WIP

playground/nextjs/package.json

@@ -22,7 +22,7 @@
         "eslint-config-next": "13.1.6",
         "hls.js": "^1.5.15",
         "next": "13.5.6",
-        "posthog-js": "1.166.0",
+        "posthog-js": "1.178.0",
         "react": "18.2.0",
         "react-dom": "18.2.0",
         "typescript": "4.9.5"

playground/nextjs/src/posthog.ts

@@ -56,6 +56,7 @@ if (typeof window !== 'undefined') {
         person_profiles: PERSON_PROCESSING_MODE === 'never' ? 'identified_only' : PERSON_PROCESSING_MODE,
         persistence_name: `${process.env.NEXT_PUBLIC_POSTHOG_KEY}_nextjs`,
         ...configForConsent(),
+        __use_cookieless_server_hash: true,
     })
 
     // Help with debugging(window as any).posthog = posthog

src/posthog-core.ts

@@ -465,7 +465,7 @@ export class PostHog {
         // isUndefined doesn't provide typehint here so wouldn't reduce bundle as we'd need to assign
         // eslint-disable-next-line posthog-js/no-direct-undefined-check
         if (config.bootstrap?.distinctID !== undefined) {
-            const uuid = this.config.get_device_id(uuidv7())
+            const uuid = this._create_device_id()
             const deviceID = config.bootstrap?.isIdentifiedID ? uuid : config.bootstrap.distinctID
             this.persistence.set_property(USER_STATE, config.bootstrap?.isIdentifiedID ? 'identified' : 'anonymous')
             this.register({
@@ -499,9 +499,7 @@ export class PostHog {
             // There is no need to set the distinct id
             // or the device id if something was already stored
             // in the persistence
-            const uuid = this.config.__use_cookieless_server_hash
-                ? SENTINEL_COOKIELESS_SERVER_HASH
-                : this.config.get_device_id(uuidv7())
+            const uuid = this._create_device_id()
 
             this.register_once(
                 {
@@ -1518,7 +1516,9 @@ export class PostHog {
         this.sessionPersistence?.clear()
         this.persistence?.set_property(USER_STATE, 'anonymous')
         this.sessionManager?.resetSessionId()
-        const uuid = this.config.get_device_id(uuidv7())
+        const uuid = this.config.__use_cookieless_server_hash
+            ? SENTINEL_COOKIELESS_SERVER_HASH
+            : this.config.get_device_id(uuidv7())
         this.register_once(
             {
                 distinct_id: uuid,
@@ -2015,6 +2015,13 @@ export class PostHog {
         }
     }
 
+    private _create_device_id(): string {
+        if (this.config.__use_cookieless_server_hash) {
+            return SENTINEL_COOKIELESS_SERVER_HASH
+        }
+        return this.config.get_device_id(uuidv7())
+    }
+
     /**
      * Opt the user in to data capturing and cookies/localstorage for this PostHog instance
      * If the config.opt_out_persistence_by_default is set to false, the SDK persistence will be enabled.