Keep API request metrics out of Statsig exports (#36840)

## What changed

- Treat `codex.api_request` and `codex.api_request.duration_ms` as runtime-only metrics for Statsig exporters, matching the existing tool-call metric behavior.
- Keep both metrics available through other OTLP exporters.

## Testing

- Extend the Statsig filtering test to cover both API request metrics.
- Verify the OTLP HTTP exporter still sends the API request count and duration.

GitOrigin-RevId: f0f800ade7979e4da72ae59641bf42aa8a3ebd5a

codex-rs/otel/src/metrics/config.rs

@@ -1,5 +1,7 @@
 use crate::config::OtelExporter;
 use crate::metrics::Result;
+use crate::metrics::names::API_CALL_COUNT_METRIC;
+use crate::metrics::names::API_CALL_DURATION_METRIC;
 use crate::metrics::names::TOOL_CALL_COUNT_METRIC;
 use crate::metrics::names::TOOL_CALL_DURATION_METRIC;
 use crate::metrics::validation::validate_tag_key;
@@ -8,7 +10,12 @@ use opentelemetry_sdk::metrics::InMemoryMetricExporter;
 use std::collections::BTreeMap;
 use std::time::Duration;
 
-const RUNTIME_ONLY_METRICS: &[&str] = &[TOOL_CALL_COUNT_METRIC, TOOL_CALL_DURATION_METRIC];
+const RUNTIME_ONLY_METRICS: &[&str] = &[
+    API_CALL_COUNT_METRIC,
+    API_CALL_DURATION_METRIC,
+    TOOL_CALL_COUNT_METRIC,
+    TOOL_CALL_DURATION_METRIC,
+];
 
 #[derive(Clone, Debug)]
 pub enum MetricsExporter {

codex-rs/otel/src/provider.rs

@@ -462,6 +462,8 @@ mod shutdown_tests;
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::metrics::API_CALL_COUNT_METRIC;
+    use crate::metrics::API_CALL_DURATION_METRIC;
     use crate::metrics::MetricsExporter;
     use crate::metrics::TOOL_CALL_COUNT_METRIC;
     use crate::metrics::TOOL_CALL_DURATION_METRIC;
@@ -544,6 +546,8 @@ mod tests {
         config.exporter = MetricsExporter::InMemory(exporter.clone());
         let metrics = MetricsClient::new(config)?;
 
+        metrics.counter(API_CALL_COUNT_METRIC, /*inc*/ 1, &[])?;
+        metrics.record_duration(API_CALL_DURATION_METRIC, Duration::from_millis(100), &[])?;
         metrics.counter(TOOL_CALL_COUNT_METRIC, /*inc*/ 1, &[])?;
         metrics.record_duration(TOOL_CALL_DURATION_METRIC, Duration::from_millis(25), &[])?;
         metrics.counter("codex.turns", /*inc*/ 1, &[])?;

codex-rs/otel/tests/suite/otlp_http_loopback.rs

@@ -186,6 +186,12 @@ fn otlp_http_exporter_sends_metrics_to_collector() -> Result<()> {
     ))?;
 
     metrics.counter("codex.turns", /*inc*/ 1, &[("source", "test")])?;
+    metrics.counter("codex.api_request", /*inc*/ 1, &[("status", "200")])?;
+    metrics.record_duration(
+        "codex.api_request.duration_ms",
+        Duration::from_millis(100),
+        &[("status", "200")],
+    )?;
     metrics.counter("codex.tool.call", /*inc*/ 1, &[("tool", "test")])?;
     metrics.record_duration(
         "codex.tool.call.duration_ms",
@@ -227,6 +233,16 @@ fn otlp_http_exporter_sends_metrics_to_collector() -> Result<()> {
         "expected gauge not found; body prefix: {}",
         &body.chars().take(2000).collect::<String>()
     );
+    assert!(
+        body.contains("\"codex.api_request\""),
+        "expected API-request counter not found; body prefix: {}",
+        &body.chars().take(2000).collect::<String>()
+    );
+    assert!(
+        body.contains("\"codex.api_request.duration_ms\""),
+        "expected API-request duration not found; body prefix: {}",
+        &body.chars().take(2000).collect::<String>()
+    );
     assert!(
         body.contains("\"codex.tool.call\""),
         "expected tool-call counter not found; body prefix: {}",