✨ feat: emit app_startup.duration_ms alongside the seconds value (0.1.18)

CHANGELOG.md

@@ -7,6 +7,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.1.18] - 2026-09-18
+
+### Added
+
+- **`app_startup.duration_ms`** on every `app_startup` span (native cold and
+  warm, web cold and bfcache warm), next to the seconds-valued
+  `app_startup.duration`. The unsuffixed key gave no unit and produced the same
+  1000x display bug `anr.duration` did (fixed in 0.1.17 by renaming). Unlike
+  ANR, the seconds key is *kept*: RUM plugins before 0.1.34 read only
+  `app_startup.duration`, so dropping it would blank their startup panels.
+  Backends coalesce `app_startup.duration_ms` over `app_startup.duration * 1000`.
+
+### Fixed
+
+- `docs/configuration.md` claimed `enableStartupTracking` measured a "hot" start
+  and the 0.1.8 changelog entry named attribute keys that were never emitted.
+
 ## [0.1.17] - 2026-09-07
 
 Eight data-quality defects found validating browser RUM against live data. Four
@@ -634,8 +651,10 @@ slows trace/log export from 5s to 30s. All of it is opt-in-able — see below.
   the cold-start duration is measured from the OS process start, not from
   `Scout.initialize`. On background-to-active transitions, a `warm`
   `app_startup` span is emitted with duration measured to the next animation
-  frame. Both carry `app.startup.type` (`cold` | `warm`) and
-  `app.startup.duration_seconds`.
+  frame. Both carry `app_startup.type` (`cold` | `warm`) and
+  `app_startup.duration` (seconds). *(Corrected 2026-09-18: this entry
+  originally named the keys `app.startup.type` / `app.startup.duration_seconds`,
+  which were never what the SDK emitted.)*
 
 ## [0.1.6] - 2026-05-22
 

docs/configuration.md

@@ -171,7 +171,7 @@ Every auto-instrumentation can be turned off independently. All default to `true
 | `interactionEvents` | `['click','change','submit','input']` | Web only. Which DOM events auto-tap tracking listens to; the value lands on the span as `user_interaction.type`. See below. |
 | `enableErrorTracking` | `true` | `window.onerror`, `unhandledrejection`, native crashes via KSCrash + NDK signal handler + MetricKit + ApplicationExitInfo. Emits `error`, `app_crash`, `native_crash` spans. |
 | `enableLifecycleTracking` | `true` | App `foreground`/`background`/`paused`/`resumed`. Emits `app_paused` / `app_resumed` spans + `view.in_foreground_periods_json` on screen_view. |
-| `enableStartupTracking` | `true` | Cold/warm/hot start timing. Emits `app_startup` span. |
+| `enableStartupTracking` | `true` | Cold/warm start timing. Emits `app_startup` spans with `app_startup.type` (`cold` \| `warm`), `app_startup.duration` (seconds) and `app_startup.duration_ms` (milliseconds). Native cold start is measured from the OS process start; web cold start from navigation start to `loadEventEnd`. |
 | `enableConnectivityTracking` | `true` | Network type changes (`wifi` → `cellular`), connection quality. |
 | `enablePerformanceMetrics` | `true` | Memory and CPU samples. |
 | `enableLongTaskDetection` | `true` | JS long tasks > `longTaskThresholdMs`. Emits `long_task` span. |

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@base-14/scout-react",
-  "version": "0.1.17",
+  "version": "0.1.18",
   "description": "Zero-config OpenTelemetry RUM for React and React Native. Auto-captures clicks, navigation, errors, lifecycle, network, performance, and web vitals.",
   "license": "MIT",
   "author": "base-14",

src/core/attributes.test.ts

@@ -21,6 +21,7 @@ describe('attribute / span / metric name contract', () => {
     expect(ATTR.USER_INTERACTION_TARGET).toBe('user_interaction.target');
     expect(ATTR.APP_STARTUP_TYPE).toBe('app_startup.type');
     expect(ATTR.APP_STARTUP_DURATION).toBe('app_startup.duration');
+    expect(ATTR.APP_STARTUP_DURATION_MS).toBe('app_startup.duration_ms');
     expect(ATTR.LONG_TASK_DURATION).toBe('long_task.duration');
     expect(ATTR.ANR_DURATION_MS).toBe('anr.duration_ms');
     expect(ATTR.ANR_THRESHOLD_MS).toBe('anr.threshold_ms');

src/core/attributes.ts

@@ -82,6 +82,10 @@ export const ATTR = {
   DISPLAY_SCROLL_MAX_SCROLL_HEIGHT_TIME_MS: 'display.scroll.max_scroll_height_time_ms',
   APP_STARTUP_TYPE: 'app_startup.type',
   APP_STARTUP_DURATION: 'app_startup.duration',
+  /** Milliseconds. Pairs with the seconds-valued `app_startup.duration`
+   *  the way `anr.duration_ms` replaced `anr.duration`; readers coalesce
+   *  this over the legacy key while both exist. */
+  APP_STARTUP_DURATION_MS: 'app_startup.duration_ms',
   APP_STARTUP_METRIC: 'app_startup.metric',
   APP_STARTUP_IS_PREWARMED: 'app_startup.is_prewarmed',
   APP_STARTUP_HAS_SAVED_INSTANCE_STATE_BUNDLE:

src/core/scope.ts

@@ -1,2 +1,2 @@
 export const SCOPE_NAME = 'base14.scout.react';
-export const SCOPE_VERSION = '0.1.17';
+export const SCOPE_VERSION = '0.1.18';

src/native/index.ts

@@ -314,12 +314,13 @@ export const Scout = {
       nativeStartMs !== null
         ? (Date.now() - nativeStartMs) / 1000
         : core.timeSinceAppStartMs() / 1000;
+    const fbcMs = Math.round(coldDurationSec * 1000);
     core.emitSpan(SPAN.APP_STARTUP, {
       [ATTR.APP_STARTUP_TYPE]: 'cold',
       [ATTR.APP_STARTUP_DURATION]: coldDurationSec,
+      [ATTR.APP_STARTUP_DURATION_MS]: fbcMs,
       ...core.commonAttributes(),
     });
-    const fbcMs = Math.round(coldDurationSec * 1000);
     core.emitSpan(SPAN.APP_VITAL, {
       [ATTR.VITAL_NAME]: 'fbc',
       [ATTR.VITAL_TYPE]: 'startup',

src/native/instrumentations/lifecycle.ts

@@ -55,6 +55,7 @@ export function installNativeLifecycleTracker(
             scout.emitSpan(SPAN.APP_STARTUP, {
               [ATTR.APP_STARTUP_TYPE]: 'warm',
               [ATTR.APP_STARTUP_DURATION]: durationMs / 1000,
+              [ATTR.APP_STARTUP_DURATION_MS]: Math.round(durationMs),
               ...scout.commonAttributes(),
             });
           } catch {}

src/web/instrumentations/startup.ts

@@ -29,6 +29,7 @@ export function installStartupTracker(scout: Scout): () => void {
       scout.emitSpan(SPAN.APP_STARTUP, {
         [ATTR.APP_STARTUP_TYPE]: 'cold',
         [ATTR.APP_STARTUP_DURATION]: duration,
+        [ATTR.APP_STARTUP_DURATION_MS]: Math.round(duration * 1000),
         [ATTR.BROWSER_NAV_DOM_COMPLETE_MS]: nav.domComplete,
         [ATTR.BROWSER_NAV_DOM_CONTENT_LOADED_MS]: nav.domContentLoadedEventEnd,
         [ATTR.BROWSER_NAV_DOM_INTERACTIVE_MS]: nav.domInteractive,
@@ -52,6 +53,7 @@ export function installStartupTracker(scout: Scout): () => void {
     scout.emitSpan(SPAN.APP_STARTUP, {
       [ATTR.APP_STARTUP_TYPE]: 'warm',
       [ATTR.APP_STARTUP_DURATION]: 0,
+      [ATTR.APP_STARTUP_DURATION_MS]: 0,
       ...scout.commonAttributes(),
     });
     scout.addBreadcrumb(BREADCRUMB_TYPE.STARTUP, 'warm start (bfcache)');