Fix codex usage rate limit fallback

Author: lintowe

apps/server/src/provider/codexUsage.test.ts

@@ -277,6 +277,27 @@ describe("normalizeCodexUsageSnapshot", () => {
     expect(snapshot?.rateLimitReachedType).toBe("primary");
   });
 
+  it("does not fall back when the selected bucket explicitly has no rate limit reached", () => {
+    const snapshot = normalizeCodexUsageSnapshot({
+      providerInstanceId: instanceId,
+      source: "read",
+      payload: {
+        rateLimits: {
+          primary: { usedPercent: 50, windowDurationMins: 300 },
+          rateLimitReachedType: null,
+        },
+        rateLimitsByLimitId: {
+          FiveHourLimit: {
+            primary: { usedPercent: 100 },
+            rateLimitReachedType: "primary",
+          },
+        },
+      },
+    });
+
+    expect(snapshot?.rateLimitReachedType).toBeNull();
+  });
+
   it("uses Codex primary and secondary semantics when durations are unknown", () => {
     const snapshot = normalizeCodexUsageSnapshot({
       providerInstanceId: instanceId,

apps/server/src/provider/codexUsage.ts

@@ -192,6 +192,16 @@ function rateLimitReachedTypeFromBucketGroups(
   return null;
 }
 
+function rateLimitReachedTypeFromSelectedBucket(
+  bucket: RateLimitBucket | null,
+  fallback: () => string | null,
+): string | null {
+  if (bucket && "rateLimitReachedType" in bucket) {
+    return bucket.rateLimitReachedType ?? null;
+  }
+  return fallback();
+}
+
 export function normalizeCodexUsageSnapshot(input: {
   readonly providerInstanceId: ProviderInstanceId;
   readonly payload: RateLimitPayload;
@@ -220,12 +230,12 @@ export function normalizeCodexUsageSnapshot(input: {
     providerInstanceId: input.providerInstanceId,
     checkedAt: input.checkedAt ?? new Date().toISOString(),
     windows,
-    rateLimitReachedType:
-      bucket?.rateLimitReachedType ??
+    rateLimitReachedType: rateLimitReachedTypeFromSelectedBucket(bucket, () =>
       rateLimitReachedTypeFromBucketGroups(
         input.payload.rateLimitsByLimitId,
         input.payload.rateLimitsByName,
       ),
+    ),
     source: input.source,
   };
 }