MCP data structures

These are the application result models exposed by the 70 MCP tools. Names such as McpChatInfo are .NET model names; tables use their JSON field names (camelCase). Requests consist of the tool arguments listed in the tool reference, not separate request-object types. Message and notification payloads use the shared ExternalMessage shape.

Identifiers and primitive values

Value	Meaning
User ID	Opaque string identifying an account. Obtain it from get_me, list_members or list_peer_chats.
Chat ID	Opaque string identifying a group, direct or place chat. Obtain it from a chat-list result and reuse it unchanged.
Place ID	Opaque string identifying a place, obtained from list_places. It is not the ID of a chat inside the place.
Message ID / LID / entryId	64-bit integer local to one chat. The pair (chatId, id) identifies a message. IDs can have gaps.
Author ID	String identifying an author within a chat (or a place's root chat). It is not interchangeable with a user ID.
Avatar ID, Invite ID, Upload ID, Stream ID, Conversation ID	Opaque strings returned by the tool that creates or lists them.
Media ID	String identifying a media object, returned by uploads and attachments. Use returned URLs to retrieve content.
Version	64-bit message version token for identifying changes. It is not a product release version or message ID.
Timestamps	Milliseconds since the Unix epoch (UTC), as 64-bit integers.

Use a JSON implementation that preserves 64-bit integers when storing message IDs, versions and timestamps. Do not derive chronological ordering from opaque string IDs.

Account and avatars

McpAccount

Field	Type	Meaning
userId	string	Your user ID.
name	string	Display name (the default avatar's name).
avatarId	string	Default avatar ID.
avatarName	string	Default avatar name.
avatarUrl	string or null	Default avatar picture URL.

McpAvatar

Field	Type	Meaning
id	string	Avatar ID.
name	string	Avatar name.
bio	string	Short bio; may be empty.
pictureUrl	string or null	Picture URL.
isDefault	boolean	This avatar is the account's default.

Places and chats

McpListPlacesResult / McpPlaceInfo

McpListPlacesResult has places (McpPlaceInfo[]; may be empty).

McpPlaceInfo field	Type	Meaning
id	string	Place ID.
isPublic	boolean	Whether the place is public.
title	string	Place title.

McpListChatsResult / McpChatInfo

McpListChatsResult has chats (McpChatInfo[]; may be empty).

McpChatInfo field	Type	Meaning
id	string	Chat ID.
isPublic	boolean	Whether the chat is public.
title	string	Chat title; direct chats can use the other person's display name as a fallback.

Neither list wrapper includes a total count or a separate next-page token. Reuse the final item's id as the exclusive cursor, following the caveats in the tool reference.

McpChatDetails

Field	Type	Meaning
id	string	Chat ID.
kind	string	Chat kind name (for example group, peer or place).
title, description	string	Title and description.
isPublic	boolean	Whether anyone can join.
placeId	string or null	Place ID for a place chat; otherwise null.
pictureUrl	string or null	Picture URL.
memberCount	integer	Number of authors listed for the chat.
permissions	string[]	Names of the permission flags the caller has, such as Invite or EditMembers.

McpPlaceDetails

Field	Type	Meaning
id	string	Place ID.
title, description	string	Title and description.
isPublic	boolean	Whether the place is public.
pictureUrl, backgroundUrl	string or null	Picture and background URLs.
memberCount	integer	Number of authors listed for the place.
permissions	string[]	Permission flag names the caller has.

McpListMembersResult / McpMember

McpListMembersResult has members (McpMember[]).

McpMember field	Type	Meaning
authorId	string	Author ID; also the paging cursor.
userId	string or null	User ID; User ID.
name	string	Author's avatar name.
isOwner	boolean	The member is an owner.

McpInviteLink

Field	Type	Meaning
id	string	Invite ID; pass to revoke_invite_link.
url	string	Absolute invite URL. Treat as a secret.
remaining	integer	Remaining uses.
expiresOn	64-bit integer	Expiry, Unix milliseconds.

Messages

McpIdRange of long

Field	Type	Meaning
firstId	64-bit integer	Inclusive first local message ID.
lastId	64-bit integer	Inclusive last local message ID.

An empty range has lastId < firstId. The underlying .NET model is generic McpIdRange<T>; MCP tools use it only with long.

McpListMessagesResult

Field	Type	Meaning
range	McpIdRange<long>	Inclusive bounds of this returned page, or an empty range.
fullRange	McpIdRange<long>	Chat's full local-ID range at the time of reading.
messages	ExternalMessage[]	Returned messages in ascending local-ID order.

ExternalMessage

Field	Type	Meaning
id	64-bit integer	Message's local ID in its chat.
version	64-bit integer	Message version token.
createdAt	64-bit integer	Message beginning time, Unix milliseconds.
author	ExternalAuthor	Author of the message.
isSystem	boolean	This is a system entry.
isStreaming	boolean	Content is currently streaming.
isTranscribed	boolean	The entry has associated audio. This is derived from the audio flag, not a transcript-quality guarantee.
isRemoved	boolean	Removal flag. Normal list_messages results omit removed entries.
text	string or null	Stored message content; null while isStreaming is true. May contain Voxt text markup. In-progress transcription is never exposed.
textTruncated	boolean or null	Set only by producers that truncate text; MCP leaves it null.
attachments	ExternalAttachment[]	Attached media metadata; empty if there are none.
repliedToId	64-bit integer or null	Local ID of the message this one replies to.
mentions	string[]	Author IDs mentioned in the text.
url	string	Absolute link to the message.
origin	ExternalOrigin	How the message was produced.

The model does not contain a reaction list, a thread model or an audio stream; use list_reactions for reactions.

ExternalAuthor

Field	Type	Meaning
id	string	Chat-specific author ID.
name	string	Author avatar name; empty if unavailable.
avatarUrl	string or null	Avatar picture URL.

ExternalOrigin

Field	Type	Meaning
kind	string	user, api (posted through an API key or MCP), webhook (posted through an incoming webhook) or bot.

ExternalAttachment

Field	Type	Meaning
mediaId	string	Backing media ID.
kind	string	image, video, audio or file, classified from content type.
fileName	string	Stored filename.
contentType	string	MIME content type.
length	64-bit integer	Media size in bytes.
width, height	integer	Stored pixel size where applicable.
url	string	Content URL.
previewUrl	string or null	Image preview URL when the image proxy is available; otherwise null.
thumbnailUrl	string or null	Thumbnail content URL when a thumbnail exists; otherwise null.

Do not require dimensions or previews for every file type. To attach files to a new message, upload them and pass the returned media IDs to post_message.

McpReactionSummary

Field	Type	Meaning
emoji	string	The emoji.
count	64-bit integer	Number of reactions with this emoji.
authorIds	string[]	The first reacting authors.

McpFoundMessage / McpFoundContact

McpFoundMessage field	Type	Meaning
chatId	string	Chat containing the match.
entryId	64-bit integer	Message local ID.
text	string	Matched text.

McpFoundContact field	Type	Meaning
kind	string	user, place or chat.
id	string	User ID, place ID or chat ID, per kind.
title	string	Name or title.

Streams

McpMessageStream

Field	Type	Meaning
streamId	string	Pass to append_message_stream and finish_message_stream.
entryId	64-bit integer	Local ID of the message being filled in.
offset	integer	Characters of text the server has accepted.
speechBacklog	number or null	Seconds of speech a listener still has to hear; null while nobody is listening.
isFinished	boolean	The stream is closed.

McpVoiceStream

Field	Type	Meaning
streamId	string	Pass to the other voice-stream tools.
entryId	64-bit integer or null	Null until finish_voice_stream returns it, and still null if nothing was posted.
textOffset	integer	Characters of text the server has accepted.
audioBytes	64-bit integer	Audio bytes received.
audioDuration	number	Seconds of audio the server has decoded.
isFinished	boolean	The stream is closed.

Uploads and chat content

McpUploadStatus

Field	Type	Meaning
uploadId	string	Upload ID.
mediaId	string or null	Media ID reserved for the upload. Null after begin_import_upload, until finish_import_upload.
offset	64-bit integer	Bytes the server has received. After finish_upload reaches Ready, equals length.
length	64-bit integer	Total length in bytes.
stage	string	Uploading, a processing stage name, or Ready.
progress	number	Percent complete for the current stage.
media	McpMediaRef or null	Set when stage is Ready.

McpMediaRef

Field	Type	Meaning
mediaId	string	Media ID to pass to other tools.
kind	string	image, video, audio or file.
fileName, contentType	string	Stored name and MIME type.
length	64-bit integer	Size in bytes.
width, height	integer	Pixel size where applicable.
url	string	Content URL.
previewUrl, thumbnailUrl	string or null	Preview and thumbnail URLs when available.

McpContentPage of T

Field	Type	Meaning
periodKey	string	Period (month) this page belongs to.
pageIndex	integer	Page within the period (0-based).
pageCount	integer	Pages in the period.
nextPeriodKey	string or null	Older period to request next; null if none.
items	T[]	McpMediaItem, McpFileItem or McpLinkItem.

McpMediaItem field	Type	Meaning
entryId	64-bit integer	Message the media belongs to.
at	64-bit integer	Time, Unix milliseconds.
mediaId, kind, fileName, contentType	string	As in McpMediaRef.
length	64-bit integer	Size in bytes.
url	string	Content URL.
thumbnailUrl	string or null	Thumbnail URL.

McpFileItem field	Type	Meaning
entryId, at	64-bit integer	Message and time.
mediaId, fileName, contentType	string	File identity.
length	64-bit integer	Size in bytes.
url	string	Content URL.

McpLinkItem field	Type	Meaning
entryId, at	64-bit integer	Message and time.
url	string	The link.
title, description	string or null	Link preview text when available.

Conversations

McpListConversationsResult / McpConversation

McpListConversationsResult has conversations (McpConversation[]) and nextBeforeId (string or null).

McpConversation field	Type	Meaning
id	string	Conversation ID.
chatId	string	Chat ID.
startEntryId, endEntryId	64-bit integer	First and last message local IDs.
startsAt, endsAt	64-bit integer	Start and end, Unix milliseconds.
title, description, summary	string	Generated title, description and summary.
messageCount, attachmentCount	integer	Counts of messages and attachments.
authorIds	string[]	Participating author IDs.

Notifications

McpListNotificationsResult / McpNotification

McpListNotificationsResult has items (McpNotification[]) and version (string): an identifier of the exact set, to pass to wait_for_notifications.

McpNotification field	Type	Meaning
id	string	Notification ID; pass it to dismiss_notification.
kind	string	Lowercase notification kind, such as message, reply, invitation, mention, reaction, attention, thread, conversation, incomingcall or speechstarted.
at	64-bit integer	Sent time, Unix milliseconds.
chatId	string or null	Related chat.
entryId	64-bit integer or null	Related message local ID.
authorId	string or null	Author who triggered it.
title, text	string	Notification title and text.
message	ExternalMessage or null	The message, if it exists and the chat is still accessible.

Import

McpImportStatus / McpImportPendingMember

get_import returns McpImportStatus. When active is false, all other fields are null.

Field	Type	Meaning
active	boolean	An import is running for the chat.
importId	string	Import ID for the other import tools.
scope	string	chat, or place for a place-wide import.
placeId	string or null	Place ID of a place-wide import.
startedBy	string or null	User ID of the owner who started it.
startedAt	64-bit integer	Start time, Unix milliseconds.
consentingCount, nonConsentingCount	integer	Members who have and have not consented.
consentPercent	number	Share of consenting members, rounded to one decimal.
myConsent	boolean	You have consented.
pending	McpImportPendingMember[] or null	Owners only: a page of members who have not consented.

McpImportPendingMember field	Type	Meaning
userId	string	User ID.
name	string	The member's avatar name.
peerChatId	string or null	Your direct chat with the member, or null if there is none.

McpImportSession / McpImportEndResult

start_import returns McpImportSession: importId, chatId, scope (chat or place), startedBy (user ID or null) and startedAt (Unix milliseconds). end_import returns McpImportEndResult with nonConsentingCount, the number of members who had not consented when the import ended.

McpImportMessage / McpImportMessagesResult

import_messages takes messages, an array of McpImportMessage:

Field	Type	Meaning
authorUserId	string	User ID of the author.
sentAt	64-bit integer	Original time, Unix milliseconds.
text	string	Message text, up to 64 KB.
replyToId	64-bit integer or null	Local ID of a message already in the chat.
uploadIds	string[] or null	Up to 10 upload IDs.

It returns McpImportMessagesResult, whose items has one entry per message in input order: id (the new local message ID, or null) and error (the reason it was rejected, or null).

Model map

get_me → McpAccount
list_avatars / create_avatar / update_avatar → McpAvatar
list_places → McpListPlacesResult → McpPlaceInfo[]
list_group_chats / list_peer_chats / list_place_chats
  → McpListChatsResult → McpChatInfo[]
get_chat / create_chat / update_chat → McpChatDetails
get_place / create_place / update_place → McpPlaceDetails
list_members / list_place_members → McpListMembersResult → McpMember[]
create_invite_link / create_place_invite_link / list_*_invite_links → McpInviteLink
get_id_range → McpIdRange<long>
list_messages → McpListMessagesResult → range, fullRange; messages: ExternalMessage[]
  ExternalMessage → ExternalAuthor, ExternalAttachment[], ExternalOrigin
list_pinned_messages → ExternalMessage[]
list_reactions → McpReactionSummary[]
post_message → long
start/append/finish_message_stream → McpMessageStream
start/append/finish_voice_stream → McpVoiceStream
begin/append/finish_upload, upload_from_url → McpUploadStatus → McpMediaRef
begin/finish_import_upload, import_upload_from_url → McpUploadStatus → McpMediaRef
get_import → McpImportStatus → McpImportPendingMember[]
start_import → McpImportSession
end_import → McpImportEndResult
import_messages → McpImportMessagesResult → items (id or error)
list_media / list_files / list_links → McpContentPage<McpMediaItem | McpFileItem | McpLinkItem>
list_conversations → McpListConversationsResult → McpConversation[]
get_conversation → McpConversation
search_messages → McpFoundMessage[]
search_contacts → McpFoundContact[]
list_notifications → McpListNotificationsResult → McpNotification[] → ExternalMessage
all other tools → no application result value

All model leaves are strings, booleans, numbers or null; no further domain models are nested behind the structures above.

Source

At d2eee636e0f13804421d2864a9575fa21ab6c940: MCP models, conversion rules, ExternalMessage and its conversion.