diff --git a/db/src/main.go b/db/src/main.go
index 0d3fc93..8351b35 100644
--- a/db/src/main.go
+++ b/db/src/main.go
@@ -167,7 +167,7 @@ func main() {
 	// Initialize and start REST Gateway
 	restUsername := getEnv("REST_USERNAME", "user")
 	restPassword := getEnv("REST_PASSWORD", "password")
-	restGateway := rest.NewRestGateway(influxGateway, measurementName, restUsername, restPassword)
+	restGateway := rest.NewRestGateway(influxGateway, mapping, measurementName, restUsername, restPassword)
 
 	port := getEnv("REST_PORT", "8080")
 
diff --git a/db/src/mapping.go b/db/src/mapping.go
index 2e0ceac..e295d08 100644
--- a/db/src/mapping.go
+++ b/db/src/mapping.go
@@ -78,3 +78,16 @@ func (c *MappingConfig) GetRoom(nodeID string) (string, bool) {
 	room, ok := c.nodeToRoom[nodeID]
 	return room, ok
 }
+
+// Rooms returns the list of all room names defined in the mapping.
+func (c *MappingConfig) Rooms() []string {
+	seen := make(map[string]struct{})
+	for _, room := range c.nodeToRoom {
+		seen[room] = struct{}{}
+	}
+	rooms := make([]string, 0, len(seen))
+	for room := range seen {
+		rooms = append(rooms, room)
+	}
+	return rooms
+}
diff --git a/db/src/rest/rest.go b/db/src/rest/rest.go
index e2d35b8..cabcc82 100644
--- a/db/src/rest/rest.go
+++ b/db/src/rest/rest.go
@@ -6,6 +6,7 @@ import (
 	"gateway/influx"
 	"net/http"
 	"regexp"
+	"slices"
 
 	_ "gateway/docs"
 
@@ -15,17 +16,24 @@ import (
 	ginSwagger "github.com/swaggo/gin-swagger"
 )
 
+// RoomLister is an interface for getting the list of rooms from the mapping.
+type RoomLister interface {
+	Rooms() []string
+}
+
 type RestGateway struct {
 	influxGateway   *influx.InfluxGateway
+	mapping         RoomLister
 	engine          *gin.Engine
 	measurementName string
 	username        string
 	password        string
 }
 
-func NewRestGateway(influxGateway *influx.InfluxGateway, measurementName string, username, password string) *RestGateway {
+func NewRestGateway(influxGateway *influx.InfluxGateway, mapping RoomLister, measurementName string, username, password string) *RestGateway {
 	g := &RestGateway{
 		influxGateway:   influxGateway,
+		mapping:         mapping,
 		engine:          gin.Default(),
 		measurementName: measurementName,
 		username:        username,
@@ -82,29 +90,8 @@ func (g *RestGateway) Run(addr string) error {
 // @Security BasicAuth
 // @Router /rooms [get]
 func (g *RestGateway) getRooms(c *gin.Context) {
-	// Query unique rooms from the measurement
-	query := fmt.Sprintf(`SELECT DISTINCT("room") FROM "%s"`, g.measurementName)
-
-	// Using context.Background() as seen in working snippet
-	it, err := g.influxGateway.Query(context.Background(), query)
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-		return
-	}
-
-	var rooms []string
-	for it.Next() {
-		val := it.Value()
-		if room, ok := val["room"].(string); ok {
-			rooms = append(rooms, room)
-		}
-	}
-
-	if err := it.Err(); err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-		return
-	}
-
+	rooms := g.mapping.Rooms()
+	slices.Sort(rooms)
 	c.JSON(http.StatusOK, rooms)
 }