diff --git a/data/config.db b/data/config.db
index 62493c1..2d92fba 100644
--- a/data/config.db
+++ b/data/config.db
Binary files differ
diff --git a/internal/api/types.go b/internal/api/types.go
index efc45a3..d3ac75c 100644
--- a/internal/api/types.go
+++ b/internal/api/types.go
@@ -54,6 +54,7 @@
 type AppendFilterChainRequest struct {
 	ListenerName string `json:"listener_name"`
 	YAML         string `json:"yaml"`
+	Upsert       bool   `json:"upsert"`
 }
 
 // UpdateFilterChainRequest defines payload to append a filter chain to a given listener
diff --git a/internal/api_handlers.go b/internal/api_handlers.go
index f93157a..fe13508 100644
--- a/internal/api_handlers.go
+++ b/internal/api_handlers.go
@@ -311,7 +311,7 @@
 		http.Error(w, fmt.Sprintf("failed to load filter chain %v", err), http.StatusBadRequest)
 		return
 	}
-	if err := api.Manager.AppendFilterChainToListener(ctx, req.ListenerName, chain); err != nil {
+	if err := api.Manager.AppendFilterChainToListener(ctx, req.ListenerName, chain, req.Upsert); err != nil {
 		http.Error(w, fmt.Sprintf("failed to append filter chain: %v", err), http.StatusInternalServerError)
 		return
 	}
diff --git a/internal/pkg/snapshot/resource_crud.go b/internal/pkg/snapshot/resource_crud.go
index 6d878b5..288857b 100644
--- a/internal/pkg/snapshot/resource_crud.go
+++ b/internal/pkg/snapshot/resource_crud.go
@@ -22,7 +22,7 @@
 
 // AppendFilterChainToListener loads the current listener from the cache, appends the provided
 // FilterChain to its list of FilterChains, and updates the cache with the new snapshot.
-func (sm *SnapshotManager) AppendFilterChainToListener(ctx context.Context, listenerName string, newFilterChain *listenerv3.FilterChain) error {
+func (sm *SnapshotManager) AppendFilterChainToListener(ctx context.Context, listenerName string, newFilterChain *listenerv3.FilterChain, upsert bool) error {
 	log := internallog.LogFromContext(ctx)
 
 	// 1. Get the current Listener from the cache
@@ -36,9 +36,25 @@
 		return fmt.Errorf("resource '%s' is not a Listener type", listenerName)
 	}
 
-	// 2. Append the new FilterChain to the listener's list of filter chains.
-	listener.FilterChains = append(listener.FilterChains, newFilterChain)
-	log.Infof("Appended new filter chain (match: %v) to listener '%s'", newFilterChain.FilterChainMatch, listenerName)
+	replaced := false
+	for i, fc := range listener.FilterChains {
+		if fc.Name == newFilterChain.Name {
+			if !upsert {
+				return fmt.Errorf("filter chain with name '%s' already exists in listener '%s' and upsert is false", newFilterChain.Name, listenerName)
+			}
+			listener.FilterChains[i] = newFilterChain
+			replaced = true
+			log.Infof("Replaced new filter chain (match: %v) to listener '%s'", newFilterChain.FilterChainMatch, listenerName)
+			break
+		}
+	}
+
+	if !replaced {
+		// 2. Append the new FilterChain to the listener's list of filter chains.
+		listener.FilterChains = append(listener.FilterChains, newFilterChain)
+		log.Infof("Appended new filter chain (match: %v) to listener '%s'", newFilterChain.FilterChainMatch, listenerName)
+
+	}
 
 	// 3. Create a new snapshot with the modified listener (rest of logic remains similar)
 	snap, err := sm.Cache.GetSnapshot(sm.NodeID)
diff --git a/static/global.js b/static/global.js
index 4d57d2b..a46e4c5 100644
--- a/static/global.js
+++ b/static/global.js
@@ -272,7 +272,7 @@
 export async function submitNewFilterChain() {
     const listenerName = document.getElementById('add-fc-listener-name').value;
     const yamlData = document.getElementById('add-fc-yaml-input').value.trim();
-
+    const upsertCheckbox = document.getElementById('add-filter-chain-upsert-flag');
     if (!yamlData) {
         alert("Please paste the filter chain YAML configuration.");
         return;
@@ -285,6 +285,10 @@
 
     const payload = { listener_name: listenerName, yaml: yamlData };
 
+    if (upsertCheckbox && upsertCheckbox.checked) {
+            payload.upsert = true;
+    }
+
     try {
         const response = await fetch(`${API_BASE_URL}/append-filter-chain`, {
             method: 'POST',
@@ -297,7 +301,7 @@
             throw new Error(`HTTP Error ${response.status}: ${errorBody}`);
         }
 
-        alert(`Successfully appended new filter chain to '${listenerName}'.`);
+        alert(`Successfully update new filter chain to '${listenerName}'.`);
         
         document.getElementById('addFilterChainModal').style.display = 'none';
 
diff --git a/static/index.html b/static/index.html
index e11bc15..168c8ad 100644
--- a/static/index.html
+++ b/static/index.html
@@ -23,9 +23,10 @@
 
         <div class="toolbar">
             <div class="toolbar-left-group">
-                <button onclick="listClusters()">🔁 Reload Clusters</button>
-                <button onclick="listSecrets()">🔁 Reload Secrets</button>
-                <button onclick="listListeners()">🔁 Reload Listeners</button>
+                <!-- Not necessary to reload each section. -->
+                <button onclick="listClusters()" style="display: none;">🔁 Reload Clusters</button>
+                <button onclick="listSecrets()" style="display: none;">🔁 Reload Secrets</button>
+                <button onclick="listListeners()" style="display: none;">🔁 Reload Listeners</button>
                 <button onclick="loadAllData()">Refresh All Data 🌐</button>
             </div>
 
@@ -185,7 +186,12 @@
 
             <form id="add-filter-chain-form">
                 <input type="hidden" id="add-fc-listener-name" value="">
-
+                <div class="form-group checkbox-group" style="margin-bottom: 15px;">
+                    <input type="checkbox" id="add-filter-chain-upsert-flag" name="allowUpsert">
+                    <label for="add-filter-chain-upsert-flag">
+                        ✅ <b>Allow Upsert</b>: If a filter chain with the same name exists, update its configuration instead of failing.
+                    </label>
+                </div>
                 <label for="add-fc-yaml-input">Filter Chain YAML:</label>
                 <textarea id="add-fc-yaml-input" rows="15" placeholder="Paste YAML here..."></textarea>