fix(server): avoid replaying stale Codex usage limits (#26331)

Author: Yash-Singh1

apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.ts

@@ -4304,7 +4304,7 @@ export const makeCodexAdapterV2 = Effect.fn("makeCodexAdapterV2")(function* (
 
         yield* client.handleServerNotification("account/rateLimits/updated", (payload) =>
           Effect.gen(function* () {
-            yield* Ref.update(rateLimitSnapshot, (previous) =>
+            const previous = yield* Ref.getAndUpdate(rateLimitSnapshot, (previous) =>
               mergeCodexRateLimits(previous, payload.rateLimits),
             );
             const resetAt = codexUsageLimitResetAt(yield* Ref.get(rateLimitSnapshot));
@@ -4324,7 +4324,7 @@ export const makeCodexAdapterV2 = Effect.fn("makeCodexAdapterV2")(function* (
                 turnItem: updated,
               });
             }
-            const update = codexRateLimitsToUpdate(payload.rateLimits);
+            const update = codexRateLimitsToUpdate(payload.rateLimits, previous);
             if (update && adapterOptions.onUsageLimits) {
               const checkedAt = DateTime.formatIso(yield* DateTime.now);
               yield* adapterOptions.onUsageLimits({ ...update, checkedAt });

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

@@ -128,6 +128,29 @@ describe("codexRateLimitsToLimits", () => {
 });
 
 describe("codexRateLimitsToUpdate", () => {
+  it("does not republish cached windows over a newer account probe", () => {
+    const cached = {
+      primary: { usedPercent: 0, resetsAt: 1_784_000_000, windowDurationMins: 300 },
+      secondary: { usedPercent: 20, resetsAt: 1_784_500_000, windowDurationMins: 10080 },
+    };
+    expect(codexRateLimitsToUpdate(cached)?.windows).toHaveLength(2);
+    expect(codexRateLimitsToUpdate(structuredClone(cached), cached)).toBeUndefined();
+
+    const changed = { ...cached, secondary: { ...cached.secondary, usedPercent: 21 } };
+    expect(codexRateLimitsToUpdate(changed, cached)?.windows.map((window) => window.id)).toEqual([
+      "secondary",
+    ]);
+    expect(codexRateLimitsToUpdate({ primary: cached.primary }, cached)).toBeUndefined();
+    expect(
+      codexRateLimitsToUpdate({ primary: { ...cached.primary, resetsAt: 1_784_001_000 } }, cached)
+        ?.windows,
+    ).toHaveLength(1);
+    expect(
+      codexRateLimitsToUpdate({ primary: { ...cached.primary, usedPercent: 76 } }, cached)
+        ?.windows[0]?.usedPercent,
+    ).toBe(76);
+  });
+
   it("carries only the windows the notification names", () => {
     expect(
       codexRateLimitsToUpdate({

apps/server/src/provider/codexUsageLimits.ts

@@ -135,8 +135,20 @@ export function codexRateLimitsToLimits(input: {
 
 export function codexRateLimitsToUpdate(
   snapshot: CodexRateLimitSnapshot,
+  previous?: CodexRateLimitSnapshot,
 ): ProviderUsageLimitsUpdate | undefined {
-  const windows = codexRateLimitsToWindows(snapshot);
+  const previousWindows = previous ? codexRateLimitsToWindows(previous) : [];
+  // Token ticks repeat session-cached limits that may predate an account probe or reset.
+  const windows = codexRateLimitsToWindows(snapshot).filter((window) => {
+    const existing = previousWindows.find((candidate) => candidate.id === window.id);
+    return (
+      !existing ||
+      existing.kind !== window.kind ||
+      existing.usedPercent !== window.usedPercent ||
+      existing.resetsAt !== window.resetsAt ||
+      existing.windowDurationMins !== window.windowDurationMins
+    );
+  });
   return windows.length > 0 ? { windows } : undefined;
 }