From 33dc93e4d2913ba940213ede693b84ebaf80b3f6 Mon Sep 17 00:00:00 2001
From: jif-oai <jif@openai.com>
Date: Tue, 3 Feb 2026 18:05:02 +0000
Subject: [PATCH] Enable parallel shell tools (#10505)

Summary
- mark the shell-related tools as supporting parallel tool calls so
exec_command, shell_command, etc. can run concurrently
- update expectations in tool parallelism tests to reflect the new
parallel behavior
- drop the unused serial duration helper from the suite

Testing
- Not run (not requested)
---
 codex-rs/core/src/tools/spec.rs               | 19 ++++++++++++++-----
 codex-rs/core/tests/suite/tool_parallelism.rs | 15 ++++-----------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/codex-rs/core/src/tools/spec.rs b/codex-rs/core/src/tools/spec.rs
index bd37e8bcc..c0fd1d022 100644
--- a/codex-rs/core/src/tools/spec.rs
+++ b/codex-rs/core/src/tools/spec.rs
@@ -1258,13 +1258,19 @@ pub(crate) fn build_specs(
 
     match &config.shell_type {
         ConfigShellToolType::Default => {
-            builder.push_spec(create_shell_tool(config.request_rule_enabled));
+            builder.push_spec_with_parallel_support(
+                create_shell_tool(config.request_rule_enabled),
+                true,
+            );
         }
         ConfigShellToolType::Local => {
-            builder.push_spec(ToolSpec::LocalShell {});
+            builder.push_spec_with_parallel_support(ToolSpec::LocalShell {}, true);
         }
         ConfigShellToolType::UnifiedExec => {
-            builder.push_spec(create_exec_command_tool(config.request_rule_enabled));
+            builder.push_spec_with_parallel_support(
+                create_exec_command_tool(config.request_rule_enabled),
+                true,
+            );
             builder.push_spec(create_write_stdin_tool());
             builder.register_handler("exec_command", unified_exec_handler.clone());
             builder.register_handler("write_stdin", unified_exec_handler);
@@ -1273,7 +1279,10 @@ pub(crate) fn build_specs(
             // Do nothing.
         }
         ConfigShellToolType::ShellCommand => {
-            builder.push_spec(create_shell_command_tool(config.request_rule_enabled));
+            builder.push_spec_with_parallel_support(
+                create_shell_command_tool(config.request_rule_enabled),
+                true,
+            );
         }
     }
 
@@ -1982,7 +1991,7 @@ mod tests {
         });
         let (tools, _) = build_specs(&tools_config, None, &[]).build();
 
-        assert!(!find_tool(&tools, "exec_command").supports_parallel_tool_calls);
+        assert!(find_tool(&tools, "exec_command").supports_parallel_tool_calls);
         assert!(!find_tool(&tools, "write_stdin").supports_parallel_tool_calls);
         assert!(find_tool(&tools, "grep_files").supports_parallel_tool_calls);
         assert!(find_tool(&tools, "list_dir").supports_parallel_tool_calls);
diff --git a/codex-rs/core/tests/suite/tool_parallelism.rs b/codex-rs/core/tests/suite/tool_parallelism.rs
index 0e03bbc26..955b2f7ec 100644
--- a/codex-rs/core/tests/suite/tool_parallelism.rs
+++ b/codex-rs/core/tests/suite/tool_parallelism.rs
@@ -77,13 +77,6 @@ fn assert_parallel_duration(actual: Duration) {
     );
 }
 
-fn assert_serial_duration(actual: Duration) {
-    assert!(
-        actual >= Duration::from_millis(500),
-        "expected serial execution to take longer, got {actual:?}"
-    );
-}
-
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn read_file_tools_run_in_parallel() -> anyhow::Result<()> {
     skip_if_no_network!(Ok(()));
@@ -147,7 +140,7 @@ async fn read_file_tools_run_in_parallel() -> anyhow::Result<()> {
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn non_parallel_tools_run_serially() -> anyhow::Result<()> {
+async fn shell_tools_run_in_parallel() -> anyhow::Result<()> {
     skip_if_no_network!(Ok(()));
 
     let server = start_mock_server().await;
@@ -174,13 +167,13 @@ async fn non_parallel_tools_run_serially() -> anyhow::Result<()> {
     mount_sse_sequence(&server, vec![first_response, second_response]).await;
 
     let duration = run_turn_and_measure(&test, "run shell_command twice").await?;
-    assert_serial_duration(duration);
+    assert_parallel_duration(duration);
 
     Ok(())
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn mixed_tools_fall_back_to_serial() -> anyhow::Result<()> {
+async fn mixed_parallel_tools_run_in_parallel() -> anyhow::Result<()> {
     skip_if_no_network!(Ok(()));
 
     let server = start_mock_server().await;
@@ -208,7 +201,7 @@ async fn mixed_tools_fall_back_to_serial() -> anyhow::Result<()> {
     mount_sse_sequence(&server, vec![first_response, second_response]).await;
 
     let duration = run_turn_and_measure(&test, "mix tools").await?;
-    assert_serial_duration(duration);
+    assert_parallel_duration(duration);
 
     Ok(())
 }