From 83a4e3b66b77a0ba2c9b92aabe709dd571827f1d Mon Sep 17 00:00:00 2001
From: Matthew Zeng <mzeng@openai.com>
Date: Mon, 4 May 2026 10:20:58 -0700
Subject: [PATCH] [mcp-apps] Persist MCP Apps specific tool call end event.
 (#20853)

- [x] Persist a special type of MCP tool calls for triggering MCP App,
this type of mcp tool calls has 'mcpAppResourceUri` set. These events
are needed so that the Codex App can correctly render the MCP App after
resume.
---
 codex-rs/rollout/src/policy.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/codex-rs/rollout/src/policy.rs b/codex-rs/rollout/src/policy.rs
index 4115aa4ce..e9034fc8e 100644
--- a/codex-rs/rollout/src/policy.rs
+++ b/codex-rs/rollout/src/policy.rs
@@ -117,6 +117,9 @@ fn event_msg_persistence_mode(ev: &EventMsg) -> Option<EventPersistenceMode> {
                 None
             }
         }
+        EventMsg::McpToolCallEnd(event) if event.mcp_app_resource_uri.is_some() => {
+            Some(EventPersistenceMode::Limited)
+        }
         EventMsg::Error(_)
         | EventMsg::GuardianAssessment(_)
         | EventMsg::WebSearchEnd(_)