diff --git a/codex-rs/core/tests/common/agent_harness.rs b/codex-rs/core/tests/common/agent_harness.rs
index 6af6e86561..786815aed0 100644
--- a/codex-rs/core/tests/common/agent_harness.rs
+++ b/codex-rs/core/tests/common/agent_harness.rs
@@ -159,6 +159,15 @@ pub async fn run_fixture(dir: impl AsRef<Path>) -> Result<HarnessData> {
         events.push(next);
     }
 
+    loop {
+        let extra = match timeout(Duration::from_millis(200), codex.next_event()).await {
+            Ok(Ok(event)) => event,
+            Ok(Err(err)) => anyhow::bail!("error receiving extra event: {err}"),
+            Err(_) => break,
+        };
+        events.push(extra);
+    }
+
     let received = server
         .received_requests()
         .await
diff --git a/codex-rs/core/tests/suite/agent_harness.rs b/codex-rs/core/tests/suite/agent_harness.rs
index a1405d7a0f..4202b719e8 100644
--- a/codex-rs/core/tests/suite/agent_harness.rs
+++ b/codex-rs/core/tests/suite/agent_harness.rs
@@ -1,7 +1,9 @@
 use std::path::PathBuf;
 
 use core_test_support::agent_harness;
+use core_test_support::agent_harness::HarnessOutputs;
 use pretty_assertions::assert_eq;
+use serde_json::Value;
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn single_turn_fixture_matches_expectations() {
@@ -11,5 +13,70 @@ async fn single_turn_fixture_matches_expectations() {
         .await
         .expect("run agent harness");
 
-    assert_eq!(harness.actual, harness.expected);
+    assert_harness_outputs_match(&harness.actual, &harness.expected);
+}
+
+fn assert_harness_outputs_match(actual: &HarnessOutputs, expected: &HarnessOutputs) {
+    assert_value_matches(&actual.request, &expected.request, "request");
+    assert_eq!(
+        actual.events.len(),
+        expected.events.len(),
+        "event count mismatch: expected {} events but got {}",
+        expected.events.len(),
+        actual.events.len()
+    );
+    for (index, expected_event) in expected.events.iter().enumerate() {
+        let path = format!("events[{index}]");
+        let actual_event = actual
+            .events
+            .get(index)
+            .unwrap_or_else(|| panic!("missing actual event at {path}"));
+        assert_value_matches(actual_event, expected_event, &path);
+    }
+}
+
+fn assert_value_matches(actual: &Value, expected: &Value, path: &str) {
+    match expected {
+        Value::Object(expected_map) => {
+            let actual_map = actual
+                .as_object()
+                .unwrap_or_else(|| panic!("expected object at {path}, got {actual:?}"));
+            for (key, expected_value) in expected_map {
+                let next_path = if path.is_empty() {
+                    key.to_string()
+                } else {
+                    format!("{path}.{key}")
+                };
+                let actual_value = actual_map
+                    .get(key)
+                    .unwrap_or_else(|| panic!("missing field {next_path} in actual value"));
+                assert_value_matches(actual_value, expected_value, &next_path);
+            }
+        }
+        Value::Array(expected_items) => {
+            let actual_items = actual
+                .as_array()
+                .unwrap_or_else(|| panic!("expected array at {path}, got {actual:?}"));
+            assert_eq!(
+                actual_items.len(),
+                expected_items.len(),
+                "array length mismatch at {}",
+                path
+            );
+            for (index, expected_value) in expected_items.iter().enumerate() {
+                let next_path = if path.is_empty() {
+                    format!("[{index}]")
+                } else {
+                    format!("{path}[{index}]")
+                };
+                let actual_value = actual_items
+                    .get(index)
+                    .unwrap_or_else(|| panic!("missing array element at {next_path}"));
+                assert_value_matches(actual_value, expected_value, &next_path);
+            }
+        }
+        _ => {
+            assert_eq!(actual, expected, "mismatch at {path}");
+        }
+    }
 }