Add EphemeralChatId and identifier-sourced ephemeral defaults

New EphemeralChatId inheritor of IdChatIdentifier carrying receiverUser and
ephemeralMessageId (mirroring ChatIdWithThreadId), with ChatIdentifier.receiverUser/
ephemeralMessageId extensions like ChatIdentifier.threadId. Every send/reply/edit/
delete method that takes receiverUserId/ephemeralMessageId now defaults them from
the chat identifier, so passing an EphemeralChatId auto-fills them the same way a
ChatIdWithThreadId fills threadId.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tgbotapi.core/api/tgbotapi.core.api

@@ -747,6 +747,7 @@ public final class dev/inmo/tgbotapi/bot/settings/limiters/RequestLimiter$Defaul
 
 public final class dev/inmo/tgbotapi/requests/DeleteEphemeralMessage : dev/inmo/tgbotapi/abstracts/types/EphemeralMessageAction, dev/inmo/tgbotapi/requests/abstracts/SimpleRequest {
 	public static final field Companion Ldev/inmo/tgbotapi/requests/DeleteEphemeralMessage$Companion;
+	public synthetic fun <init> (Ldev/inmo/tgbotapi/types/ChatIdentifier;Ldev/inmo/tgbotapi/types/IdChatIdentifier;JILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public synthetic fun <init> (Ldev/inmo/tgbotapi/types/ChatIdentifier;Ldev/inmo/tgbotapi/types/IdChatIdentifier;JLkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ldev/inmo/tgbotapi/types/ChatIdentifier;
 	public final fun component2 ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
@@ -11004,6 +11005,10 @@ public final class dev/inmo/tgbotapi/types/BusinessChatId : dev/inmo/tgbotapi/ty
 	public final fun getChatIdWithBusinessConnectionId ()Lkotlin/Pair;
 	public fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
 	public static fun getDirectMessageThreadId-1osv_qQ (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getEphemeralMessageId-lUwSvXo (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public static fun getReceiverUser-impl (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public static fun getThreadId-S3HF-10 (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public fun hashCode ()I
@@ -11059,6 +11064,10 @@ public final class dev/inmo/tgbotapi/types/ChatId : dev/inmo/tgbotapi/types/IdCh
 	public fun getChatId-iyD94Bc ()J
 	public fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
 	public static fun getDirectMessageThreadId-1osv_qQ (J)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getEphemeralMessageId-lUwSvXo (J)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public static fun getReceiverUser-impl (J)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public static fun getThreadId-S3HF-10 (J)Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public fun hashCode ()I
@@ -11088,6 +11097,10 @@ public final class dev/inmo/tgbotapi/types/ChatIdWithChannelDirectMessageThreadI
 	public synthetic fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
 	public fun getDirectMessageThreadId-_JBF_Q4 ()J
 	public static fun getDirectMessageThreadId-_JBF_Q4 (Lkotlin/Pair;)J
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getEphemeralMessageId-lUwSvXo (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public static fun getReceiverUser-impl (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public static fun getThreadId-S3HF-10 (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public fun hashCode ()I
@@ -11116,6 +11129,10 @@ public final class dev/inmo/tgbotapi/types/ChatIdWithThreadId : dev/inmo/tgbotap
 	public final fun getChatIdWithThreadId ()Lkotlin/Pair;
 	public fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
 	public static fun getDirectMessageThreadId-1osv_qQ (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getEphemeralMessageId-lUwSvXo (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public static fun getReceiverUser-impl (Lkotlin/Pair;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public synthetic fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public fun getThreadId-hDmiKeI ()J
 	public static fun getThreadId-hDmiKeI (Lkotlin/Pair;)J
@@ -11145,6 +11162,8 @@ public final class dev/inmo/tgbotapi/types/ChatIdentifierKt {
 	public static final field managedBotNewBotUsername Ljava/lang/String;
 	public static final fun getBusinessConnectionId (Ldev/inmo/tgbotapi/types/ChatIdentifier;)Ljava/lang/String;
 	public static final fun getDirectMessageThreadId (Ldev/inmo/tgbotapi/types/ChatIdentifier;)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public static final fun getEphemeralMessageId (Ldev/inmo/tgbotapi/types/ChatIdentifier;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static final fun getReceiverUser (Ldev/inmo/tgbotapi/types/ChatIdentifier;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public static final fun getThreadId (Ldev/inmo/tgbotapi/types/ChatIdentifier;)Ldev/inmo/tgbotapi/types/MessageThreadId;
 	public static final fun getUserLink (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ljava/lang/String;
 	public static final fun getUserLink (Ldev/inmo/tgbotapi/types/chat/User;)Ljava/lang/String;
@@ -11157,6 +11176,8 @@ public final class dev/inmo/tgbotapi/types/ChatIdentifierKt {
 	public static final fun toChatId-0218hRU (J)J
 	public static final fun toChatIdWithChannelDirectMessageThreadId-KSqvWnI (Ldev/inmo/tgbotapi/types/IdChatIdentifier;J)Lkotlin/Pair;
 	public static final fun toChatWithThreadId-krPZAoY (Ldev/inmo/tgbotapi/types/IdChatIdentifier;J)Lkotlin/Pair;
+	public static final fun toEphemeralChatId-oQsLJhk (Ldev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;)Lkotlin/Triple;
+	public static synthetic fun toEphemeralChatId-oQsLJhk$default (Ldev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;ILjava/lang/Object;)Lkotlin/Triple;
 	public static final fun toUsername (Ljava/lang/String;)Ljava/lang/String;
 }
 
@@ -12506,6 +12527,39 @@ public final class dev/inmo/tgbotapi/types/EffectId$Companion {
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
+public final class dev/inmo/tgbotapi/types/EphemeralChatId : dev/inmo/tgbotapi/types/IdChatIdentifier {
+	public static final field Companion Ldev/inmo/tgbotapi/types/EphemeralChatId$Companion;
+	public static final synthetic fun box-impl (Lkotlin/Triple;)Ldev/inmo/tgbotapi/types/EphemeralChatId;
+	public static fun constructor-impl (JLdev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;)Lkotlin/Triple;
+	public static fun constructor-impl (Lkotlin/Triple;)Lkotlin/Triple;
+	public static synthetic fun constructor-impl$default (JLdev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;ILkotlin/jvm/internal/DefaultConstructorMarker;)Lkotlin/Triple;
+	public fun equals (Ljava/lang/Object;)Z
+	public static fun equals-impl (Lkotlin/Triple;Ljava/lang/Object;)Z
+	public static final fun equals-impl0 (Lkotlin/Triple;Lkotlin/Triple;)Z
+	public fun getBusinessConnectionId-nXr5wdE ()Ljava/lang/String;
+	public static fun getBusinessConnectionId-nXr5wdE (Lkotlin/Triple;)Ljava/lang/String;
+	public fun getChatId-iyD94Bc ()J
+	public static fun getChatId-iyD94Bc (Lkotlin/Triple;)J
+	public final fun getChatIdWithReceiverUserAndEphemeralMessageId ()Lkotlin/Triple;
+	public fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public static fun getDirectMessageThreadId-1osv_qQ (Lkotlin/Triple;)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getEphemeralMessageId-lUwSvXo (Lkotlin/Triple;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public static fun getReceiverUser-impl (Lkotlin/Triple;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
+	public fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
+	public static fun getThreadId-S3HF-10 (Lkotlin/Triple;)Ldev/inmo/tgbotapi/types/MessageThreadId;
+	public fun hashCode ()I
+	public static fun hashCode-impl (Lkotlin/Triple;)I
+	public fun toString ()Ljava/lang/String;
+	public static fun toString-impl (Lkotlin/Triple;)Ljava/lang/String;
+	public final synthetic fun unbox-impl ()Lkotlin/Triple;
+}
+
+public final class dev/inmo/tgbotapi/types/EphemeralChatId$Companion {
+	public final fun serializer ()Lkotlinx/serialization/KSerializer;
+}
+
 public final class dev/inmo/tgbotapi/types/EphemeralMessageId {
 	public static final field Companion Ldev/inmo/tgbotapi/types/EphemeralMessageId$Companion;
 	public static final synthetic fun box-impl (J)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
@@ -12656,6 +12710,8 @@ public abstract interface class dev/inmo/tgbotapi/types/IdChatIdentifier : dev/i
 	public fun getBusinessConnectionId-nXr5wdE ()Ljava/lang/String;
 	public abstract fun getChatId-iyD94Bc ()J
 	public fun getDirectMessageThreadId-1osv_qQ ()Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public fun getEphemeralMessageId-lUwSvXo ()Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public fun getReceiverUser ()Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public fun getThreadId-S3HF-10 ()Ldev/inmo/tgbotapi/types/MessageThreadId;
 }
 
@@ -12664,12 +12720,16 @@ public final class dev/inmo/tgbotapi/types/IdChatIdentifier$Companion {
 	public static synthetic fun invoke-2eCI0EE$default (Ldev/inmo/tgbotapi/types/IdChatIdentifier$Companion;JLdev/inmo/tgbotapi/types/MessageThreadId;Ljava/lang/String;ILjava/lang/Object;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public final fun invoke-8eqqXtU (JJ)Lkotlin/Pair;
 	public final fun invoke-bxO6wVA (JLjava/lang/String;)Lkotlin/Pair;
+	public final fun invoke-qw8KcVY (JLdev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;)Lkotlin/Triple;
+	public static synthetic fun invoke-qw8KcVY$default (Ldev/inmo/tgbotapi/types/IdChatIdentifier$Companion;JLdev/inmo/tgbotapi/types/IdChatIdentifier;Ldev/inmo/tgbotapi/types/EphemeralMessageId;ILjava/lang/Object;)Lkotlin/Triple;
 	public final fun serializer ()Lkotlinx/serialization/KSerializer;
 }
 
 public final class dev/inmo/tgbotapi/types/IdChatIdentifier$DefaultImpls {
 	public static fun getBusinessConnectionId-nXr5wdE (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ljava/lang/String;
 	public static fun getDirectMessageThreadId-1osv_qQ (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ldev/inmo/tgbotapi/types/DirectMessageThreadId;
+	public static fun getEphemeralMessageId-lUwSvXo (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ldev/inmo/tgbotapi/types/EphemeralMessageId;
+	public static fun getReceiverUser (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ldev/inmo/tgbotapi/types/IdChatIdentifier;
 	public static fun getThreadId-S3HF-10 (Ldev/inmo/tgbotapi/types/IdChatIdentifier;)Ldev/inmo/tgbotapi/types/MessageThreadId;
 }
 

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/DeleteEphemeralMessage.kt

@@ -11,10 +11,14 @@ import kotlinx.serialization.builtins.serializer
 data class DeleteEphemeralMessage(
     @SerialName(chatIdField)
     override val chatId: ChatIdentifier,
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId,
+    @EncodeDefault
+    override val receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(ephemeralMessageIdField)
-    override val ephemeralMessageId: EphemeralMessageId
+    @EncodeDefault
+    override val ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" }
 ) : SimpleRequest<Unit>, EphemeralMessageAction {
     override fun method(): String = "deleteEphemeralMessage"
 

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/edit/caption/EditEphemeralMessageCaption.kt

@@ -16,8 +16,8 @@ const val editEphemeralMessageCaptionMethod = "editEphemeralMessageCaption"
 
 fun EditEphemeralMessageCaption(
     chatId: ChatIdentifier,
-    receiverUserId: UserId,
-    ephemeralMessageId: EphemeralMessageId,
+    receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     caption: String? = null,
     parseMode: ParseMode? = null,
     replyMarkup: InlineKeyboardMarkup? = null
@@ -33,8 +33,8 @@ fun EditEphemeralMessageCaption(
 
 fun EditEphemeralMessageCaption(
     chatId: ChatIdentifier,
-    receiverUserId: UserId,
-    ephemeralMessageId: EphemeralMessageId,
+    receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     entities: TextSourcesList,
     replyMarkup: InlineKeyboardMarkup? = null
 ) = EditEphemeralMessageCaption(
@@ -52,10 +52,14 @@ fun EditEphemeralMessageCaption(
 data class EditEphemeralMessageCaption internal constructor(
     @SerialName(chatIdField)
     override val chatId: ChatIdentifier,
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId,
+    @EncodeDefault
+    override val receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(ephemeralMessageIdField)
-    override val ephemeralMessageId: EphemeralMessageId,
+    @EncodeDefault
+    override val ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     @SerialName(captionField)
     override val text: String? = null,
     @SerialName(parseModeField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/edit/media/EditEphemeralMessageMedia.kt

@@ -13,10 +13,14 @@ const val editEphemeralMessageMediaMethod = "editEphemeralMessageMedia"
 data class EditEphemeralMessageMedia(
     @SerialName(chatIdField)
     override val chatId: ChatIdentifier,
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId,
+    @EncodeDefault
+    override val receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(ephemeralMessageIdField)
-    override val ephemeralMessageId: EphemeralMessageId,
+    @EncodeDefault
+    override val ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     @Suppress("SERIALIZER_TYPE_INCOMPATIBLE")
     @SerialName(mediaField)
     override val media: TelegramFreeMedia,

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/edit/reply_markup/EditEphemeralMessageReplyMarkup.kt

@@ -12,10 +12,14 @@ const val editEphemeralMessageReplyMarkupMethod = "editEphemeralMessageReplyMark
 data class EditEphemeralMessageReplyMarkup(
     @SerialName(chatIdField)
     override val chatId: ChatIdentifier,
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId,
+    @EncodeDefault
+    override val receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(ephemeralMessageIdField)
-    override val ephemeralMessageId: EphemeralMessageId,
+    @EncodeDefault
+    override val ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     @SerialName(replyMarkupField)
     override val replyMarkup: InlineKeyboardMarkup? = null
 ) : EditEphemeralMessage, EditReplyMessage {

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/edit/text/EditEphemeralMessageText.kt

@@ -17,8 +17,8 @@ const val editEphemeralMessageTextMethod = "editEphemeralMessageText"
 
 fun EditEphemeralMessageText(
     chatId: ChatIdentifier,
-    receiverUserId: UserId,
-    ephemeralMessageId: EphemeralMessageId,
+    receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     text: String,
     parseMode: ParseMode? = null,
     linkPreviewOptions: LinkPreviewOptions? = null,
@@ -36,8 +36,8 @@ fun EditEphemeralMessageText(
 
 fun EditEphemeralMessageText(
     chatId: ChatIdentifier,
-    receiverUserId: UserId,
-    ephemeralMessageId: EphemeralMessageId,
+    receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     entities: TextSourcesList,
     linkPreviewOptions: LinkPreviewOptions? = null,
     replyMarkup: InlineKeyboardMarkup? = null
@@ -57,10 +57,14 @@ fun EditEphemeralMessageText(
 data class EditEphemeralMessageText internal constructor(
     @SerialName(chatIdField)
     override val chatId: ChatIdentifier,
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId,
+    @EncodeDefault
+    override val receiverUserId: UserId = requireNotNull(chatId.receiverUser) { "receiverUserId was not provided and chatId ($chatId) is not an EphemeralChatId" },
+    @OptIn(ExperimentalSerializationApi::class)
     @SerialName(ephemeralMessageIdField)
-    override val ephemeralMessageId: EphemeralMessageId,
+    @EncodeDefault
+    override val ephemeralMessageId: EphemeralMessageId = requireNotNull(chatId.ephemeralMessageId) { "ephemeralMessageId was not provided and chatId ($chatId) does not carry an ephemeralMessageId" },
     @SerialName(textField)
     override val text: String,
     @SerialName(parseModeField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/SendContact.kt

@@ -38,7 +38,7 @@ data class SendContact(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)
@@ -65,7 +65,7 @@ data class SendContact(
         threadId: MessageThreadId? = chatId.threadId,
         directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
         businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-        receiverUserId: UserId? = null,
+        receiverUserId: UserId? = chatId.receiverUser,
         callbackQueryId: CallbackQueryId? = null,
         disableNotification: Boolean = false,
         protectContent: Boolean = false,
@@ -105,7 +105,7 @@ fun Contact.toRequest(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/SendLocation.kt

@@ -34,7 +34,7 @@ fun SendLocation(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -68,7 +68,7 @@ fun SendStaticLocation(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -111,7 +111,7 @@ fun SendLiveLocation(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -189,7 +189,7 @@ sealed interface SendLocation<T : LocationContent> : SendContentMessageRequest<C
         @EncodeDefault
         override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
         @SerialName(receiverUserIdField)
-        override val receiverUserId: UserId? = null,
+        override val receiverUserId: UserId? = chatId.receiverUser,
         @SerialName(callbackQueryIdField)
         override val callbackQueryId: CallbackQueryId? = null,
         @SerialName(disableNotificationField)
@@ -243,7 +243,7 @@ sealed interface SendLocation<T : LocationContent> : SendContentMessageRequest<C
         @EncodeDefault
         override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
         @SerialName(receiverUserIdField)
-        override val receiverUserId: UserId? = null,
+        override val receiverUserId: UserId? = chatId.receiverUser,
         @SerialName(callbackQueryIdField)
         override val callbackQueryId: CallbackQueryId? = null,
         @SerialName(disableNotificationField)
@@ -299,7 +299,7 @@ sealed interface SendLocation<T : LocationContent> : SendContentMessageRequest<C
             @SerialName(businessConnectionIdField)
             val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
             @SerialName(receiverUserIdField)
-            val receiverUserId: UserId? = null,
+            val receiverUserId: UserId? = chatId.receiverUser,
             @SerialName(callbackQueryIdField)
             val callbackQueryId: CallbackQueryId? = null,
             @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/SendMessage.kt

@@ -30,7 +30,7 @@ fun SendTextMessage(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -66,7 +66,7 @@ fun SendTextMessage(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -117,7 +117,7 @@ data class SendTextMessage internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(linkPreviewOptionsField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/SendVenue.kt

@@ -46,7 +46,7 @@ data class SendVenue(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)
@@ -75,7 +75,7 @@ data class SendVenue(
         threadId: MessageThreadId? = chatId.threadId,
         directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
         businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-        receiverUserId: UserId? = null,
+        receiverUserId: UserId? = chatId.receiverUser,
         callbackQueryId: CallbackQueryId? = null,
         disableNotification: Boolean = false,
         protectContent: Boolean = false,
@@ -120,7 +120,7 @@ fun Venue.toRequest(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendAnimation.kt

@@ -38,7 +38,7 @@ fun SendAnimation(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -100,7 +100,7 @@ fun SendAnimation(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -188,7 +188,7 @@ data class SendAnimationData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendAudio.kt

@@ -37,7 +37,7 @@ fun SendAudio(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -95,7 +95,7 @@ fun SendAudio(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -177,7 +177,7 @@ data class SendAudioData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendDocument.kt

@@ -42,7 +42,7 @@ fun SendDocument(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -105,7 +105,7 @@ fun SendDocument(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -189,7 +189,7 @@ data class SendDocumentData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendLivePhoto.kt

@@ -35,7 +35,7 @@ fun SendLivePhoto(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -91,7 +91,7 @@ fun SendLivePhoto(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -170,7 +170,7 @@ data class SendLivePhotoData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendPhoto.kt

@@ -33,7 +33,7 @@ fun SendPhoto(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -83,7 +83,7 @@ fun SendPhoto(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -156,7 +156,7 @@ data class SendPhotoData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendSticker.kt

@@ -23,7 +23,7 @@ fun SendSticker(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     emoji: String? = null,
     disableNotification: Boolean = false,
@@ -80,7 +80,7 @@ data class SendStickerByFileId internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(emojiField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendVideo.kt

@@ -43,7 +43,7 @@ fun SendVideo(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -112,7 +112,7 @@ fun SendVideo(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -210,7 +210,7 @@ data class SendVideoData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendVideoNote.kt

@@ -25,7 +25,7 @@ fun SendVideoNote(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -95,7 +95,7 @@ data class SendVideoNoteData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/requests/send/media/SendVoice.kt

@@ -31,7 +31,7 @@ fun SendVoice(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     disableNotification: Boolean = false,
     protectContent: Boolean = false,
@@ -81,7 +81,7 @@ fun SendVoice(
     threadId: MessageThreadId? = chatId.threadId,
     directMessageThreadId: DirectMessageThreadId? = chatId.directMessageThreadId,
     businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
-    receiverUserId: UserId? = null,
+    receiverUserId: UserId? = chatId.receiverUser,
     callbackQueryId: CallbackQueryId? = null,
     duration: Long? = null,
     disableNotification: Boolean = false,
@@ -154,7 +154,7 @@ data class SendVoiceData internal constructor(
     @SerialName(businessConnectionIdField)
     override val businessConnectionId: BusinessConnectionId? = chatId.businessConnectionId,
     @SerialName(receiverUserIdField)
-    override val receiverUserId: UserId? = null,
+    override val receiverUserId: UserId? = chatId.receiverUser,
     @SerialName(callbackQueryIdField)
     override val callbackQueryId: CallbackQueryId? = null,
     @SerialName(disableNotificationField)

tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/ChatIdentifier.kt

@@ -39,6 +39,10 @@ sealed interface IdChatIdentifier : ChatIdentifier {
         get() = null
     val directMessageThreadId: DirectMessageThreadId?
         get() = null
+    val receiverUser: UserId?
+        get() = null
+    val ephemeralMessageId: EphemeralMessageId?
+        get() = null
 
     companion object {
         operator fun invoke(chatId: RawChatId, threadId: MessageThreadId? = null, businessConnectionId: BusinessConnectionId? = null) = threadId ?.let {
@@ -48,6 +52,7 @@ sealed interface IdChatIdentifier : ChatIdentifier {
         } ?: ChatId(chatId)
         operator fun invoke(chatId: RawChatId, threadId: MessageThreadId) = ChatIdWithThreadId(chatId, threadId)
         operator fun invoke(chatId: RawChatId, businessConnectionId: BusinessConnectionId) = BusinessChatId(chatId, businessConnectionId)
+        operator fun invoke(chatId: RawChatId, receiverUser: UserId, ephemeralMessageId: EphemeralMessageId? = null) = EphemeralChatId(chatId, receiverUser, ephemeralMessageId)
     }
 }
 
@@ -91,6 +96,26 @@ value class BusinessChatId(val chatIdWithBusinessConnectionId: Pair<RawChatId, B
     constructor(chatId: RawChatId, businessConnectionId: BusinessConnectionId): this(chatId to businessConnectionId)
 }
 
+/**
+ * Chat id of group/supergroup additionally carrying ephemeral [receiverUser] (and optional [ephemeralMessageId]);
+ * used to default `receiverUserId`/`ephemeralMessageId` params of ephemeral-related requests
+ */
+@Suppress("SERIALIZER_TYPE_INCOMPATIBLE")
+@Serializable(ChatIdentifierSerializer::class)
+@JvmInline
+value class EphemeralChatId(
+    val chatIdWithReceiverUserAndEphemeralMessageId: Triple<RawChatId, UserId, EphemeralMessageId?>
+) : IdChatIdentifier {
+    override val chatId: RawChatId
+        get() = chatIdWithReceiverUserAndEphemeralMessageId.first
+    override val receiverUser: UserId
+        get() = chatIdWithReceiverUserAndEphemeralMessageId.second
+    override val ephemeralMessageId: EphemeralMessageId?
+        get() = chatIdWithReceiverUserAndEphemeralMessageId.third
+
+    constructor(chatId: RawChatId, receiverUser: UserId, ephemeralMessageId: EphemeralMessageId? = null): this(Triple(chatId, receiverUser, ephemeralMessageId))
+}
+
 val ChatIdentifier.threadId: MessageThreadId?
     get() = (this as? IdChatIdentifier) ?.threadId
 
@@ -100,16 +125,24 @@ val ChatIdentifier.directMessageThreadId: DirectMessageThreadId?
 val ChatIdentifier.businessConnectionId: BusinessConnectionId?
     get() = (this as? IdChatIdentifier) ?.businessConnectionId
 
+val ChatIdentifier.receiverUser: UserId?
+    get() = (this as? IdChatIdentifier) ?.receiverUser
+
+val ChatIdentifier.ephemeralMessageId: EphemeralMessageId?
+    get() = (this as? IdChatIdentifier) ?.ephemeralMessageId
+
 fun IdChatIdentifier.toChatId() = when (this) {
     is ChatId -> this
     is ChatIdWithThreadId -> ChatId(chatId)
     is ChatIdWithChannelDirectMessageThreadId -> ChatId(chatId)
     is BusinessChatId -> ChatId(chatId)
+    is EphemeralChatId -> ChatId(chatId)
 }
 
 fun IdChatIdentifier.toChatWithThreadId(threadId: MessageThreadId) = IdChatIdentifier(chatId, threadId)
 fun IdChatIdentifier.toChatIdWithChannelDirectMessageThreadId(threadId: DirectMessageThreadId) = ChatIdWithChannelDirectMessageThreadId(chatId, threadId)
 fun IdChatIdentifier.toBusinessChatId(businessConnectionId: BusinessConnectionId) = IdChatIdentifier(chatId, businessConnectionId)
+fun IdChatIdentifier.toEphemeralChatId(receiverUser: UserId, ephemeralMessageId: EphemeralMessageId? = null) = IdChatIdentifier(chatId, receiverUser, ephemeralMessageId)
 
 /**
  * https://core.telegram.org/bots/api#formatting-options
@@ -256,6 +289,17 @@ object FullChatIdentifierSerializer : KSerializer<ChatIdentifier> {
                         )
                     }
                 }
+                4 -> {
+                    val (chatId, intermediateDelimiter, receiverUserChatId, ephemeralMessageId) = splitted
+                    when (intermediateDelimiter) {
+                        "eph" -> EphemeralChatId(
+                            chatId.toLongOrNull() ?.let(::RawChatId) ?: return@let null,
+                            receiverUserChatId.toLongOrNull() ?.let { ChatId(RawChatId(it)) } ?: return@let null,
+                            ephemeralMessageId.toLongOrNull() ?.let(::EphemeralMessageId)
+                        )
+                        else -> null
+                    }
+                }
                 else -> null
             }
         } ?: id.content.let {
@@ -269,6 +313,7 @@ object FullChatIdentifierSerializer : KSerializer<ChatIdentifier> {
             is ChatIdWithThreadId -> encoder.encodeString("${value.chatId}/${value.threadId}")
             is BusinessChatId -> encoder.encodeString("${value.chatId}//${value.businessConnectionId}")
             is ChatIdWithChannelDirectMessageThreadId -> encoder.encodeString("${value.chatId}/cdm/${value.directMessageThreadId}")
+            is EphemeralChatId -> encoder.encodeString("${value.chatId}/eph/${value.receiverUser.chatId}/${value.ephemeralMessageId?.long ?: ""}")
             is Username -> encoder.encodeString(value.full)
         }
     }

tgbotapi.core/src/commonTest/kotlin/dev/inmo/tgbotapi/types/ChatIdentifierTests.kt

@@ -69,4 +69,31 @@ class ChatIdentifierTests {
             assertEquals(withUsername, deserialized)
         }
     }
+
+    @Test
+    fun `EphemeralChatId_is_serialized_as_bare_long_by_ChatIdentifierSerializer`() {
+        val ephemeralChatId = EphemeralChatId(chatIdentifierChatId, ChatId(RawChatId(456L)))
+        val stringified = TestsJsonFormat.encodeToString(ChatIdentifierSerializer, ephemeralChatId as ChatIdentifier)
+        assertEquals("$chatIdentifierChatId", stringified)
+        val deserialized = TestsJsonFormat.decodeFromString(ChatIdentifierSerializer, stringified)
+        assertEquals(ChatId(chatIdentifierChatId), deserialized)
+    }
+
+    @Test
+    fun `EphemeralChatId_round_trips_through_FullChatIdentifierSerializer_with_ephemeralMessageId`() {
+        val ephemeralChatId = EphemeralChatId(chatIdentifierChatId, ChatId(RawChatId(456L)), EphemeralMessageId(789L))
+        val stringified = TestsJsonFormat.encodeToString(FullChatIdentifierSerializer, ephemeralChatId as ChatIdentifier)
+        assertEquals("\"$chatIdentifierChatId/eph/456/789\"", stringified)
+        val deserialized = TestsJsonFormat.decodeFromString(FullChatIdentifierSerializer, stringified)
+        assertEquals(ephemeralChatId, deserialized)
+    }
+
+    @Test
+    fun `EphemeralChatId_round_trips_through_FullChatIdentifierSerializer_without_ephemeralMessageId`() {
+        val ephemeralChatId = EphemeralChatId(chatIdentifierChatId, ChatId(RawChatId(456L)))
+        val stringified = TestsJsonFormat.encodeToString(FullChatIdentifierSerializer, ephemeralChatId as ChatIdentifier)
+        assertEquals("\"$chatIdentifierChatId/eph/456/\"", stringified)
+        val deserialized = TestsJsonFormat.decodeFromString(FullChatIdentifierSerializer, stringified)
+        assertEquals(ephemeralChatId, deserialized)
+    }
 }