From c1d974139d3e0d3ba27f20adf13409a8b30413d1 Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Sat, 26 Oct 2024 07:45:36 +0300
Subject: [PATCH 1/7] wip: cancellation message types and services

---
 .../cmp/services/cancellation/v1/accept.proto | 27 +++++++++++++
 .../cancellation/v1/accept_counter.proto      | 27 +++++++++++++
 .../cancellation/v1/cancel_proposal.proto     | 23 +++++++++++
 .../services/cancellation/v1/counter.proto    | 27 +++++++++++++
 .../services/cancellation/v1/initiate.proto   | 25 ++++++++++++
 .../cmp/services/cancellation/v1/reject.proto | 39 +++++++++++++++++++
 .../services/cancellation/v1/services.proto   | 30 ++++++++++++++
 7 files changed, 198 insertions(+)
 create mode 100644 proto/cmp/services/cancellation/v1/accept.proto
 create mode 100644 proto/cmp/services/cancellation/v1/accept_counter.proto
 create mode 100644 proto/cmp/services/cancellation/v1/cancel_proposal.proto
 create mode 100644 proto/cmp/services/cancellation/v1/counter.proto
 create mode 100644 proto/cmp/services/cancellation/v1/initiate.proto
 create mode 100644 proto/cmp/services/cancellation/v1/reject.proto
 create mode 100644 proto/cmp/services/cancellation/v1/services.proto

diff --git a/proto/cmp/services/cancellation/v1/accept.proto b/proto/cmp/services/cancellation/v1/accept.proto
new file mode 100644
index 0000000..ab7dee7
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/accept.proto
@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+import "cmp/types/v2/price.proto";
+
+// Request for cancellation acceptance
+message AcceptCancellationRequest {
+  // Request header
+  optional cmp.types.v1.RequestHeader header = 1;
+
+  // Cancellation token ID
+  optional uint64 token_id = 2;
+
+  // Refund amount to validate the acceptance on-chain
+  optional cmp.types.v2.Price refund_amount = 3;
+}
+
+// Response for cancellation acceptance
+message AcceptCancellationResponse {
+  // Response header
+  optional cmp.types.v1.ResponseHeader header = 1;
+
+  // Accept cancellation transaction ID
+  optional string transaction_id = 2;
+}
diff --git a/proto/cmp/services/cancellation/v1/accept_counter.proto b/proto/cmp/services/cancellation/v1/accept_counter.proto
new file mode 100644
index 0000000..f214b11
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/accept_counter.proto
@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+import "cmp/types/v2/price.proto";
+
+// Request for counter cancellation acceptance
+message AcceptCounterCancellationRequest {
+  // Request header
+  optional cmp.types.v1.RequestHeader header = 1;
+
+  // Cancellation token ID
+  optional uint64 token_id = 2;
+
+  // Refund amount to validate the acceptance on-chain
+  optional cmp.types.v2.Price refund_amount = 3;
+}
+
+// Response for counter cancellation acceptance
+message AcceptCounterCancellationResponse {
+  // Response header
+  optional cmp.types.v1.ResponseHeader header = 1;
+
+  // Accept counter cancellation transaction ID
+  optional string transaction_id = 2;
+}
diff --git a/proto/cmp/services/cancellation/v1/cancel_proposal.proto b/proto/cmp/services/cancellation/v1/cancel_proposal.proto
new file mode 100644
index 0000000..b1e932a
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/cancel_proposal.proto
@@ -0,0 +1,23 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+
+// Request for cancelling an active cancellation proposal
+message CancelCancellationRequest {
+  // Request header
+  optional cmp.types.v1.RequestHeader header = 1;
+
+  // Cancellation token ID
+  optional uint64 token_id = 2;
+}
+
+// Response for cancelling an active cancellation proposal
+message CancelCancellationResponse {
+  // Response header
+  optional cmp.types.v1.ResponseHeader header = 1;
+
+  // Accept cancellation transaction ID
+  optional string transaction_id = 2;
+}
diff --git a/proto/cmp/services/cancellation/v1/counter.proto b/proto/cmp/services/cancellation/v1/counter.proto
new file mode 100644
index 0000000..80bf030
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/counter.proto
@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+import "cmp/types/v2/price.proto";
+
+// Request for countering a cancellation
+message CounterCancellationRequest {
+  // Request header
+  optional cmp.types.v1.RequestHeader header = 1;
+
+  // Cancellation token ID
+  optional uint64 token_id = 2;
+
+  // Refund amount to counter the cancellation proposal with
+  optional cmp.types.v2.Price refund_amount = 3;
+}
+
+// Response for countering a cancellation
+message CounterCancellationResponse {
+  // Response header
+  optional cmp.types.v1.ResponseHeader header = 1;
+
+  // Counter cancellation transaction ID
+  optional string transaction_id = 2;
+}
diff --git a/proto/cmp/services/cancellation/v1/initiate.proto b/proto/cmp/services/cancellation/v1/initiate.proto
new file mode 100644
index 0000000..3e0a059
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/initiate.proto
@@ -0,0 +1,25 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+import "cmp/types/v2/price.proto";
+
+message InitiateCancellationRequest {
+  // The request header
+  cmp.types.v1.RequestHeader header = 1;
+
+  // The token id of the booking to be cancelled
+  uint64 token_id = 2;
+
+  // The amount to be refunded
+  cmp.types.v2.Price refund_amount = 3;
+}
+
+message InitiateCancellationResponse {
+  // The response header
+  cmp.types.v1.ResponseHeader header = 1;
+
+  // Transaction id for the initiate cancellation request
+  string transaction_id = 2;
+}
diff --git a/proto/cmp/services/cancellation/v1/reject.proto b/proto/cmp/services/cancellation/v1/reject.proto
new file mode 100644
index 0000000..cbf6a83
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/reject.proto
@@ -0,0 +1,39 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/types/v1/common.proto";
+
+// Request for cancellation rejection
+message RejectCancellationRequest {
+  // Request Header
+  cmp.types.v1.RequestHeader header = 1;
+
+  // Token ID to reject the cancellation for (Booking Token)
+  uint64 token_id = 2;
+
+  // Reason for rejection
+  cmp.services.cancellation.v1.CancellationRejectionReason reason = 3;
+}
+
+// Response for cancellation rejection
+message RejectCancellationResponse {
+  // Response Header
+  cmp.types.v1.ResponseHeader header = 1;
+
+  // Transaction id for the rejected cancellation
+  string transaction_id = 2;
+}
+
+enum CancellationRejectionReason {
+  CANCELLATION_REJECTION_REASON_UNSPECIFIED = 0;
+  CANCELLATION_REJECTION_REASON_TECHNICAL_ERROR = 1;
+  CANCELLATION_REJECTION_REASON_INVALID_SERVICE_OR_BOOKING_REFERENCE = 2;
+  CANCELLATION_REJECTION_REASON_BOOKING_IS_ALREADY_CANCELLED = 3;
+  CANCELLATION_REJECTION_REASON_SERVICE_HAS_STARTED_OR_HAS_BEEN_DELIVERED = 4;
+  CANCELLATION_REJECTION_REASON_CANCELLATION_WINDOW_EXPIRED = 5;
+  CANCELLATION_REJECTION_REASON_SERVICE_CANNOT_BE_CANCELLED_ONLINE = 6;
+  CANCELLATION_REJECTION_REASON_RATE_OR_FARE_CANNOT_BE_CANCELLED = 7;
+  CANCELLATION_REJECTION_REASON_ENTIRE_PACKAGE_MUST_BE_CANCELLED = 8; // Service forms part of a package, the entire package must be cancelled
+  CANCELLATION_REJECTION_REASON_REFUND_CURRENCY_NOT_SUPPORTED = 9;
+}
diff --git a/proto/cmp/services/cancellation/v1/services.proto b/proto/cmp/services/cancellation/v1/services.proto
new file mode 100644
index 0000000..3a19769
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/services.proto
@@ -0,0 +1,30 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/services/cancellation/v1/accept.proto";
+import "cmp/services/cancellation/v1/accept_counter.proto";
+import "cmp/services/cancellation/v1/cancel_proposal.proto";
+import "cmp/services/cancellation/v1/counter.proto";
+import "cmp/services/cancellation/v1/initiate.proto";
+import "cmp/services/cancellation/v1/reject.proto";
+
+service CancellationService {
+  // Initiate cancellation
+  rpc InitiateCancellation(InitiateCancellationRequest) returns (InitiateCancellationResponse) {}
+
+  // Accept cancellation
+  rpc AcceptCancellation(AcceptCancellationRequest) returns (AcceptCancellationResponse) {}
+
+  // Reject cancellation
+  rpc RejectCancellation(RejectCancellationRequest) returns (RejectCancellationResponse) {}
+
+  // Counter cancellation
+  rpc CounterCancellation(CounterCancellationRequest) returns (CounterCancellationResponse) {}
+
+  // Accept countered cancellation
+  rpc AcceptCounterCancellation(AcceptCounterCancellationRequest) returns (AcceptCounterCancellationResponse) {}
+
+  // Cancel cancellation proposal
+  rpc CancelCancellation(CancelCancellationRequest) returns (CancelCancellationResponse) {}
+}

From 8af270bf5952d096256e4bbc3a183121ced09e3b Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Sat, 26 Oct 2024 08:01:08 +0300
Subject: [PATCH 2/7] add diagram urls

---
 proto/cmp/services/cancellation/v1/accept.proto   | 4 ++++
 proto/cmp/services/cancellation/v1/services.proto | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/proto/cmp/services/cancellation/v1/accept.proto b/proto/cmp/services/cancellation/v1/accept.proto
index ab7dee7..eab5f54 100644
--- a/proto/cmp/services/cancellation/v1/accept.proto
+++ b/proto/cmp/services/cancellation/v1/accept.proto
@@ -6,6 +6,10 @@ import "cmp/types/v1/common.proto";
 import "cmp/types/v2/price.proto";
 
 // Request for cancellation acceptance
+//
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/accept.proto.dot.xs.svg)
+//
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/accept.proto.dot.svg)
 message AcceptCancellationRequest {
   // Request header
   optional cmp.types.v1.RequestHeader header = 1;
diff --git a/proto/cmp/services/cancellation/v1/services.proto b/proto/cmp/services/cancellation/v1/services.proto
index 3a19769..ed13c86 100644
--- a/proto/cmp/services/cancellation/v1/services.proto
+++ b/proto/cmp/services/cancellation/v1/services.proto
@@ -9,6 +9,11 @@ import "cmp/services/cancellation/v1/counter.proto";
 import "cmp/services/cancellation/v1/initiate.proto";
 import "cmp/services/cancellation/v1/reject.proto";
 
+// Cancellation service
+//
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/services.proto.dot.xs.svg)
+//
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/services.proto.dot.svg)
 service CancellationService {
   // Initiate cancellation
   rpc InitiateCancellation(InitiateCancellationRequest) returns (InitiateCancellationResponse) {}

From 7dc31dfa2069db48944e1b32f8a689c5dbfd6ca6 Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Mon, 28 Oct 2024 12:15:15 +0300
Subject: [PATCH 3/7] add notifications for cancellation events

---
 buf.yaml                                      |  1 +
 .../cmp/services/notification/v1/notify.proto |  5 ++
 .../cmp/services/notification/v2/notify.proto | 81 +++++++++++++++++++
 3 files changed, 87 insertions(+)
 create mode 100644 proto/cmp/services/notification/v2/notify.proto

diff --git a/buf.yaml b/buf.yaml
index 86367be..980b97e 100644
--- a/buf.yaml
+++ b/buf.yaml
@@ -8,6 +8,7 @@ lint:
   ignore_only:
     RPC_REQUEST_STANDARD_NAME:
       - proto/cmp/services/notification/v1/notify.proto
+      - proto/cmp/services/notification/v2/notify.proto
   rpc_allow_google_protobuf_empty_responses: true
 breaking:
   use:
diff --git a/proto/cmp/services/notification/v1/notify.proto b/proto/cmp/services/notification/v1/notify.proto
index 6b75a7c..817dff4 100644
--- a/proto/cmp/services/notification/v1/notify.proto
+++ b/proto/cmp/services/notification/v1/notify.proto
@@ -16,6 +16,11 @@ message TokenExpired {
   cmp.types.v1.UUID mint_id = 2;
 }
 
+// Notification service for different events that the partner should be notified about
+//
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.xs.svg)
+//
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.svg)
 service NotificationService {
   rpc TokenBoughtNotification(TokenBought) returns (google.protobuf.Empty);
   rpc TokenExpiredNotification(TokenExpired) returns (google.protobuf.Empty);
diff --git a/proto/cmp/services/notification/v2/notify.proto b/proto/cmp/services/notification/v2/notify.proto
new file mode 100644
index 0000000..3364dda
--- /dev/null
+++ b/proto/cmp/services/notification/v2/notify.proto
@@ -0,0 +1,81 @@
+syntax = "proto3";
+
+package cmp.services.notification.v2;
+
+import "cmp/services/cancellation/v1/reject.proto";
+import "cmp/types/v1/uuid.proto";
+import "google/protobuf/empty.proto";
+
+// Notification service for different events that the partner should be notified about
+//
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.xs.svg)
+//
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.svg)
+service NotificationService {
+  rpc TokenBoughtNotification(TokenBought) returns (google.protobuf.Empty);
+  rpc TokenExpiredNotification(TokenExpired) returns (google.protobuf.Empty);
+  rpc CancellationPendingNotification(CancellationPending) returns (google.protobuf.Empty);
+  rpc CancellationAcceptedNotification(CancellationAccepted) returns (google.protobuf.Empty);
+  rpc CancellationProposalAcceptedByTheOwnerNotification(CancellationProposalAcceptedByTheOwner) returns (google.protobuf.Empty);
+  rpc CancellationCounteredNotification(CancellationCountered) returns (google.protobuf.Empty);
+  rpc CancellationProposalCancelledNotification(CancellationProposalCancelled) returns (google.protobuf.Empty);
+  rpc CancellationRejectedNotification(CancellationRejected) returns (google.protobuf.Empty);
+}
+
+message TokenBought {
+  uint64 token_id = 1;
+  string tx_id = 2;
+  cmp.types.v1.UUID mint_id = 3;
+}
+
+message TokenExpired {
+  uint64 token_id = 1;
+  cmp.types.v1.UUID mint_id = 2;
+}
+
+// event CancellationPending(uint256 indexed tokenId, address indexed proposedBy, uint256 refundAmount);
+message CancellationPending {
+  uint64 token_id = 1;
+  string proposed_by = 2;
+  uint64 refund_amount = 3;
+  string tx_id = 4;
+}
+
+// event CancellationAccepted(uint256 indexed tokenId, address indexed acceptedBy, uint256 refundAmount);
+message CancellationAccepted {
+  uint64 token_id = 1;
+  string accepted_by = 2;
+  uint64 refund_amount = 3;
+  string tx_id = 4;
+}
+
+// event CancellationProposalAcceptedByTheOwner(uint256 indexed tokenId, address indexed acceptedBy, uint256 refundAmount);
+message CancellationProposalAcceptedByTheOwner {
+  uint64 token_id = 1;
+  string accepted_by = 2;
+  uint64 refund_amount = 3;
+  string tx_id = 4;
+}
+
+// event CancellationCountered(uint256 indexed tokenId, address indexed counteredBy, uint256 newRefundAmount);
+message CancellationCountered {
+  uint64 token_id = 1;
+  string countered_by = 2;
+  uint64 new_refund_amount = 3;
+  string tx_id = 4;
+}
+
+// event CancellationProposalCancelled(uint256 indexed tokenId, address indexed cancelledBy);
+message CancellationProposalCancelled {
+  uint64 token_id = 1;
+  string cancelled_by = 2;
+  string tx_id = 3;
+}
+
+// event CancellationRejected(uint256 indexed tokenId, address indexed rejectedBy, CancellationRejectionReason reason);
+message CancellationRejected {
+  uint64 token_id = 1;
+  string rejected_by = 2;
+  cmp.services.cancellation.v1.CancellationRejectionReason reason = 3;
+  string tx_id = 4;
+}

From 36eafd6b4ac66ef16c8709140d329693e7fdcfe5 Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Mon, 28 Oct 2024 12:26:01 +0300
Subject: [PATCH 4/7] fix notification v1 diagram url

---
 proto/cmp/services/notification/v1/notify.proto | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/proto/cmp/services/notification/v1/notify.proto b/proto/cmp/services/notification/v1/notify.proto
index 817dff4..27045c0 100644
--- a/proto/cmp/services/notification/v1/notify.proto
+++ b/proto/cmp/services/notification/v1/notify.proto
@@ -18,9 +18,9 @@ message TokenExpired {
 
 // Notification service for different events that the partner should be notified about
 //
-// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.xs.svg)
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v1/notify.proto.dot.xs.svg)
 //
-// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v2/notify.proto.dot.svg)
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/notification/v1/notify.proto.dot.svg)
 service NotificationService {
   rpc TokenBoughtNotification(TokenBought) returns (google.protobuf.Empty);
   rpc TokenExpiredNotification(TokenExpired) returns (google.protobuf.Empty);

From c4dd8d4bc721f1e5fad37f89357c3fbbab5db566 Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Thu, 31 Oct 2024 02:23:14 +0300
Subject: [PATCH 5/7] add check cancellation service and types

---
 .../cmp/services/cancellation/v1/accept.proto | 10 ++--
 .../cancellation/v1/accept_counter.proto      | 10 ++--
 .../cancellation/v1/cancel_proposal.proto     |  8 +--
 .../cmp/services/cancellation/v1/check.proto  | 58 +++++++++++++++++++
 .../services/cancellation/v1/counter.proto    | 10 ++--
 5 files changed, 77 insertions(+), 19 deletions(-)
 create mode 100644 proto/cmp/services/cancellation/v1/check.proto

diff --git a/proto/cmp/services/cancellation/v1/accept.proto b/proto/cmp/services/cancellation/v1/accept.proto
index eab5f54..8e6488a 100644
--- a/proto/cmp/services/cancellation/v1/accept.proto
+++ b/proto/cmp/services/cancellation/v1/accept.proto
@@ -12,20 +12,20 @@ import "cmp/types/v2/price.proto";
 // [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/accept.proto.dot.svg)
 message AcceptCancellationRequest {
   // Request header
-  optional cmp.types.v1.RequestHeader header = 1;
+  cmp.types.v1.RequestHeader header = 1;
 
   // Cancellation token ID
-  optional uint64 token_id = 2;
+  uint64 token_id = 2;
 
   // Refund amount to validate the acceptance on-chain
-  optional cmp.types.v2.Price refund_amount = 3;
+  cmp.types.v2.Price refund_amount = 3;
 }
 
 // Response for cancellation acceptance
 message AcceptCancellationResponse {
   // Response header
-  optional cmp.types.v1.ResponseHeader header = 1;
+  cmp.types.v1.ResponseHeader header = 1;
 
   // Accept cancellation transaction ID
-  optional string transaction_id = 2;
+  string transaction_id = 2;
 }
diff --git a/proto/cmp/services/cancellation/v1/accept_counter.proto b/proto/cmp/services/cancellation/v1/accept_counter.proto
index f214b11..9464a78 100644
--- a/proto/cmp/services/cancellation/v1/accept_counter.proto
+++ b/proto/cmp/services/cancellation/v1/accept_counter.proto
@@ -8,20 +8,20 @@ import "cmp/types/v2/price.proto";
 // Request for counter cancellation acceptance
 message AcceptCounterCancellationRequest {
   // Request header
-  optional cmp.types.v1.RequestHeader header = 1;
+  cmp.types.v1.RequestHeader header = 1;
 
   // Cancellation token ID
-  optional uint64 token_id = 2;
+  uint64 token_id = 2;
 
   // Refund amount to validate the acceptance on-chain
-  optional cmp.types.v2.Price refund_amount = 3;
+  cmp.types.v2.Price refund_amount = 3;
 }
 
 // Response for counter cancellation acceptance
 message AcceptCounterCancellationResponse {
   // Response header
-  optional cmp.types.v1.ResponseHeader header = 1;
+  cmp.types.v1.ResponseHeader header = 1;
 
   // Accept counter cancellation transaction ID
-  optional string transaction_id = 2;
+  string transaction_id = 2;
 }
diff --git a/proto/cmp/services/cancellation/v1/cancel_proposal.proto b/proto/cmp/services/cancellation/v1/cancel_proposal.proto
index b1e932a..8ca81a2 100644
--- a/proto/cmp/services/cancellation/v1/cancel_proposal.proto
+++ b/proto/cmp/services/cancellation/v1/cancel_proposal.proto
@@ -7,17 +7,17 @@ import "cmp/types/v1/common.proto";
 // Request for cancelling an active cancellation proposal
 message CancelCancellationRequest {
   // Request header
-  optional cmp.types.v1.RequestHeader header = 1;
+  cmp.types.v1.RequestHeader header = 1;
 
   // Cancellation token ID
-  optional uint64 token_id = 2;
+  uint64 token_id = 2;
 }
 
 // Response for cancelling an active cancellation proposal
 message CancelCancellationResponse {
   // Response header
-  optional cmp.types.v1.ResponseHeader header = 1;
+  cmp.types.v1.ResponseHeader header = 1;
 
   // Accept cancellation transaction ID
-  optional string transaction_id = 2;
+  string transaction_id = 2;
 }
diff --git a/proto/cmp/services/cancellation/v1/check.proto b/proto/cmp/services/cancellation/v1/check.proto
new file mode 100644
index 0000000..ca86f9e
--- /dev/null
+++ b/proto/cmp/services/cancellation/v1/check.proto
@@ -0,0 +1,58 @@
+syntax = "proto3";
+
+package cmp.services.cancellation.v1;
+
+import "cmp/services/cancellation/v1/reject.proto";
+import "cmp/types/v1/common.proto";
+import "cmp/types/v2/price.proto";
+import "google/protobuf/timestamp.proto";
+
+// Service for checking cancellation
+//
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.dot.xs.svg)
+//
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.dot.svg)
+service CheckCancellationService {
+  rpc CheckCancellation(CheckCancellationRequest) returns (CheckCancellationResponse);
+}
+
+message CheckCancellationRequest {
+  // The request header
+  cmp.types.v1.RequestHeader header = 1;
+
+  // The token id of the booking to be cancelled
+  uint64 token_id = 2;
+
+  // The amount to be refunded
+  cmp.types.v2.Price refund_amount = 3;
+}
+
+message CheckCancellationResponse {
+  // The response header
+  cmp.types.v1.ResponseHeader header = 1;
+
+  // The token id of the booking to be cancelled
+  uint64 token_id = 2;
+
+  // The amount to be refunded
+  cmp.types.v2.Price refund_amount = 3;
+
+  // The policy id applied
+  string policy_id_applied = 4;
+
+  // Status of the cancellation check
+  cmp.services.cancellation.v1.CancellationCheckStatus status = 5;
+
+  // Rejection reason
+  cmp.services.cancellation.v1.CancellationRejectionReason rejection_reason = 6;
+
+  // Cancellation check timestamp
+  google.protobuf.Timestamp timestamp = 7;
+}
+
+enum CancellationCheckStatus {
+  CANCELLATION_CHECK_STATUS_UNSPECIFIED = 0;
+  CANCELLATION_CHECK_STATUS_ALREADY_CANCELLED = 1;
+  CANCELLATION_CHECK_STATUS_CONFIRM = 2;
+  CANCELLATION_CHECK_STATUS_REJECT = 3;
+}
diff --git a/proto/cmp/services/cancellation/v1/counter.proto b/proto/cmp/services/cancellation/v1/counter.proto
index 80bf030..01af2be 100644
--- a/proto/cmp/services/cancellation/v1/counter.proto
+++ b/proto/cmp/services/cancellation/v1/counter.proto
@@ -8,20 +8,20 @@ import "cmp/types/v2/price.proto";
 // Request for countering a cancellation
 message CounterCancellationRequest {
   // Request header
-  optional cmp.types.v1.RequestHeader header = 1;
+  cmp.types.v1.RequestHeader header = 1;
 
   // Cancellation token ID
-  optional uint64 token_id = 2;
+  uint64 token_id = 2;
 
   // Refund amount to counter the cancellation proposal with
-  optional cmp.types.v2.Price refund_amount = 3;
+  cmp.types.v2.Price refund_amount = 3;
 }
 
 // Response for countering a cancellation
 message CounterCancellationResponse {
   // Response header
-  optional cmp.types.v1.ResponseHeader header = 1;
+  cmp.types.v1.ResponseHeader header = 1;
 
   // Counter cancellation transaction ID
-  optional string transaction_id = 2;
+  string transaction_id = 2;
 }

From 8a8fd3fefad9a2ca5fc2aa611390891fd8041e45 Mon Sep 17 00:00:00 2001
From: Ekrem Seren <ekrem.seren@gmail.com>
Date: Thu, 31 Oct 2024 02:39:47 +0300
Subject: [PATCH 6/7] fix diagram url

---
 proto/cmp/services/cancellation/v1/check.proto | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/proto/cmp/services/cancellation/v1/check.proto b/proto/cmp/services/cancellation/v1/check.proto
index ca86f9e..9f8c084 100644
--- a/proto/cmp/services/cancellation/v1/check.proto
+++ b/proto/cmp/services/cancellation/v1/check.proto
@@ -9,9 +9,9 @@ import "google/protobuf/timestamp.proto";
 
 // Service for checking cancellation
 //
-// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.dot.xs.svg)
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.proto.dot.xs.svg)
 //
-// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.dot.svg)
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/cancellation/v1/check.proto.dot.svg)
 service CheckCancellationService {
   rpc CheckCancellation(CheckCancellationRequest) returns (CheckCancellationResponse);
 }

From 748a7ad7be34a6b9c1f5a9eaa9a4cd698f5ecfb8 Mon Sep 17 00:00:00 2001
From: Sam Jaarsma C4T <sam.jaarsma@chain4travel.com>
Date: Mon, 4 Nov 2024 10:39:20 +0100
Subject: [PATCH 7/7] adding a basic introduction and link to docs

---
 proto/cmp/services/cancellation/v1/services.proto | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/proto/cmp/services/cancellation/v1/services.proto b/proto/cmp/services/cancellation/v1/services.proto
index ed13c86..a5f1325 100644
--- a/proto/cmp/services/cancellation/v1/services.proto
+++ b/proto/cmp/services/cancellation/v1/services.proto
@@ -1,5 +1,15 @@
 syntax = "proto3";
 
+// ## Cancellation Services
+//
+// The Cancellation services are used for any message type or vertical.
+// There is an imperative workflow, which has the purpose to register the
+// cancellation request moment, followed by both parties agreeing the cancellation
+// is possible and the refund amount on the blockchain, so that there will be no
+// disputes after a cancellation is executed.
+//
+// There is a detailed explanation on [Camino Docs](https://docs.camino.network/camino-messenger/cancellation)
+
 package cmp.services.cancellation.v1;
 
 import "cmp/services/cancellation/v1/accept.proto";