update prebid configuration and explanation in readme

Author: eiman-eltigani-ttd

web-integrations/prebid-integrations/client-side-deferred/README.md

@@ -109,6 +109,36 @@ Access at: http://prebid-deferred.sample-dev.com (requires hosts file configurat
 4. **Observe results** - Token appears in the status tables
 5. **Test opt-out** - Use `[email protected]` to see opt-out behavior
 
+## Clearing UID2 Identity (Logout)
+
+UID2 state lives in two places:
+- **Browser storage** (localStorage) - where the token is persisted
+- **Prebid's in-memory cache** - where Prebid holds the token during the session
+
+To fully clear UID2 and prevent future bid requests from using the token:
+
+```javascript
+// Step 1: Clear UID2 from browser storage
+localStorage.removeItem('__uid2_advertising_token');
+
+// Step 2: Page reload clears Prebid's in-memory cache
+location.reload();
+```
+
+### Why Page Reload?
+
+Prebid's UID2 module doesn't expose a method to clear just UID2 without affecting other user ID modules. The `mergeConfig()` API is additive—once UID2 is added to `userSync.userIds`, there's no built-in way to remove only that configuration. Page reload ensures Prebid reinitializes fresh with an empty localStorage.
+
+### Alternative: Using the UID2 JavaScript SDK
+
+If you're using the [UID2 JavaScript SDK](https://unifiedid.com/docs/sdks/sdk-ref-javascript) directly (not just Prebid's module), you can use:
+
+```javascript
+__uid2.disconnect();
+```
+
+This automatically clears both storage and in-memory state without page reload. However, this method is **not available** when using Prebid's UID2 module alone—Prebid uses an internal implementation that doesn't expose the full SDK globally.
+
 ## Documentation
 
 - [UID2 Client-Side Integration Guide for Prebid.js](https://unifiedid.com/docs/guides/integration-prebid-client-side)

web-integrations/prebid-integrations/client-side-deferred/entrypoint.sh

@@ -6,6 +6,7 @@ export SERVER_PUBLIC_KEY=${UID_CSTG_SERVER_PUBLIC_KEY:-"UID2-X-I-MFkwEwYHKoZIzj0
 export SUBSCRIPTION_ID=${UID_CSTG_SUBSCRIPTION_ID:-"DMr7uHxqLU"}
 export UID_STORAGE_KEY=${UID_STORAGE_KEY:-"__uid2_advertising_token"}
 export IDENTITY_NAME=${IDENTITY_NAME:-"UID2"}
+export IDENTITY_NAME_LOWER=$(echo "$IDENTITY_NAME" | tr '[:upper:]' '[:lower:]')
 export DOCS_BASE_URL=${DOCS_BASE_URL:-"https://unifiedid.com/docs"}
 
 # Copy static files

web-integrations/prebid-integrations/client-side-deferred/index.html

@@ -110,8 +110,12 @@
         // Use mergeConfig() to add UID configuration after page load
         pbjs.mergeConfig(uidConfig);
 
-        // Call refreshUserIds() to trigger token generation
-        await pbjs.refreshUserIds();
+        console.log(`[${identityName}] Config merged. Calling refreshUserIds for ${userIdName} only...`);
+        
+        // Call refreshUserIds() with submoduleNames to only refresh UID2/EUID specifically
+        await pbjs.refreshUserIds({ submoduleNames: [userIdName] });
+        
+        console.log(`[${identityName}] refreshUserIds complete. Current getUserIds():`, pbjs.getUserIds());
 
         uidConfigured = true;
 
@@ -121,8 +125,12 @@
       }
 
       function handleClearStorage() {
+        // Clear UID2 identity from browser storage
         localStorage.removeItem(storageKey);
-        uidConfigured = false;
+        
+        // Page reload is required to clear Prebid's in-memory cache.
+        // Unlike the UID2 SDK which has disconnect(), Prebid's UID2 module
+        // doesn't expose a method to clear just UID2 without affecting other ID modules.
         location.reload();
       }
 
@@ -247,11 +255,17 @@ <h3>📄 Initial Prebid Config (on page load)</h3>
 
         <!-- Instructions -->
         <div id="merge_instructions" class="merge-instructions">
-          <p><strong>What happens when you click:</strong></p>
+          <p><strong>What happens when you click "Configure":</strong></p>
           <ol>
             <li><code>pbjs.mergeConfig(uidConfig)</code> - Merges ${IDENTITY_NAME} user ID module configuration into the existing Prebid config without overwriting other settings. This allows adding ${IDENTITY_NAME} after the page has already loaded.</li>
-            <li><code>pbjs.refreshUserIds()</code> - Triggers Prebid to re-fetch all configured user IDs, including the newly added ${IDENTITY_NAME} module, which initiates token generation using the provided email and CSTG credentials.</li>
+            <li><code>pbjs.refreshUserIds({ submoduleNames: ['${IDENTITY_NAME_LOWER}'] })</code> - Triggers Prebid to re-fetch the ${IDENTITY_NAME} user ID specifically, which initiates token generation using the provided email and CSTG credentials.</li>
+          </ol>
+          <p><strong>What happens when you click "Clear":</strong></p>
+          <ol>
+            <li><code>localStorage.removeItem(storageKey)</code> - Clears the ${IDENTITY_NAME} identity from browser storage.</li>
+            <li><code>location.reload()</code> - Reloads the page to clear Prebid's in-memory cache, preventing future bid requests from using the old token.</li>
           </ol>
+          <p class="config-note"><strong>Why reload?</strong> ${IDENTITY_NAME} state lives in browser storage and Prebid's memory. Prebid only reads the token—it doesn't provide a method to clear just ${IDENTITY_NAME} without affecting other ID modules. Page reload ensures a clean state.</p>
         </div>
 
         <!-- UID Token Status Section -->