sdk_ready metadata

Author: ZamoraEmmanuel

CHANGES.txt

@@ -1,6 +1,6 @@
 2.11.0 (January XX, 2026)
  - Added metadata to SDK_UPDATE events to indicate the type of update (FLAGS_UPDATE or SEGMENTS_UPDATE) and the names of updated flags or segments.
- - Added metadata to SDK_READY and SDK_READY_FROM_CACHE events, including `initialCacheLoad` (boolean indicating if SDK was loaded from cache) and `lastUpdateTimestamp` (Int64 milliseconds since epoch).
+ - Added metadata to SDK_READY and SDK_READY_FROM_CACHE events, including `initialCacheLoad` (boolean: `true` for fresh install/first app launch, `false` for warm cache/second app launch) and `lastUpdateTimestamp` (Int64 milliseconds since epoch).
 
 2.10.1 (December 18, 2025)
  - Bugfix - Handle `null` prerequisites properly.

src/readiness/__tests__/readinessManager.spec.ts

@@ -100,15 +100,13 @@ test('READINESS MANAGER / Ready from cache event should be fired once', (done) =
     counter++;
   });
 
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
   setTimeout(() => {
-    readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+    readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
   }, 0);
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
 
   setTimeout(() => {
     expect(counter).toBe(1); // should be called only once
@@ -366,19 +364,21 @@ test('READINESS MANAGER / SDK_UPDATE should forward metadata from segments', ()
 test('READINESS MANAGER / SDK_READY_FROM_CACHE should emit with metadata when cache is loaded', () => {
   const readinessManager = readinessManagerFactory(EventEmitter, settings);
 
+  const cacheTimestamp = Date.now() - 1000 * 60 * 60; // 1 hour ago
   let receivedMetadata: SdkReadyMetadata | undefined;
   readinessManager.gate.on(SDK_READY_FROM_CACHE, (meta: SdkReadyMetadata) => {
     receivedMetadata = meta;
   });
 
-  // Emit cache loaded event
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+  // Emit cache loaded event with timestamp
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, {
+    isCacheValid: true,
+    lastUpdateTimestamp: cacheTimestamp
+  });
 
   expect(receivedMetadata).toBeDefined();
-  expect(receivedMetadata!.initialCacheLoad).toBe(true);
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeGreaterThan(0);
-  // Allow small timing difference (up to 10ms)
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeLessThanOrEqual(Date.now() + 10);
+  expect(receivedMetadata!.initialCacheLoad).toBe(false);
+  expect(receivedMetadata!.lastUpdateTimestamp).toBe(cacheTimestamp);
 });
 
 test('READINESS MANAGER / SDK_READY_FROM_CACHE should emit with metadata when SDK becomes ready without cache', () => {
@@ -394,17 +394,16 @@ test('READINESS MANAGER / SDK_READY_FROM_CACHE should emit with metadata when SD
   readinessManager.segments.emit(SDK_SEGMENTS_ARRIVED);
 
   expect(receivedMetadata).toBeDefined();
-  expect(receivedMetadata!.initialCacheLoad).toBe(false);
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeGreaterThan(0);
-  // Allow small timing difference (up to 10ms)
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeLessThanOrEqual(Date.now() + 10);
+  expect(receivedMetadata!.initialCacheLoad).toBe(true);
+  expect(receivedMetadata!.lastUpdateTimestamp).toBeNull();
 });
 
 test('READINESS MANAGER / SDK_READY should emit with metadata when ready from cache', () => {
   const readinessManager = readinessManagerFactory(EventEmitter, settings);
 
-  // First emit cache loaded
-  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+  const cacheTimestamp = Date.now() - 1000 * 60 * 60; // 1 hour ago
+  // First emit cache loaded with timestamp
+  readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: cacheTimestamp });
 
   let receivedMetadata: SdkReadyMetadata | undefined;
   readinessManager.gate.on(SDK_READY, (meta: SdkReadyMetadata) => {
@@ -416,10 +415,8 @@ test('READINESS MANAGER / SDK_READY should emit with metadata when ready from ca
   readinessManager.segments.emit(SDK_SEGMENTS_ARRIVED);
 
   expect(receivedMetadata).toBeDefined();
-  expect(receivedMetadata!.initialCacheLoad).toBe(true); // Was ready from cache first
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeGreaterThan(0);
-  // Allow small timing difference (up to 10ms)
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeLessThanOrEqual(Date.now() + 10);
+  expect(receivedMetadata!.initialCacheLoad).toBe(false); // Was ready from cache first
+  expect(receivedMetadata!.lastUpdateTimestamp).toBe(cacheTimestamp);
 });
 
 test('READINESS MANAGER / SDK_READY should emit with metadata when ready without cache', () => {
@@ -435,8 +432,6 @@ test('READINESS MANAGER / SDK_READY should emit with metadata when ready without
   readinessManager.segments.emit(SDK_SEGMENTS_ARRIVED);
 
   expect(receivedMetadata).toBeDefined();
-  expect(receivedMetadata!.initialCacheLoad).toBe(false); // Was not ready from cache
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeGreaterThan(0);
-  // Allow small timing difference (up to 10ms)
-  expect(receivedMetadata!.lastUpdateTimestamp).toBeLessThanOrEqual(Date.now() + 10);
+  expect(receivedMetadata!.initialCacheLoad).toBe(true); // Was not ready from cache
+  expect(receivedMetadata!.lastUpdateTimestamp).toBeNull(); // No cache timestamp when fresh install
 });

src/readiness/__tests__/sdkReadinessManager.spec.ts

@@ -219,7 +219,7 @@ describe('SDK Readiness Manager - Promises', () => {
     const sdkReadinessManager = sdkReadinessManagerFactory(EventEmitter, fullSettings);
 
     // make the SDK ready from cache
-    sdkReadinessManager.readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED);
+    sdkReadinessManager.readinessManager.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
     expect(await sdkReadinessManager.sdkStatus.whenReadyFromCache()).toBe(false);
 
     // validate error log for SDK_READY_FROM_CACHE

src/readiness/readinessManager.ts

@@ -3,6 +3,7 @@ import { ISettings } from '../types';
 import SplitIO from '../../types/splitio';
 import { SDK_SPLITS_ARRIVED, SDK_SPLITS_CACHE_LOADED, SDK_SEGMENTS_ARRIVED, SDK_READY_TIMED_OUT, SDK_READY_FROM_CACHE, SDK_UPDATE, SDK_READY } from './constants';
 import { IReadinessEventEmitter, IReadinessManager, ISegmentsEventEmitter, ISplitsEventEmitter } from './types';
+import { CacheValidationMetadata } from '../storages/inLocalStorage/validateCache';
 
 function splitsEventEmitterFactory(EventEmitter: new () => SplitIO.IEventEmitter): ISplitsEventEmitter {
   const splitsEventEmitter = objectAssign(new EventEmitter(), {
@@ -55,6 +56,7 @@ export function readinessManagerFactory(
 
   // emit SDK_READY_FROM_CACHE
   let isReadyFromCache = false;
+  let cacheLastUpdateTimestamp: number | null = null;
   if (splits.splitsCacheLoaded) isReadyFromCache = true; // ready from cache, but doesn't emit SDK_READY_FROM_CACHE
   else splits.once(SDK_SPLITS_CACHE_LOADED, checkIsReadyFromCache);
 
@@ -84,17 +86,17 @@ export function readinessManagerFactory(
   splits.initCallbacks.push(__init);
   if (splits.hasInit) __init();
 
-  function checkIsReadyFromCache() {
+  function checkIsReadyFromCache(cacheMetadata: CacheValidationMetadata) {
     isReadyFromCache = true;
+    cacheLastUpdateTimestamp = cacheMetadata.lastUpdateTimestamp;
     // Don't emit SDK_READY_FROM_CACHE if SDK_READY has been emitted
     if (!isReady && !isDestroyed) {
       try {
         syncLastUpdate();
-        const metadata: SplitIO.SdkReadyMetadata = {
-          initialCacheLoad: true,
-          lastUpdateTimestamp: lastUpdate
-        };
-        gate.emit(SDK_READY_FROM_CACHE, metadata);
+        gate.emit(SDK_READY_FROM_CACHE, {
+          initialCacheLoad: !cacheMetadata.isCacheValid,
+          lastUpdateTimestamp: cacheLastUpdateTimestamp
+        });
       } catch (e) {
         // throws user callback exceptions in next tick
         setTimeout(() => { throw e; }, 0);
@@ -117,19 +119,18 @@ export function readinessManagerFactory(
         clearTimeout(readyTimeoutId);
         isReady = true;
         try {
-          syncLastUpdate();
           const wasReadyFromCache = isReadyFromCache;
           if (!isReadyFromCache) {
             isReadyFromCache = true;
-            const metadataFromCache: SplitIO.SdkReadyMetadata = {
-              initialCacheLoad: false,
-              lastUpdateTimestamp: lastUpdate
+            const metadataReadyFromCache: SplitIO.SdkReadyMetadata = {
+              initialCacheLoad: true,
+              lastUpdateTimestamp: null // No cache timestamp when fresh install
             };
-            gate.emit(SDK_READY_FROM_CACHE, metadataFromCache);
+            gate.emit(SDK_READY_FROM_CACHE, metadataReadyFromCache);
           }
           const metadataReady: SplitIO.SdkReadyMetadata = {
-            initialCacheLoad: wasReadyFromCache,
-            lastUpdateTimestamp: lastUpdate
+            initialCacheLoad: !wasReadyFromCache,
+            lastUpdateTimestamp: wasReadyFromCache ? cacheLastUpdateTimestamp : null
           };
           gate.emit(SDK_READY, metadataReady);
         } catch (e) {

src/sdkFactory/index.ts

@@ -54,18 +54,18 @@ export function sdkFactory(params: ISdkFactoryParams): SplitIO.ISDK | SplitIO.IA
         return;
       }
       readiness.splits.emit(SDK_SPLITS_ARRIVED);
-      readiness.segments.emit(SDK_SEGMENTS_ARRIVED);
+      readiness.segments.emit(SDK_SEGMENTS_ARRIVED, { isCacheValid: true, lastUpdateTimestamp: null });
     },
     onReadyFromCacheCb() {
-      readiness.splits.emit(SDK_SPLITS_CACHE_LOADED);
+      readiness.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
     }
   });
 
   const fallbackTreatmentsCalculator = new FallbackTreatmentsCalculator(settings.fallbackTreatments);
 
   if (initialRolloutPlan) {
     setRolloutPlan(log, initialRolloutPlan, storage as IStorageSync, key && getMatching(key));
-    if ((storage as IStorageSync).splits.getChangeNumber() > -1) readiness.splits.emit(SDK_SPLITS_CACHE_LOADED);
+    if ((storage as IStorageSync).splits.getChangeNumber() > -1) readiness.splits.emit(SDK_SPLITS_CACHE_LOADED, { isCacheValid: true, lastUpdateTimestamp: null });
   }
 
   const clients: Record<string, SplitIO.IBasicClient> = {};

src/storages/inLocalStorage/__tests__/validateCache.spec.ts

@@ -30,7 +30,9 @@ describe.each(storages)('validateCache', (storage) => {
   });
 
   test('if there is no cache, it should return false', async () => {
-    expect(await validateCache({}, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(false);
+    const result = await validateCache({}, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result.isCacheValid).toBe(false);
+    expect(result.lastUpdateTimestamp).toBeNull();
 
     expect(logSpy).not.toHaveBeenCalled();
 
@@ -45,11 +47,15 @@ describe.each(storages)('validateCache', (storage) => {
   });
 
   test('if there is cache and it must not be cleared, it should return true', async () => {
+    const lastUpdateTimestamp = Date.now() - 1000 * 60 * 60; // 1 hour ago
     storage.setItem(keys.buildSplitsTillKey(), '1');
     storage.setItem(keys.buildHashKey(), FULL_SETTINGS_HASH);
+    storage.setItem(keys.buildLastUpdatedKey(), lastUpdateTimestamp + '');
     await storage.save && storage.save();
 
-    expect(await validateCache({}, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(true);
+    const result = await validateCache({}, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result.isCacheValid).toBe(true);
+    expect(result.lastUpdateTimestamp).toBe(lastUpdateTimestamp);
 
     expect(logSpy).not.toHaveBeenCalled();
 
@@ -69,7 +75,9 @@ describe.each(storages)('validateCache', (storage) => {
     storage.setItem(keys.buildLastUpdatedKey(), Date.now() - 1000 * 60 * 60 * 24 * 2 + ''); // 2 days ago
     await storage.save && storage.save();
 
-    expect(await validateCache({ expirationDays: 1 }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(false);
+    const result = await validateCache({ expirationDays: 1 }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result.isCacheValid).toBe(false);
+    expect(result.lastUpdateTimestamp).toBeNull();
 
     expect(logSpy).toHaveBeenCalledWith('storage:localstorage: Cache expired more than 1 days ago. Cleaning up cache');
 
@@ -87,7 +95,9 @@ describe.each(storages)('validateCache', (storage) => {
     storage.setItem(keys.buildHashKey(), FULL_SETTINGS_HASH);
     await storage.save && storage.save();
 
-    expect(await validateCache({}, storage, { ...fullSettings, core: { ...fullSettings.core, authorizationKey: 'another-sdk-key' } }, keys, splits, rbSegments, segments, largeSegments)).toBe(false);
+    const result = await validateCache({}, storage, { ...fullSettings, core: { ...fullSettings.core, authorizationKey: 'another-sdk-key' } }, keys, splits, rbSegments, segments, largeSegments);
+    expect(result.isCacheValid).toBe(false);
+    expect(result.lastUpdateTimestamp).toBeNull();
 
     expect(logSpy).toHaveBeenCalledWith('storage:localstorage: SDK key, flags filter criteria, or flags spec version has changed. Cleaning up cache');
 
@@ -107,7 +117,9 @@ describe.each(storages)('validateCache', (storage) => {
     storage.setItem(keys.buildHashKey(), FULL_SETTINGS_HASH);
     await storage.save && storage.save();
 
-    expect(await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(false);
+    const result = await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result.isCacheValid).toBe(false);
+    expect(result.lastUpdateTimestamp).toBeNull();
 
     expect(logSpy).toHaveBeenCalledWith('storage:localstorage: clearOnInit was set and cache was not cleared in the last 24 hours. Cleaning up cache');
 
@@ -122,14 +134,20 @@ describe.each(storages)('validateCache', (storage) => {
 
     // If cache is cleared, it should not clear again until a day has passed
     logSpy.mockClear();
+    const lastUpdateTimestamp = Date.now() - 1000 * 60 * 60; // 1 hour ago
     storage.setItem(keys.buildSplitsTillKey(), '1');
-    expect(await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(true);
+    storage.setItem(keys.buildLastUpdatedKey(), lastUpdateTimestamp + '');
+    const result2 = await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result2.isCacheValid).toBe(true);
+    expect(result2.lastUpdateTimestamp).toBe(lastUpdateTimestamp);
     expect(logSpy).not.toHaveBeenCalled();
     expect(storage.getItem(keys.buildLastClear())).toBe(lastClear); // Last clear should not have changed
 
     // If a day has passed, it should clear again
     storage.setItem(keys.buildLastClear(), (Date.now() - 1000 * 60 * 60 * 24 - 1) + '');
-    expect(await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments)).toBe(false);
+    const result3 = await validateCache({ clearOnInit: true }, storage, fullSettings, keys, splits, rbSegments, segments, largeSegments);
+    expect(result3.isCacheValid).toBe(false);
+    expect(result3.lastUpdateTimestamp).toBeNull();
     expect(logSpy).toHaveBeenCalledWith('storage:localstorage: clearOnInit was set and cache was not cleared in the last 24 hours. Cleaning up cache');
     expect(splits.clear).toHaveBeenCalledTimes(2);
     expect(rbSegments.clear).toHaveBeenCalledTimes(2);

src/storages/inLocalStorage/index.ts

@@ -14,7 +14,7 @@ import { STORAGE_LOCALSTORAGE } from '../../utils/constants';
 import { shouldRecordTelemetry, TelemetryCacheInMemory } from '../inMemory/TelemetryCacheInMemory';
 import { UniqueKeysCacheInMemoryCS } from '../inMemory/UniqueKeysCacheInMemoryCS';
 import { getMatching } from '../../utils/key';
-import { validateCache } from './validateCache';
+import { validateCache, CacheValidationMetadata } from './validateCache';
 import { ILogger } from '../../logger/types';
 import SplitIO from '../../../types/splitio';
 import { storageAdapter } from './storageAdapter';
@@ -54,7 +54,7 @@ export function InLocalStorage(options: SplitIO.InLocalStorageOptions = {}): ISt
     const rbSegments = new RBSegmentsCacheInLocal(settings, keys, storage);
     const segments = new MySegmentsCacheInLocal(log, keys, storage);
     const largeSegments = new MySegmentsCacheInLocal(log, myLargeSegmentsKeyBuilder(prefix, matchingKey), storage);
-    let validateCachePromise: Promise<boolean> | undefined;
+    let validateCachePromise: Promise<CacheValidationMetadata> | undefined;
 
     return {
       splits,
@@ -68,7 +68,10 @@ export function InLocalStorage(options: SplitIO.InLocalStorageOptions = {}): ISt
       uniqueKeys: new UniqueKeysCacheInMemoryCS(),
 
       validateCache() {
-        return validateCachePromise || (validateCachePromise = validateCache(options, storage, settings, keys, splits, rbSegments, segments, largeSegments));
+        if (!validateCachePromise) {
+          validateCachePromise = validateCache(options, storage, settings, keys, splits, rbSegments, segments, largeSegments);
+        }
+        return validateCachePromise;
       },
 
       save() {