Fix runtime review findings

clients/go/mxgateway/client.go

@@ -16,6 +16,7 @@ import (
 const (
 	defaultDialTimeout = 10 * time.Second
 	defaultCallTimeout = 30 * time.Second
+	defaultMaxGrpcMessageBytes = 16 * 1024 * 1024
 )
 
 // Client owns a gateway gRPC connection and exposes session-oriented helpers.
@@ -50,6 +51,10 @@ func Dial(ctx context.Context, opts Options) (*Client, error) {
 		grpc.WithTransportCredentials(transportCredentials),
 		grpc.WithUnaryInterceptor(unaryAuthInterceptor(opts.APIKey)),
 		grpc.WithStreamInterceptor(streamAuthInterceptor(opts.APIKey)),
+		grpc.WithDefaultCallOptions(
+			grpc.MaxCallRecvMsgSize(resolveMaxGrpcMessageBytes(opts)),
+			grpc.MaxCallSendMsgSize(resolveMaxGrpcMessageBytes(opts)),
+		),
 		grpc.WithBlock(),
 	}
 	dialOptions = append(dialOptions, opts.DialOptions...)
@@ -62,6 +67,13 @@ func Dial(ctx context.Context, opts Options) (*Client, error) {
 	return NewClient(conn, opts), nil
 }
 
+func resolveMaxGrpcMessageBytes(opts Options) int {
+	if opts.MaxGrpcMessageBytes > 0 {
+		return opts.MaxGrpcMessageBytes
+	}
+	return defaultMaxGrpcMessageBytes
+}
+
 // NewClient wraps an existing gRPC connection. The caller owns closing conn
 // unless it calls Close on the returned Client.
 func NewClient(conn *grpc.ClientConn, opts Options) *Client {