Limit payload traces in diagnostic logs (#37497)

## Why

High-volume request and streamed-response payloads can overwhelm the SQLite log database and diagnostic ring buffer used for reports.

## What changed

- Limit HTTP transport, SSE, and WebSocket diagnostics to `DEBUG` in persistent log sinks while leaving unrelated trace diagnostics available.
- Log known unhandled response events and delta events at `TRACE`, and surface unexpected event kinds at `DEBUG` without including their payloads.
- Report structured parse-error metadata instead of logging an unparseable SSE payload.

## Testing

- Cover filtering for transport, SSE, WebSocket, and unrelated trace records in both report and SQLite log sinks.
- Cover unknown and unsupported delta response events.

GitOrigin-RevId: 6d9121e093ddadf6834da394df544d9c09d8aeb9

codex-rs/Cargo.lock

@@ -3162,6 +3162,7 @@ dependencies = [
  "anyhow",
  "codex-login",
  "codex-protocol",
+ "log",
  "mime_guess",
  "pretty_assertions",
  "sentry",

codex-rs/codex-api/src/sse/responses.rs

@@ -467,9 +467,28 @@ pub fn process_responses_event(
                 }));
             }
         }
-        _ => {
+        "codex.response.metadata"
+        | "response.content_part.added"
+        | "response.content_part.done"
+        | "response.custom_tool_call_input.done"
+        | "response.function_call_arguments.delta"
+        | "response.function_call_arguments.done"
+        | "response.in_progress"
+        | "response.metadata"
+        | "response.output_text.done"
+        | "response.reasoning_summary_part.done"
+        | "responsesapi.websocket_timing" => {
             trace!("unhandled responses event: {}", event.kind);
         }
+        kind if kind.ends_with(".delta") => {
+            trace!("unhandled responses event: {kind}");
+        }
+        _ => {
+            debug!(
+                "unhandled responses event: {:?}",
+                event.kind.chars().take(128).collect::<String>()
+            );
+        }
     }
 
     Ok(None)
@@ -536,7 +555,13 @@ async fn process_sse_with_treatment(
         let event: ResponsesStreamEvent = match serde_json::from_str(&sse.data) {
             Ok(event) => event,
             Err(e) => {
-                debug!("Failed to parse SSE event: {e}, data: {}", &sse.data);
+                debug!(
+                    error_category = ?e.classify(),
+                    error_line = e.line(),
+                    error_column = e.column(),
+                    payload_bytes = sse.data.len(),
+                    "Failed to parse SSE event"
+                );
                 continue;
             }
         };
@@ -1203,7 +1228,27 @@ mod tests {
             },
             TestCase {
                 name: "unknown",
-                event: json!({"type": "response.new_tool_event"}),
+                event: json!({"type": "response.new_tool_event", "sequence_number": 1}),
+                expect_first: is_completed,
+                expected_len: 1,
+            },
+            TestCase {
+                name: "refusal_delta",
+                event: json!({
+                    "type": "response.refusal.delta",
+                    "delta": "no",
+                    "sequence_number": 1
+                }),
+                expect_first: is_completed,
+                expected_len: 1,
+            },
+            TestCase {
+                name: "mcp_call_arguments_delta",
+                event: json!({
+                    "type": "response.mcp_call_arguments.delta",
+                    "delta": "chunk",
+                    "sequence_number": 1
+                }),
                 expect_first: is_completed,
                 expected_len: 1,
             },

codex-rs/feedback/Cargo.toml

@@ -17,6 +17,7 @@ tracing = { workspace = true }
 tracing-subscriber = { workspace = true }
 
 [dev-dependencies]
+log = { workspace = true }
 pretty_assertions = { workspace = true }
 
 [lib]

codex-rs/feedback/src/lib.rs

@@ -194,7 +194,7 @@ impl CodexFeedback {
         }
     }
 
-    /// Returns a [`tracing_subscriber`] layer that captures full-fidelity logs into this feedback
+    /// Returns a [`tracing_subscriber`] layer that captures diagnostic logs into this feedback
     /// ring buffer.
     ///
     /// This is intended for initialization code so call sites don't have to duplicate the exact
@@ -208,11 +208,17 @@ impl CodexFeedback {
             .with_timer(tracing_subscriber::fmt::time::SystemTime)
             .with_ansi(false)
             .with_target(false)
-            // Capture everything, regardless of the caller's `RUST_LOG`, so feedback includes the
+            // Capture diagnostics independently of `RUST_LOG` without filling the feedback ring
-            // full trace when the user uploads a report.
+            // with high-volume request and response payloads.
             .with_filter(
                 Targets::new()
                     .with_default(Level::TRACE)
+                    .with_target("codex_http_client::transport", LevelFilter::DEBUG)
+                    .with_target("codex_api::sse", LevelFilter::DEBUG)
+                    // `tracing-log` checks legacy log records against their original
+                    // target before re-emitting them as `log`; tungstenite TRACE
+                    // includes full websocket frames and authenticated handshakes.
+                    .with_target("tungstenite", LevelFilter::DEBUG)
                     .with_target("codex_api::responses_websocket_timing", LevelFilter::OFF)
                     .with_target("codex_core::post_sampling_token_estimate", LevelFilter::OFF),
             )
@@ -721,18 +727,50 @@ mod tests {
     }
 
     #[test]
-    fn logger_layer_excludes_responses_websocket_timing_payloads() {
+    fn logger_layer_filters_noisy_trace_payloads() {
         let fb = CodexFeedback::new();
         let _guard = tracing_subscriber::registry()
+            // Keep another TRACE subscriber interested so bridged records are
+            // emitted; feedback must still reject them with its own filter.
+            .with(tracing_subscriber::fmt::layer().with_writer(std::io::sink))
             .with(fb.logger_layer())
             .set_default();
 
         tracing::trace!(target: "codex_api::responses_websocket_timing", payload = "secret");
-        tracing::trace!(target: "codex_feedback_test", "retained");
+        tracing::trace!(target: "codex_http_client::transport", "transport-trace");
+        tracing::trace!(target: "codex_api::sse", "sse-trace");
+        tracing::trace!(target: "codex_api::sse::responses", "nested-sse-trace");
+        tracing::debug!(target: "codex_http_client::transport", "transport-debug");
+        tracing::debug!(target: "codex_api::sse::responses", "sse-debug");
+        tracing::trace!(target: "codex_feedback_test", "unrelated-trace");
+        log::trace!(target: "codex_feedback_test", "unrelated-log-trace");
+        log::trace!(
+            target: "tungstenite::handshake::client",
+            "websocket-handshake-payload"
+        );
+        log::trace!(target: "tungstenite::protocol", "websocket-frame-payload");
+        log::debug!(target: "tungstenite::protocol", "websocket-debug");
 
         let logs = String::from_utf8(fb.snapshot(/*session_id*/ None).bytes).unwrap();
-        assert!(!logs.contains("secret"));
+        for excluded in [
-        assert!(logs.contains("retained"));
+            "secret",
+            "transport-trace",
+            "sse-trace",
+            "nested-sse-trace",
+            "websocket-handshake-payload",
+            "websocket-frame-payload",
+        ] {
+            assert!(!logs.contains(excluded));
+        }
+        for retained in [
+            "transport-debug",
+            "sse-debug",
+            "unrelated-trace",
+            "unrelated-log-trace",
+            "websocket-debug",
+        ] {
+            assert!(logs.contains(retained));
+        }
     }
 
     #[test]

codex-rs/state/src/log_db.rs

@@ -61,6 +61,10 @@ pub fn default_filter() -> Targets {
         .with_target("rmcp", LevelFilter::INFO)
         .with_target("codex_api::responses_websocket_timing", LevelFilter::OFF)
         .with_target("codex_core::post_sampling_token_estimate", LevelFilter::OFF)
+        // Full model request bodies and streamed response payloads overwhelm the
+        // SQLite log database, but remain available to explicit TRACE subscribers.
+        .with_target("codex_http_client::transport", LevelFilter::DEBUG)
+        .with_target("codex_api::sse", LevelFilter::DEBUG)
 }
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]

codex-rs/state/src/log_db_filter_tests.rs

@@ -10,6 +10,9 @@ use super::*;
 async fn sqlite_sink_drops_low_level_opentelemetry_sdk_logs() {
     let codex_home =
         std::env::temp_dir().join(format!("codex-state-log-db-filter-{}", Uuid::new_v4()));
+    let _cleanup = scopeguard::guard(codex_home.clone(), |codex_home| {
+        let _ = std::fs::remove_dir_all(codex_home);
+    });
     let runtime = StateRuntime::init(
         crate::SqliteConfig::new_for_testing(codex_home.as_path().abs()),
         "test-provider".to_string(),
@@ -35,6 +38,11 @@ async fn sqlite_sink_drops_low_level_opentelemetry_sdk_logs() {
         target: "codex_rmcp_client::oauth",
         "retained-codex-rmcp-client-info"
     );
+    tracing::trace!(target: "codex_http_client::transport", "dropped-request-body");
+    tracing::debug!(target: "codex_http_client::transport", "retained-request-diagnostic");
+    tracing::trace!(target: "codex_api::sse", "dropped-sse-parent");
+    tracing::trace!(target: "codex_api::sse::responses", "dropped-sse-payload");
+    tracing::debug!(target: "codex_api::sse::responses", "retained-sse-diagnostic");
     tracing::trace!(target: "codex_state", "retained-trace");
     tracing::trace!(
         target: "codex_api::responses_websocket_timing",
@@ -65,9 +73,17 @@ async fn sqlite_sink_drops_low_level_opentelemetry_sdk_logs() {
                 "codex_rmcp_client::oauth",
                 Some("retained-codex-rmcp-client-info")
             ),
+            (
+                "DEBUG",
+                "codex_http_client::transport",
+                Some("retained-request-diagnostic")
+            ),
+            (
+                "DEBUG",
+                "codex_api::sse::responses",
+                Some("retained-sse-diagnostic")
+            ),
             ("TRACE", "codex_state", Some("retained-trace")),
         ]
     );
-
-    let _ = tokio::fs::remove_dir_all(codex_home).await;
 }