diff --git a/.gitignore b/.gitignore
index 5976ef3..4bc1c0d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 config.yml
 relay_metadata.json
 grain.exe
-/build
\ No newline at end of file
+/build
+/logs
\ No newline at end of file
diff --git a/server/db/queryMongo.go b/server/db/queryMongo.go
index 82583f6..ed3077a 100644
--- a/server/db/queryMongo.go
+++ b/server/db/queryMongo.go
@@ -13,11 +13,12 @@ import (
 // QueryEvents queries events from the MongoDB collection(s) based on filters
 func QueryEvents(filters []relay.Filter, client *mongo.Client, databaseName string) ([]relay.Event, error) {
 	var results []relay.Event
+	var combinedFilters []bson.M
 
+	// Build MongoDB filters for each relay.Filter
 	for _, filter := range filters {
 		filterBson := bson.M{}
 
-		// Construct the BSON query based on the filters
 		if len(filter.IDs) > 0 {
 			filterBson["id"] = bson.M{"$in": filter.IDs}
 		}
@@ -45,62 +46,70 @@ func QueryEvents(filters []relay.Filter, client *mongo.Client, databaseName stri
 			}
 		}
 
-		opts := options.Find().SetSort(bson.D{{Key: "created_at", Value: -1}})
+		combinedFilters = append(combinedFilters, filterBson)
+	}
+
+	// Combine all filter conditions using the $or operator
+	query := bson.M{}
+	if len(combinedFilters) > 0 {
+		query["$or"] = combinedFilters
+	}
+
+	opts := options.Find().SetSort(bson.D{{Key: "created_at", Value: -1}})
+
+	// Apply limit if set for initial query
+	for _, filter := range filters {
 		if filter.Limit != nil {
 			opts.SetLimit(int64(*filter.Limit))
 		}
+	}
 
-		// If no specific kinds are specified, query all collections in the database
-		if len(filter.Kinds) == 0 {
-			collections, err := client.Database(databaseName).ListCollectionNames(context.TODO(), bson.D{})
+	// If no specific kinds are specified, query all collections
+	if len(filters[0].Kinds) == 0 {
+		collections, err := client.Database(databaseName).ListCollectionNames(context.TODO(), bson.D{})
+		if err != nil {
+			return nil, fmt.Errorf("error listing collections: %v", err)
+		}
+
+		for _, collectionName := range collections {
+			collection := client.Database(databaseName).Collection(collectionName)
+			cursor, err := collection.Find(context.TODO(), query, opts)
 			if err != nil {
-				return nil, fmt.Errorf("error listing collections: %v", err)
+				return nil, fmt.Errorf("error querying collection %s: %v", collectionName, err)
 			}
+			defer cursor.Close(context.TODO())
 
-			for _, collectionName := range collections {
-				fmt.Printf("Querying collection: %s with query: %v\n", collectionName, filterBson)
-
-				collection := client.Database(databaseName).Collection(collectionName)
-				cursor, err := collection.Find(context.TODO(), filterBson, opts)
-				if err != nil {
-					return nil, fmt.Errorf("error querying collection %s: %v", collectionName, err)
-				}
-				defer cursor.Close(context.TODO())
-
-				for cursor.Next(context.TODO()) {
-					var event relay.Event
-					if err := cursor.Decode(&event); err != nil {
-						return nil, fmt.Errorf("error decoding event from collection %s: %v", collectionName, err)
-					}
-					results = append(results, event)
-				}
-				if err := cursor.Err(); err != nil {
-					return nil, fmt.Errorf("cursor error in collection %s: %v", collectionName, err)
+			for cursor.Next(context.TODO()) {
+				var event relay.Event
+				if err := cursor.Decode(&event); err != nil {
+					return nil, fmt.Errorf("error decoding event from collection %s: %v", collectionName, err)
 				}
+				results = append(results, event)
 			}
-		} else {
-			// Query specific collections based on kinds
-			for _, kind := range filter.Kinds {
-				collectionName := fmt.Sprintf("event-kind%d", kind)
-				fmt.Printf("Querying collection: %s with query: %v\n", collectionName, filterBson)
+			if err := cursor.Err(); err != nil {
+				return nil, fmt.Errorf("cursor error in collection %s: %v", collectionName, err)
+			}
+		}
+	} else {
+		// Query specific collections based on kinds
+		for _, kind := range filters[0].Kinds {
+			collectionName := fmt.Sprintf("event-kind%d", kind)
+			collection := client.Database(databaseName).Collection(collectionName)
+			cursor, err := collection.Find(context.TODO(), query, opts)
+			if err != nil {
+				return nil, fmt.Errorf("error querying collection %s: %v", collectionName, err)
+			}
+			defer cursor.Close(context.TODO())
 
-				collection := client.Database(databaseName).Collection(collectionName)
-				cursor, err := collection.Find(context.TODO(), filterBson, opts)
-				if err != nil {
-					return nil, fmt.Errorf("error querying collection %s: %v", collectionName, err)
-				}
-				defer cursor.Close(context.TODO())
-
-				for cursor.Next(context.TODO()) {
-					var event relay.Event
-					if err := cursor.Decode(&event); err != nil {
-						return nil, fmt.Errorf("error decoding event from collection %s: %v", collectionName, err)
-					}
-					results = append(results, event)
-				}
-				if err := cursor.Err(); err != nil {
-					return nil, fmt.Errorf("cursor error in collection %s: %v", collectionName, err)
+			for cursor.Next(context.TODO()) {
+				var event relay.Event
+				if err := cursor.Decode(&event); err != nil {
+					return nil, fmt.Errorf("error decoding event from collection %s: %v", collectionName, err)
 				}
+				results = append(results, event)
+			}
+			if err := cursor.Err(); err != nil {
+				return nil, fmt.Errorf("cursor error in collection %s: %v", collectionName, err)
 			}
 		}
 	}
diff --git a/server/handlers/req.go b/server/handlers/req.go
index eca958d..9b7b97b 100644
--- a/server/handlers/req.go
+++ b/server/handlers/req.go
@@ -49,99 +49,104 @@ func HandleReq(ws *websocket.Conn, message []interface{}, subscriptions map[stri
 	}
 }
 
+
 // processRequest handles the actual processing of each request
 func processRequest(ws *websocket.Conn, message []interface{}) {
-	if len(message) < 3 {
-		fmt.Println("Invalid REQ message format")
-		response.SendClosed(ws, "", "invalid: invalid REQ message format")
-		return
-	}
+    if len(message) < 3 {
+        fmt.Println("Invalid REQ message format")
+        response.SendClosed(ws, "", "invalid: invalid REQ message format")
+        return
+    }
 
-	subID, ok := message[1].(string)
-	if !ok {
-		fmt.Println("Invalid subscription ID format")
-		response.SendClosed(ws, "", "invalid: invalid subscription ID format")
-		return
-	}
+    subID, ok := message[1].(string)
+    if !ok || len(subID) == 0 || len(subID) > 64 {
+        fmt.Println("Invalid subscription ID format or length")
+        response.SendClosed(ws, "", "invalid: subscription ID must be between 1 and 64 characters long")
+        return
+    }
 
-	mu.Lock()
-	defer mu.Unlock()
+    mu.Lock()
+    defer mu.Unlock()
 
-	// Check the current number of subscriptions for the client
-	if len(subscriptions) >= config.GetConfig().Server.MaxSubscriptionsPerClient {
-		// Find and remove the oldest subscription (FIFO)
-		var oldestSubID string
-		for id := range subscriptions {
-			oldestSubID = id
-			break
-		}
-		delete(subscriptions, oldestSubID)
-		fmt.Println("Dropped oldest subscription:", oldestSubID)
-	}
+    // Remove oldest subscription if needed
+    if len(subscriptions) >= config.GetConfig().Server.MaxSubscriptionsPerClient {
+        var oldestSubID string
+        for id := range subscriptions {
+            oldestSubID = id
+            break
+        }
+        delete(subscriptions, oldestSubID)
+        fmt.Println("Dropped oldest subscription:", oldestSubID)
+    }
 
-	// Prepare filters based on the incoming message
-	filters := make([]relay.Filter, len(message)-2)
-	for i, filter := range message[2:] {
-		filterData, ok := filter.(map[string]interface{})
-		if !ok {
-			fmt.Println("Invalid filter format")
-			response.SendClosed(ws, subID, "invalid: invalid filter format")
-			return
-		}
+    // Parse and validate filters
+    filters := make([]relay.Filter, len(message)-2)
+    for i, filter := range message[2:] {
+        filterData, ok := filter.(map[string]interface{})
+        if !ok {
+            fmt.Println("Invalid filter format")
+            response.SendClosed(ws, subID, "invalid: invalid filter format")
+            return
+        }
 
-		var f relay.Filter
-		f.IDs = utils.ToStringArray(filterData["ids"])
-		f.Authors = utils.ToStringArray(filterData["authors"])
-		f.Kinds = utils.ToIntArray(filterData["kinds"])
-		f.Tags = utils.ToTagsMap(filterData["tags"])
-		f.Since = utils.ToTime(filterData["since"])
-		f.Until = utils.ToTime(filterData["until"])
-		f.Limit = utils.ToInt(filterData["limit"])
+        var f relay.Filter
+        f.IDs = utils.ToStringArray(filterData["ids"])
+        f.Authors = utils.ToStringArray(filterData["authors"])
+        f.Kinds = utils.ToIntArray(filterData["kinds"])
+        f.Tags = utils.ToTagsMap(filterData["tags"])
+        f.Since = utils.ToTime(filterData["since"])
+        f.Until = utils.ToTime(filterData["until"])
+        f.Limit = utils.ToInt(filterData["limit"])
 
-		filters[i] = f
-	}
+        filters[i] = f
+    }
 
-	// Add the new subscription or update the existing one
-	subscriptions[subID] = relay.Subscription{Filters: filters}
-	fmt.Printf("Subscription updated: %s with %d filters\n", subID, len(filters))
+    // Validate filters
+    if !utils.ValidateFilters(filters) {
+        fmt.Println("Invalid filters: hex values not valid")
+        response.SendClosed(ws, subID, "invalid: filters contain invalid hex values")
+        return
+    }
 
-	// Query the database with filters and send back the results
-	queriedEvents, err := db.QueryEvents(filters, db.GetClient(), "grain")
-	if err != nil {
-		fmt.Println("Error querying events:", err)
-		response.SendClosed(ws, subID, "error: could not query events")
-		return
-	}
+    // Add subscription
+    subscriptions[subID] = relay.Subscription{Filters: filters}
+    fmt.Printf("Subscription updated: %s with %d filters\n", subID, len(filters))
 
-	// Log the number of events retrieved
-	fmt.Printf("Retrieved %d events for subscription %s\n", len(queriedEvents), subID)
-	if len(queriedEvents) == 0 {
-		fmt.Printf("No matching events found for subscription %s\n", subID)
-	}
+    // Query the database with filters and send back the results
+    queriedEvents, err := db.QueryEvents(filters, db.GetClient(), "grain")
+    if err != nil {
+        fmt.Println("Error querying events:", err)
+        response.SendClosed(ws, subID, "error: could not query events")
+        return
+    }
 
-	// Send each event back to the client
-	for _, evt := range queriedEvents {
-		msg := []interface{}{"EVENT", subID, evt}
-		msgBytes, _ := json.Marshal(msg)
-		err = websocket.Message.Send(ws, string(msgBytes))
-		if err != nil {
-			fmt.Println("Error sending event:", err)
-			response.SendClosed(ws, subID, "error: could not send event")
-			return
-		}
-	}
+    fmt.Printf("Retrieved %d events for subscription %s\n", len(queriedEvents), subID)
+    if len(queriedEvents) == 0 {
+        fmt.Printf("No matching events found for subscription %s\n", subID)
+    }
 
-	// Indicate end of stored events
-	eoseMsg := []interface{}{"EOSE", subID}
-	eoseBytes, _ := json.Marshal(eoseMsg)
-	err = websocket.Message.Send(ws, string(eoseBytes))
-	if err != nil {
-		fmt.Println("Error sending EOSE:", err)
-		response.SendClosed(ws, subID, "error: could not send EOSE")
-		return
-	}
+    for _, evt := range queriedEvents {
+        msg := []interface{}{"EVENT", subID, evt}
+        msgBytes, _ := json.Marshal(msg)
+        err = websocket.Message.Send(ws, string(msgBytes))
+        if err != nil {
+            fmt.Println("Error sending event:", err)
+            response.SendClosed(ws, subID, "error: could not send event")
+            return
+        }
+    }
 
-	fmt.Println("Subscription handling completed, keeping connection open.")
+    // Send EOSE message
+    eoseMsg := []interface{}{"EOSE", subID}
+    eoseBytes, _ := json.Marshal(eoseMsg)
+    err = websocket.Message.Send(ws, string(eoseBytes))
+    if err != nil {
+        fmt.Println("Error sending EOSE:", err)
+        response.SendClosed(ws, subID, "error: could not send EOSE")
+        return
+    }
+
+    fmt.Println("Subscription handling completed, keeping connection open.")
 }
 
 // Initialize the worker pool when your server starts
diff --git a/server/utils/validateFilter.go b/server/utils/validateFilter.go
new file mode 100644
index 0000000..e406807
--- /dev/null
+++ b/server/utils/validateFilter.go
@@ -0,0 +1,38 @@
+package utils
+
+import (
+	relay "grain/server/types"
+	"regexp"
+)
+
+// isValidHex validates if the given string is a 64-character lowercase hex string
+func isValidHex(str string) bool {
+	return len(str) == 64 && regexp.MustCompile(`^[a-f0-9]{64}$`).MatchString(str)
+}
+
+// ValidateFilters ensures the IDs, Authors, and Tags follow the correct hex format
+func ValidateFilters(filters []relay.Filter) bool {
+	for _, f := range filters {
+		// Validate IDs
+		for _, id := range f.IDs {
+			if !isValidHex(id) {
+				return false
+			}
+		}
+		// Validate Authors
+		for _, author := range f.Authors {
+			if !isValidHex(author) {
+				return false
+			}
+		}
+		// Validate Tags
+		for _, tags := range f.Tags {
+			for _, tag := range tags {
+				if !isValidHex(tag) {
+					return false
+				}
+			}
+		}
+	}
+	return true
+}