diff --git a/coordinator/coordinatorproto/coordinator.pb.go b/coordinator/coordinatorproto/coordinator.pb.go
index 172ffe8a..d0785154 100644
--- a/coordinator/coordinatorproto/coordinator.pb.go
+++ b/coordinator/coordinatorproto/coordinator.pb.go
@@ -52,6 +52,7 @@ func (SpaceStatus) EnumDescriptor() ([]byte, []int) {
 
 type SpaceSignRequest struct {
 	SpaceId string `protobuf:"bytes,1,opt,name=spaceId,proto3" json:"spaceId,omitempty"`
+	Header  []byte `protobuf:"bytes,2,opt,name=header,proto3" json:"header,omitempty"`
 }
 
 func (m *SpaceSignRequest) Reset()         { *m = SpaceSignRequest{} }
@@ -94,6 +95,13 @@ func (m *SpaceSignRequest) GetSpaceId() string {
 	return ""
 }
 
+func (m *SpaceSignRequest) GetHeader() []byte {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
 type SpaceSignResponse struct {
 	Receipt *SpaceReceiptWithSignature `protobuf:"bytes,1,opt,name=receipt,proto3" json:"receipt,omitempty"`
 }
@@ -587,44 +595,45 @@ func init() {
 }
 
 var fileDescriptor_d94f6f99586adae2 = []byte{
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-	0xec, 0x04, 0x06, 0x00, 0x00,
+	// 593 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x84, 0x54, 0xcd, 0x6e, 0xd3, 0x40,
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+	0x18, 0x59, 0x85, 0x9b, 0x91, 0x55, 0xf8, 0x33, 0xb2, 0x0a, 0x1f, 0xf7, 0x96, 0x6d, 0xfd, 0xcb,
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+	0x00,
 }
 
 func (m *SpaceSignRequest) Marshal() (dAtA []byte, err error) {
@@ -647,6 +656,13 @@ func (m *SpaceSignRequest) MarshalToSizedBuffer(dAtA []byte) (int, error) {
 	_ = i
 	var l int
 	_ = l
+	if len(m.Header) > 0 {
+		i -= len(m.Header)
+		copy(dAtA[i:], m.Header)
+		i = encodeVarintCoordinator(dAtA, i, uint64(len(m.Header)))
+		i--
+		dAtA[i] = 0x12
+	}
 	if len(m.SpaceId) > 0 {
 		i -= len(m.SpaceId)
 		copy(dAtA[i:], m.SpaceId)
@@ -1001,6 +1017,10 @@ func (m *SpaceSignRequest) Size() (n int) {
 	if l > 0 {
 		n += 1 + l + sovCoordinator(uint64(l))
 	}
+	l = len(m.Header)
+	if l > 0 {
+		n += 1 + l + sovCoordinator(uint64(l))
+	}
 	return n
 }
 
@@ -1216,6 +1236,40 @@ func (m *SpaceSignRequest) Unmarshal(dAtA []byte) error {
 			}
 			m.SpaceId = string(dAtA[iNdEx:postIndex])
 			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowCoordinator
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthCoordinator
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex < 0 {
+				return ErrInvalidLengthCoordinator
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Header = append(m.Header[:0], dAtA[iNdEx:postIndex]...)
+			if m.Header == nil {
+				m.Header = []byte{}
+			}
+			iNdEx = postIndex
 		default:
 			iNdEx = preIndex
 			skippy, err := skipCoordinator(dAtA[iNdEx:])
diff --git a/coordinator/coordinatorproto/protos/coordinator.proto b/coordinator/coordinatorproto/protos/coordinator.proto
index 13267fd8..4343b143 100644
--- a/coordinator/coordinatorproto/protos/coordinator.proto
+++ b/coordinator/coordinatorproto/protos/coordinator.proto
@@ -22,6 +22,7 @@ service Coordinator {
 
 message SpaceSignRequest {
     string spaceId = 1;
+    bytes header = 2;
 }
 
 enum SpaceStatus {