diff --git a/proto/cmp/services/book/v1alpha/mint.proto b/proto/cmp/services/book/v1alpha/mint.proto
new file mode 100644
index 0000000..3a9fae6
--- /dev/null
+++ b/proto/cmp/services/book/v1alpha/mint.proto
@@ -0,0 +1,70 @@
+syntax = "proto3";
+
+package cmp.services.book.v1alpha;
+
+import "cmp/types/v1alpha/common.proto";
+import "cmp/types/v1alpha/language.proto";
+import "cmp/types/v1alpha/payment.proto";
+import "cmp/types/v1alpha/pubkey.proto";
+import "cmp/types/v1alpha/token.proto";
+import "cmp/types/v1alpha/traveller.proto";
+import "google/protobuf/timestamp.proto";
+
+message MintRequest {
+  // Message header
+  cmp.types.v1alpha.Header header = 1;
+
+  string validation_id = 2;
+
+  string external_session_id = 3;
+
+  cmp.types.v1alpha.Language language = 4;
+
+  string market = 5;
+
+  string booking_reference = 6;
+
+  repeated cmp.types.v1alpha.ExtensiveTraveller travellers = 7;
+
+  // The comments field is meant to pass noncommittal remarks entered by the
+  // end-consumer about the service reservation,  like "non-smoking room please",
+  // "top floor room please".
+  string comment = 8;
+
+  // Public keys that will be used to encrypt the private booking data
+  repeated cmp.types.v1alpha.PublicKey public_keys = 9;
+
+  // This field is only relevant for off chain virtual credit card payments.
+  cmp.types.v1alpha.AdditionalPaymentInfo additional_payment_info = 10;
+}
+
+message MintResponse {
+  // Message header
+  cmp.types.v1alpha.Header header = 1;
+
+  // This must be a UUID according to RFC 4122
+  string mint_id = 2;
+
+  // This must be a UUID according to RFC 4122
+  string validation_id = 3;
+
+  string provider_booking_reference = 4;
+
+  // The token that represents the booking of the service
+  cmp.types.v1alpha.BookingToken booking_token = 5;
+
+  string mint_transaction_id = 6;
+
+  google.protobuf.Timestamp booking_timestamp = 7;
+
+  // Transaction ID of the buy operation. This field is populated by the distributor
+  // (buyer) bot after the buy operation and passed to the distributor middleware
+  // (partner plugin) in the mint response.
+  string buy_transaction_id = 8;
+}
+
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/book/v1alpha/mint.proto.dot.xs.svg)
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/book/v1alpha/mint.proto.dot.svg)
+service MintService {
+  rpc Mint(MintRequest) returns (MintResponse);
+}
diff --git a/proto/cmp/services/book/v1alpha/validate.proto b/proto/cmp/services/book/v1alpha/validate.proto
new file mode 100644
index 0000000..5dfc573
--- /dev/null
+++ b/proto/cmp/services/book/v1alpha/validate.proto
@@ -0,0 +1,45 @@
+syntax = "proto3";
+
+package cmp.services.book.v1alpha;
+
+import "cmp/types/v1alpha/common.proto";
+import "cmp/types/v1alpha/price.proto";
+
+message ValidationRequest {
+  // Message header
+  cmp.types.v1alpha.Header header = 1;
+
+  // Search ID that is returned in the search response message in the `metadata``
+  // (`SearchResponseMetadata`) field.
+  string search_id = 2;
+
+  // Result ID that is that is returned by `result_id` field of the search result
+  // messages, for example: `AccommodationSearchResult`.
+  int32 result_id = 3;
+}
+
+message ValidationResponse {
+  // Message header
+  cmp.types.v1alpha.Header header = 1;
+
+  // Unique validation ID. This must be a UUID according to RFC 4122
+  string validation_id = 2;
+
+  // Validation object
+  ValidationObject validation_object = 3;
+}
+
+// Validation message that represents a single `result_id` from the search results
+// message.
+//
+// TODO: Better name?
+message ValidationObject {
+  int32 result_id = 1;
+  cmp.types.v1alpha.PriceDetail price_detail = 2;
+}
+
+// ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/book/v1alpha/validate.proto.dot.xs.svg)
+// [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/services/book/v1alpha/validate.proto.dot.svg)
+service ValidationService {
+  rpc Validation(ValidationRequest) returns (ValidationResponse);
+}
diff --git a/proto/cmp/types/v1alpha/credit_card.proto b/proto/cmp/types/v1alpha/credit_card.proto
new file mode 100644
index 0000000..afed2ce
--- /dev/null
+++ b/proto/cmp/types/v1alpha/credit_card.proto
@@ -0,0 +1,12 @@
+syntax = "proto3";
+
+package cmp.types.v1alpha;
+
+import "cmp/types/v1alpha/date.proto";
+
+message CreditCard {
+  // FIXME: Can we use an int64 to represent a credit card number?
+  string number = 1;
+  Date expiration_date = 2;
+  int32 cvc = 3;
+}
diff --git a/proto/cmp/types/v1alpha/payment.proto b/proto/cmp/types/v1alpha/payment.proto
new file mode 100644
index 0000000..0bc410c
--- /dev/null
+++ b/proto/cmp/types/v1alpha/payment.proto
@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package cmp.types.v1alpha;
+
+import "cmp/types/v1alpha/credit_card.proto";
+
+// Additional payment info message with currently only a single field of
+// `CreditCard` message type.
+message AdditionalPaymentInfo {
+  CreditCard credit_card = 1;
+}
diff --git a/proto/cmp/types/v1alpha/pubkey.proto b/proto/cmp/types/v1alpha/pubkey.proto
new file mode 100644
index 0000000..33a9fbc
--- /dev/null
+++ b/proto/cmp/types/v1alpha/pubkey.proto
@@ -0,0 +1,7 @@
+syntax = "proto3";
+
+package cmp.types.v1alpha;
+
+message PublicKey {
+  string key = 1;
+}
diff --git a/proto/cmp/types/v1alpha/token.proto b/proto/cmp/types/v1alpha/token.proto
index d617712..d42aaf3 100644
--- a/proto/cmp/types/v1alpha/token.proto
+++ b/proto/cmp/types/v1alpha/token.proto
@@ -9,3 +9,13 @@ package cmp.types.v1alpha;
 message TokenCurrency {
   string contract_address = 1;
 }
+
+// Booking token that represents to access to the service
+message BookingToken {
+  // Contract address of the smart contract or the address of natively implemented
+  // asset on-chain.
+  string contract = 1;
+
+  // Token ID
+  int32 token_id = 2;
+}
diff --git a/proto/cmp/types/v1alpha/traveller.proto b/proto/cmp/types/v1alpha/traveller.proto
index 38b5420..c765493 100644
--- a/proto/cmp/types/v1alpha/traveller.proto
+++ b/proto/cmp/types/v1alpha/traveller.proto
@@ -10,7 +10,6 @@ import "cmp/types/v1alpha/document.proto";
 //
 // ![Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/types/v1alpha/traveller.proto.dot.xs.svg)
 // [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/types/v1alpha/traveller.proto.dot.svg)
-
 message BasicTraveller {
   // Guest number, the lowest number is the lead-pax. This ID is also used for
   // referencing services linked to specific participants, like baggage.
@@ -64,9 +63,9 @@ message ExtensiveTraveller {
   // into first_name: John, first_name: Roger, surname: Stephens, surname: Legend.
   repeated string first_names = 3;
   repeated string surnames = 4;
-  string phone_number = 6;
-  string email = 7;
-  repeated cmp.types.v1alpha.Document documents = 8;
+  string phone_number = 5;
+  string email = 6;
+  repeated cmp.types.v1alpha.Document documents = 7;
 }
 
 // Gender Type