looprpc: expose server message to clients

client.go

@@ -382,6 +382,7 @@ func (s *Client) LoopOut(globalCtx context.Context,
 	return &LoopOutSwapInfo{
 		SwapHash:         swap.hash,
 		HtlcAddressP2WSH: swap.htlc.Address,
+		ServerMessage:    initResult.serverMessage,
 	}, nil
 }
 
@@ -500,6 +501,7 @@ func (s *Client) LoopIn(globalCtx context.Context,
 		SwapHash:          swap.hash,
 		HtlcAddressP2WSH:  swap.htlcP2WSH.Address,
 		HtlcAddressNP2WSH: swap.htlcNP2WSH.Address,
+		ServerMessage:     initResult.serverMessage,
 	}
 	return swapInfo, nil
 }

cmd/loop/loopin.go

@@ -157,6 +157,9 @@ func loopIn(ctx *cli.Context) error {
 		fmt.Printf("HTLC address (NP2WSH): %v\n", resp.HtlcAddressNp2Wsh)
 	}
 	fmt.Printf("HTLC address (P2WSH): %v\n", resp.HtlcAddressP2Wsh)
+	if resp.ServerMessage != "" {
+		fmt.Printf("Server message: %v\n", resp.ServerMessage)
+	}
 	fmt.Println()
 	fmt.Printf("Run `loop monitor` to monitor progress.\n")
 

cmd/loop/loopout.go

@@ -180,8 +180,11 @@ func loopOut(ctx *cli.Context) error {
 	}
 
 	fmt.Printf("Swap initiated\n")
-	fmt.Printf("ID:           %v\n", resp.Id)
-	fmt.Printf("HTLC address: %v\n", resp.HtlcAddress)
+	fmt.Printf("ID:             %v\n", resp.Id)
+	fmt.Printf("HTLC address:   %v\n", resp.HtlcAddress)
+	if resp.ServerMessage != "" {
+		fmt.Printf("Server message: %v\n", resp.ServerMessage)
+	}
 	fmt.Println()
 	fmt.Printf("Run `loop monitor` to monitor progress.\n")
 

interface.go

@@ -248,6 +248,10 @@ type LoopInSwapInfo struct { // nolint
 	// HtlcAddressNP2WSH contains the nested segwit swap htlc address,
 	// where the loop-in funds may be paid.
 	HtlcAddressNP2WSH btcutil.Address
+
+	// ServerMessages is the human-readable message received from the loop
+	// server.
+	ServerMessage string
 }
 
 // LoopOutSwapInfo contains essential information of a loop-out swap after the
@@ -259,6 +263,10 @@ type LoopOutSwapInfo struct { // nolint:golint
 	// HtlcAddressP2WSH contains the native segwit swap htlc address that
 	// the server will publish to.
 	HtlcAddressP2WSH btcutil.Address
+
+	// ServerMessages is the human-readable message received from the loop
+	// server.
+	ServerMessage string
 }
 
 // SwapInfoKit contains common swap info fields.

loopd/swapclient_server.go

@@ -114,6 +114,7 @@ func (s *swapClientServer) LoopOut(ctx context.Context,
 		IdBytes:          info.SwapHash[:],
 		HtlcAddress:      info.HtlcAddressP2WSH.String(),
 		HtlcAddressP2Wsh: info.HtlcAddressP2WSH.String(),
+		ServerMessage:    info.ServerMessage,
 	}, nil
 }
 
@@ -456,6 +457,7 @@ func (s *swapClientServer) LoopIn(ctx context.Context,
 		Id:               swapInfo.SwapHash.String(),
 		IdBytes:          swapInfo.SwapHash[:],
 		HtlcAddressP2Wsh: swapInfo.HtlcAddressP2WSH.String(),
+		ServerMessage:    swapInfo.ServerMessage,
 	}
 
 	if req.ExternalHtlc {

loopin.go

@@ -65,7 +65,8 @@ type loopInSwap struct {
 
 // loopInInitResult contains information about a just-initiated loop in swap.
 type loopInInitResult struct {
-	swap *loopInSwap
+	swap          *loopInSwap
+	serverMessage string
 }
 
 // newLoopInSwap initiates a new loop in swap.
@@ -191,7 +192,8 @@ func newLoopInSwap(globalCtx context.Context, cfg *swapConfig,
 	}
 
 	return &loopInInitResult{
-		swap: swap,
+		swap:          swap,
+		serverMessage: swapResp.serverMessage,
 	}, nil
 }
 

loopout.go

@@ -75,7 +75,8 @@ type executeConfig struct {
 
 // loopOutInitResult contains information about a just-initiated loop out swap.
 type loopOutInitResult struct {
-	swap *loopOutSwap
+	swap          *loopOutSwap
+	serverMessage string
 }
 
 // newLoopOutSwap initiates a new swap with the server and returns a
@@ -186,7 +187,8 @@ func newLoopOutSwap(globalCtx context.Context, cfg *swapConfig,
 	}
 
 	return &loopOutInitResult{
-		swap: swap,
+		swap:          swap,
+		serverMessage: swapResp.serverMessage,
 	}, nil
 }
 

looprpc/client.proto

@@ -272,6 +272,9 @@ message SwapResponse {
     Used for both loop-in and loop-out.
     */
     string htlc_address_p2wsh = 5;
+
+    // A human-readable message received from the loop server.
+    string server_message = 6;
 }
 
 message MonitorRequest {

looprpc/client.swagger.json

@@ -524,6 +524,10 @@
         "htlc_address_p2wsh": {
           "type": "string",
           "description": "*\nThe native segwit address of the on-chain htlc.\nUsed for both loop-in and loop-out."
+        },
+        "server_message": {
+          "type": "string",
+          "description": "A human-readable message received from the loop server."
         }
       }
     },