diff --git a/backend/internal/controller/http/v1/soroban.go b/backend/internal/controller/http/v1/soroban.go
index aca524ad..d73723e0 100644
--- a/backend/internal/controller/http/v1/soroban.go
+++ b/backend/internal/controller/http/v1/soroban.go
@@ -61,10 +61,9 @@ func (r *sorobanRoutes) signTransaction(c *gin.Context) {
 
 		request.WalletPk = sponsor.Key.PublicKey
 	}
-
 	res, err := r.m.SendMessage(entity.SignChannel, entity.SignTransactionRequest{
-		PublicKey: request.WalletPk,
-		Envelope:  request.Envelope,
+		PublicKeys: []string{request.WalletPk},
+		Envelope:   request.Envelope,
 	})
 	if err != nil {
 		errorResponse(c, http.StatusInternalServerError, "messaging problems", err)
diff --git a/backend/internal/entity/message.go b/backend/internal/entity/message.go
index a4fb054b..eb3d44df 100644
--- a/backend/internal/entity/message.go
+++ b/backend/internal/entity/message.go
@@ -77,9 +77,9 @@ type (
 	}
 
 	SignTransactionRequest struct {
-		Id        int    `json:"id"`
-		Envelope  string `json:"envelope"`
-		PublicKey string `json:"publicKey"`
+		Id         int      `json:"id"`
+		Envelope   string   `json:"envelope"`
+		PublicKeys []string `json:"publicKeys"`
 	}
 
 	SorobanTransactionResponse struct {