From b4d35a46dba9f25cdb39eb496e26bdf1d23f6bfb Mon Sep 17 00:00:00 2001
From: Daniel Jackins <djackins@twilio.com>
Date: Tue, 8 Oct 2024 09:43:32 -0600
Subject: [PATCH] use sample rate

---
 packages/browser/src/browser/index.ts                | 9 +++++++++
 packages/signals/signals/src/core/signals/signals.ts | 6 ++++++
 packages/signals/signals/src/types/analytics-api.ts  | 5 +++++
 3 files changed, 20 insertions(+)

diff --git a/packages/browser/src/browser/index.ts b/packages/browser/src/browser/index.ts
index c9d1927ec..603f80a31 100644
--- a/packages/browser/src/browser/index.ts
+++ b/packages/browser/src/browser/index.ts
@@ -122,6 +122,15 @@ export interface CDNSettings {
         version: number
       }
     | {}
+  /**
+   * Settings for auto instrumentation
+   */
+  autoInstrumentationSettings?: {
+    /**
+     * A sample rate to determine what percentage of sessions should send signals, from [0,1]
+     */
+    sampleRate: number
+  }
 }
 
 export interface AnalyticsBrowserSettings {
diff --git a/packages/signals/signals/src/core/signals/signals.ts b/packages/signals/signals/src/core/signals/signals.ts
index 634210604..7409b2c3b 100644
--- a/packages/signals/signals/src/core/signals/signals.ts
+++ b/packages/signals/signals/src/core/signals/signals.ts
@@ -83,6 +83,12 @@ export class Signals implements ISignals {
    * - Registers custom signal generators.
    */
   async start(analytics: AnyAnalytics): Promise<void> {
+    if (
+      !analytics.settings.cdnSettings.autoInstrumentationSettings ||
+      Math.random() >
+        analytics.settings.cdnSettings.autoInstrumentationSettings.sampleRate
+    )
+      return
     const analyticsService = new AnalyticsService(analytics)
 
     this.globalSettings.update({
diff --git a/packages/signals/signals/src/types/analytics-api.ts b/packages/signals/signals/src/types/analytics-api.ts
index cc84982ce..9dcde28b4 100644
--- a/packages/signals/signals/src/types/analytics-api.ts
+++ b/packages/signals/signals/src/types/analytics-api.ts
@@ -9,6 +9,7 @@ export type EdgeFnCDNSettings = {
 }
 
 export interface CDNSettings {
+  autoInstrumentationSettings?: CDNSettingsAutoInstrumentation
   integrations: CDNSettingsIntegrations
   edgeFunction?: EdgeFnCDNSettings | { [key: string]: never }
 }
@@ -72,6 +73,10 @@ export interface CDNSettingsIntegrations {
   [integrationName: string]: { [key: string]: any }
 }
 
+export interface CDNSettingsAutoInstrumentation {
+  sampleRate: number
+}
+
 export type PluginType = 'before' | 'after' | 'destination'
 
 export interface Plugin<Analytics = AnyAnalytics, Ctx = Record<string, any>> {