From f576c9b5ae5c1b980592a655abb8bcb2cfdd73a2 Mon Sep 17 00:00:00 2001
From: Charles Chen <charleschen@openai.com>
Date: Fri, 15 May 2026 20:09:38 -0700
Subject: [PATCH] Preserve MCP metadata

---
 .../exec/src/event_processor_with_jsonl_output.rs  |  1 +
 codex-rs/exec/src/exec_events.rs                   |  3 +++
 .../exec/tests/event_processor_with_json_output.rs | 14 ++++++++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/codex-rs/exec/src/event_processor_with_jsonl_output.rs b/codex-rs/exec/src/event_processor_with_jsonl_output.rs
index 045baacc7b..781d852d5d 100644
--- a/codex-rs/exec/src/event_processor_with_jsonl_output.rs
+++ b/codex-rs/exec/src/event_processor_with_jsonl_output.rs
@@ -224,6 +224,7 @@ impl EventProcessorWithJsonOutput {
                     result: result.map(|result| McpToolCallItemResult {
                         content: result.content,
                         structured_content: result.structured_content,
+                        meta: result.meta,
                     }),
                     error: error.map(|error| McpToolCallItemError {
                         message: error.message,
diff --git a/codex-rs/exec/src/exec_events.rs b/codex-rs/exec/src/exec_events.rs
index 4a84ef7494..8d6c5d96e6 100644
--- a/codex-rs/exec/src/exec_events.rs
+++ b/codex-rs/exec/src/exec_events.rs
@@ -267,6 +267,9 @@ pub struct McpToolCallItemResult {
     // easy to export.
     pub content: Vec<JsonValue>,
     pub structured_content: Option<JsonValue>,
+    #[serde(rename = "_meta", default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional, rename = "_meta")]
+    pub meta: Option<JsonValue>,
 }
 
 /// Error details reported by a failed MCP tool invocation.
diff --git a/codex-rs/exec/tests/event_processor_with_json_output.rs b/codex-rs/exec/tests/event_processor_with_json_output.rs
index efda58f412..1ef5c4e420 100644
--- a/codex-rs/exec/tests/event_processor_with_json_output.rs
+++ b/codex-rs/exec/tests/event_processor_with_json_output.rs
@@ -541,6 +541,7 @@ fn mcp_tool_call_begin_and_end_emit_item_events() {
                         result: Some(McpToolCallItemResult {
                             content: Vec::new(),
                             structured_content: None,
+                            meta: None,
                         }),
                         error: None,
                         status: McpToolCallStatus::Completed,
@@ -601,7 +602,7 @@ fn mcp_tool_call_failure_sets_failed_status() {
 }
 
 #[test]
-fn mcp_tool_call_defaults_arguments_and_preserves_structured_content() {
+fn mcp_tool_call_defaults_arguments_and_preserves_structured_content_and_meta() {
     let mut processor = EventProcessorWithJsonOutput::new(/*last_message_path*/ None);
 
     let started =
@@ -636,7 +637,11 @@ fn mcp_tool_call_defaults_arguments_and_preserves_structured_content() {
                         "text": "done",
                     })],
                     structured_content: Some(json!({ "status": "ok" })),
-                    meta: None,
+                    meta: Some(json!({
+                        "raw_messages": [
+                            { "ref_id": "abc123" }
+                        ],
+                    })),
                 })),
                 error: None,
                 duration_ms: Some(10),
@@ -682,6 +687,11 @@ fn mcp_tool_call_defaults_arguments_and_preserves_structured_content() {
                                 "text": "done",
                             })],
                             structured_content: Some(json!({ "status": "ok" })),
+                            meta: Some(json!({
+                                "raw_messages": [
+                                    { "ref_id": "abc123" }
+                                ],
+                            })),
                         }),
                         error: None,
                         status: McpToolCallStatus::Completed,