1 files changed, 7 insertions, 1 deletions
diff --git a/auction.go b/auction.go
index aeff7b3..78b9af6 100644
--- a/auction.go
+++ b/auction.go
@@ -35,8 +35,14 @@ type SignedDesciption struct {
 	SellerSignature string
 }
 
+// Auction is the simple interface for the engine
+type Auction interface {
+	Join(bidder Bidder)
+	Received(msg []byte) error
+}
+
 // Bidder is the interface that the Auction engine uses to communicate
 type Bidder interface {
 	Result()
-	Send(msg []byte, sig []byte)
+	Send(msg []byte, sig []byte) error
 }