feat(custom-gate): implement custom chat gateway management API

im/api/gateway/v1/message.proto

@@ -277,6 +277,8 @@ message SendTextRequest {
 
   // Set by providers when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 23;
+
+  map<string, string> variables = 24;
 }
 
 // Represents a response to send a text message.
@@ -312,6 +314,11 @@ message SendDocumentRequest {
 
   // Set by providers when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 23;
+
+  // Variables seeded onto the thread when this message is the one that creates
+  // it; ignored on every later message. Providers fill it from the channel's
+  // first-message payload so a flow schema can route on the caller's own data.
+  map<string, string> variables = 24;
 }
 
 // Represents a response to send message with document.
@@ -374,6 +381,12 @@ message SendLocationRequest {
 
   // Set by providers when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 10;
+
+  // Platform message id, when the channel reports one.
+  string external_id = 11;
+
+  // ID of the message this is a reply to, as reported by the external channel.
+  string reply_to_external_id = 12;
 }
 
 // SendContactRequest sends contact information.
@@ -405,6 +418,12 @@ message SendContactRequest {
 
   // Set by providers when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 9;
+
+  // Platform message id, when the channel reports one.
+  string external_id = 10;
+
+  // ID of the message this is a reply to, as reported by the external channel.
+  string reply_to_external_id = 11;
 }
 
 // SendInteractiveMessageRequest sends a structured interactive message.

im/api/gateway/v1/message_history.proto

@@ -234,7 +234,7 @@ message Image {
 }
 
 message ReplyToMessage {
-  string id = 1;
+  string message_id = 1;
   ThreadMember sender = 2;
   string sender_id = 3;
 
@@ -249,6 +249,7 @@ message ReplyToMessage {
   optional string attachment_name = 8;
   optional string attachment_mime = 9;
   optional string attachment_address = 11;
+
   bool is_deleted = 10;
 }
 

im/service/provider/v1/custom_service.proto

@@ -0,0 +1,33 @@
+syntax = "proto3";
+
+package webitel.im.provider.v1;
+
+import "google/api/annotations.proto";
+import "service/provider/v1/entities.proto";
+import "service/provider/v1/messages.proto";
+
+option go_package = "github.com/webitel/im-provider-service/gen/go/api/v1;impb";
+
+/// CustomService defines the RPC methods for managing custom chat gateways —
+/// arbitrary external communication systems connected as a chat channel.
+service CustomService {
+  /// CreateCustomGate registers an external system as a messaging gateway.
+  rpc CreateCustomGate (webitel.im.provider.v1.ProviderCreateCustomGateRequest) returns (webitel.im.provider.v1.ProviderCreateCustomGateResponse) {
+    option (google.api.http) = { post: "/im/gates/custom", body: "*" };
+  }
+
+  /// GetCustomGate retrieves configuration and status for a custom gateway.
+  rpc GetCustomGate (webitel.im.provider.v1.ProviderGetCustomGateRequest) returns (webitel.im.provider.v1.ProviderGetCustomGateResponse) {
+    option (google.api.http) = { get: "/im/gates/custom/{id}" };
+  }
+
+  /// UpdateCustomGate updates custom gateway settings.
+  rpc UpdateCustomGate (webitel.im.provider.v1.ProviderUpdateCustomGateRequest) returns (webitel.im.provider.v1.ProviderUpdateCustomGateResponse) {
+    option (google.api.http) = { patch: "/im/gates/custom/{id}", body: "*" };
+  }
+
+  /// DeleteCustomGate removes the custom gateway integration.
+  rpc DeleteCustomGate (webitel.im.provider.v1.ProviderDeleteCustomGateRequest) returns (webitel.im.provider.v1.ProviderDeleteCustomGateResponse) {
+    option (google.api.http) = { delete: "/im/gates/custom/{id}" };
+  }
+}

im/service/provider/v1/entities.proto

@@ -106,3 +106,21 @@ message ProviderTelegramBotGate {
   int64 created_at = 7;
   int64 updated_at = 8;
 }
+
+message ProviderCustomGate {
+  string id = 1;
+  string name = 2;
+  string webhook_url = 3;
+  // Customer-side webhook Webitel posts operator replies and events to.
+  string callback_url = 4;
+  // Shared secret used to sign and verify X-Webitel-Sign in both directions; handled as sensitive.
+  string app_secret = 5;
+  // Optional CIDR allowlist; an empty list accepts any source address.
+  repeated string allowed_ips = 6;
+  int32 request_timeout_ms = 7;
+  int32 retry_attempts = 8;
+  webitel.im.provider.v1.ProviderStatus status = 9;
+  int64 created_at = 10; // Unix timestamp in milliseconds
+  int64 updated_at = 11; // Unix timestamp in milliseconds
+  bool enabled = 12;
+}

im/service/provider/v1/enums.proto

@@ -14,6 +14,7 @@ enum ProviderType {
   PROVIDER_TYPE_FACEBOOK     = 5;
   PROVIDER_TYPE_INSTAGRAM    = 6;
   PROVIDER_TYPE_WHATSAPP     = 7;
+  PROVIDER_TYPE_CUSTOM       = 8;
 }
 
 /// ProviderStatus represents the operational state of a provider gateway.

im/service/provider/v1/messages.proto

@@ -297,6 +297,48 @@ message ProviderUpdateViberGateResponse {
 message ProviderDeleteViberGateRequest { string id = 1; }
 message ProviderDeleteViberGateResponse { webitel.im.provider.v1.ProviderViberGate item = 1; }
 
+message ProviderCreateCustomGateRequest {
+  string name = 1; // Name of the gateway in Webitel
+  Peer peer = 2; // Webitel bot identity (sub and iss) the channel routes inbound messages to
+  string callback_url = 3; // Customer-side webhook; must be an absolute https URL
+  string app_secret = 4; // Shared signing secret; generated when empty
+  repeated string allowed_ips = 5; // Optional CIDR allowlist
+  int32 request_timeout_ms = 6; // Timeout of a single callback attempt; defaults when zero
+  int32 retry_attempts = 7; // Retries before a message is marked failed; defaults when zero
+  bool enabled = 8;
+}
+
+/// ProviderCreateCustomGateResponse returns the newly activated custom provider.
+message ProviderCreateCustomGateResponse {
+  webitel.im.provider.v1.ProviderCustomGate item = 1;
+}
+
+/// ProviderGetCustomGateRequest fetches a custom provider configuration.
+message ProviderGetCustomGateRequest { string id = 1; }
+message ProviderGetCustomGateResponse { webitel.im.provider.v1.ProviderCustomGate item = 1; }
+
+/// ProviderUpdateCustomGateRequest updates custom gateway settings.
+message ProviderUpdateCustomGateRequest {
+  string id = 1;
+  string name = 2;
+  Peer peer = 3; // Webitel bot identity (sub and iss)
+  string callback_url = 4;
+  string app_secret = 5; // New signing secret, if rotated
+  repeated string allowed_ips = 6;
+  int32 request_timeout_ms = 7;
+  int32 retry_attempts = 8;
+  bool enabled = 9;
+}
+
+/// ProviderUpdateCustomGateResponse returns the updated custom provider.
+message ProviderUpdateCustomGateResponse {
+  webitel.im.provider.v1.ProviderCustomGate item = 1;
+}
+
+/// ProviderDeleteCustomGateRequest removes the custom integration.
+message ProviderDeleteCustomGateRequest { string id = 1; }
+message ProviderDeleteCustomGateResponse { webitel.im.provider.v1.ProviderCustomGate item = 1; }
+
 // --- Generic Discovery & Resource Management ---
 
 /// ProviderListGatesRequest contains pagination and filtering logic for discovering providers.

im/service/thread/v1/message_history_service.proto

@@ -179,7 +179,7 @@ message System {
 }
 
 message ReplyToMessage {
-  string id = 1;
+  string message_id = 1;
   string sender_id = 2;
 
   reserved 3;
@@ -191,6 +191,7 @@ message ReplyToMessage {
   optional string attachment_name = 7;
   optional string attachment_mime = 8;
   optional string attachment_address = 10;
+
   bool is_deleted = 9;
 }
 

im/service/thread/v1/message_service.proto

@@ -254,6 +254,10 @@ message SendTextRequest {
 
   // Set when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 23;
+
+  // Variables seeded onto the thread when this message is the one that creates
+  // it; ignored on every later message.
+  map<string, string> variables = 24;
 }
 
 // Represents a response to send a text message.
@@ -292,6 +296,10 @@ message SendDocumentRequest {
 
   // Set when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 23;
+
+  // Variables seeded onto the thread when this message is the one that creates
+  // it; ignored on every later message.
+  map<string, string> variables = 24;
 }
 
 // Represents a response to send message with document.
@@ -360,6 +368,12 @@ message SendLocationRequest {
 
   // Set when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 12;
+
+  // Platform message id, when the channel reports one.
+  string external_id = 13;
+
+  // ID of the message this is a reply to, as reported by the external channel.
+  string reply_to_external_id = 14;
 }
 
 // SendContactRequest sends contact information.
@@ -397,6 +411,12 @@ message SendContactRequest {
 
   // Set when the channel reports this message was forwarded to us.
   optional ForwardOriginInput forward_origin = 12;
+
+  // Platform message id, when the channel reports one.
+  string external_id = 13;
+
+  // ID of the message this is a reply to, as reported by the external channel.
+  string reply_to_external_id = 14;
 }
 
 message SendSystemMessageRequest {

swagger/api.json

@@ -71253,7 +71253,7 @@
           "type": "string",
           "format": "int64"
         },
-        "id": {
+        "message_id": {
           "type": "string"
         },
         "is_deleted": {