_processor.rs
index c707922036..91641898d1 100644
--- a/codex-rs/app-server/src/codex_message_processor.rs
+++ b/codex-rs/app-server/src/codex_message_processor.rs
@@ -4363,6 +4363,13 @@ impl CodexMessageProcessor {
             developer_instructions,
             /*personality*/ None,
         );
+        if typesafe_overrides.base_instructions.is_none()
+            && let Ok(history) = RolloutRecorder::get_rollout_history(&rollout_path).await
+            && let Some(base_instructions) = history.get_base_instructions()
+        {
+            typesafe_overrides.base_instructions =
+                Some(base_instructions.map(|base_instructions| base_instructions.text));
+        }
         typesafe_overrides.ephemeral = ephemeral.then_some(true);
         // Derive a Config using the same logic as new conversation, honoring overrides if provided.
         let cloud_requirements = self.current_cloud_requirements();