Gateway threads

A session receives threads through the Dispatch events below. A guild ready object in Ready, Guild Create, and Guild Sync has threads only for a session with thread access.

User sessions need the CHANNEL_THREADS session flag

A user session has thread access only when it sets CHANNEL_THREADS in Identify. A bot session always has thread access and needs no flag. HTTP routes read a separate client capability, as Client capability describes.

Session flag

Value	Name	Description
1 << 2	CHANNEL_THREADS	The client can parse thread, forum, and media channels

The flag joins the session flags of Identify. A user session without it receives no channel of type 10, 11, 12, 15, or 16 and no event from this page. Its guild ready objects leave out a category that is visible only through a forum or media channel inside it. Its channels have no flags and no thread or forum fields. Its roles and permission overwrites have the thread permission bits cleared. Ready leaves out every read state that has flags. It receives no Message ACK for an entry that has flags. It receives no Channel Pins ACK for a thread and no Saved Message Create for a message in a thread.

The same session receives no message of type 18 (THREAD_CREATED) or 21 (THREAD_STARTER_MESSAGE). Its messages have no thread field. The message flags HAS_THREAD (1 << 5) and FAILED_TO_MENTION_SOME_ROLES_IN_THREAD (1 << 8) are cleared.

Guild threads

threads on a guild ready object is an array of thread objects. A user session receives the active threads it joined and can view, each with member. A bot session receives every active thread it can view, with member on the threads it joined.

The member of each entry has no id, user_id, member, or presence. A thread object in a guild ready object or in any event on this page has no member_ids_preview.

Dispatch events

Event	Description	Scope
Thread Create	A thread is created or the session joins one	Thread visibility
Thread Update	A visible thread changes	Thread visibility
Thread Delete	A thread is deleted	Thread visibility
Thread List Sync	The session’s active thread set is replaced	Guild connection
Thread Member Update	The session’s own thread membership changes	Current user
Thread Members Update	Users join or leave a thread	Thread visibility
Thread Member List Update	A subscribed thread member list resyncs	Member list subscription
Forum Unreads	Unread counts for forum posts are returned	Command response

A passive session in a guild with more than 250 members receives fewer thread events, as each event states.

Messages, reactions, typing, and pins in a thread reach a session that can view the thread and meets one of these conditions. An event in the message access set of Event filtering also needs message access in the thread. These events also follow Active and passive guilds.

• The session is a bot session.
• The user is a member of the thread.
• The session lists the thread in thread_member_lists.
• The session set threads and the guild is active for it, through Lazy Request active or the Identify initial_guild_id, whatever the guild size.

Message Create in a thread has channel_type set to the thread type.

THREAD_CREATE

A thread was created, or the session was added to one. The payload is the thread object with the fields below.

Field	Type	Description
newly_created?	boolean	Always true, present only when the thread was just created
member?	thread member object	The session’s own membership, present only for a member

Recipients are the sessions that can view the thread and are a bot session, a member, or a session that set threads through Lazy Request. A passive session in a guild with more than 250 members receives it only when its user is a member.

A user added to an existing thread receives a Thread Create with member and no newly_created. It arrives before the matching Thread Members Update.

THREAD_UPDATE

A thread changed. The payload is the thread object.

Recipients are the sessions that can view the thread and are a bot session, a member, or a session that set threads. Fluxer checks them before and after the change and sends to both sets. A passive session in a guild with more than 250 members receives it only for a thread it joined.

A message sent to an archived thread unarchives it and emits Thread Update. A message sent to an active thread emits none. When a thread is unarchived, each session of a member that can view it also receives a Thread Member Update.

THREAD_DELETE

A thread was deleted.

Field	Type	Description
id	snowflake	The ID of the thread
guild_id	snowflake	The ID of the guild
parent_id	snowflake	The ID of the parent channel
type	integer	The thread type

Recipients are the sessions that can view the thread as it stood before the deletion and are a bot session, a member, or a session that set threads. A member is a user the guild holds as a member of the thread, or one of up to 1,000 thread members Fluxer reads at deletion. A passive session in a guild with more than 250 members receives it only when its user is a member.

THREAD_LIST_SYNC

The session’s active threads were replaced for a guild or for some of its channels.

Field	Type	Description
guild_id	snowflake	The ID of the guild
channel_ids?1	array[snowflake]	The parent channels whose threads are replaced
threads2	array[thread object]	The active threads the session can view
members	array[thread member object]	The session’s memberships in those threads

¹ Absent when the event replaces every thread in the guild

² With channel_ids, every active thread in those channels. Without it, every active thread in the guild for a bot session and for a session that set threads

Without channel_ids, a user session that did not set threads receives the active threads it joined.

• Fluxer sends it when Lazy Request sets threads to true for a session that had not set it. The event follows after a random delay below 5,000 ms.
• Fluxer sends it when the guild reloads its thread state. A bot session, a session that set threads, and a user session that joined an active thread each receive one.
• Fluxer sends it when the session gains view access to channels that have active threads. channel_ids lists those channels.

A guild sends a burst of up to 20 full syncs, then 20 more each second, and queues the rest. Thread List Sync is delivered live and never retained for Resume.

THREAD_MEMBER_UPDATE

The session’s own membership in a thread changed. The payload is the thread member object with guild_id. It has muted and mute_config.

Every session of the user that can view the thread receives it, passive or not.

THREAD_MEMBERS_UPDATE

Users joined or left a thread.

Field	Type	Description
id	snowflake	The ID of the thread
guild_id	snowflake	The ID of the guild
member_count	integer	The number of thread members, capped at 50
added_members?1	array[thread member object]	The users who joined
removed_member_ids?	array[snowflake]	The IDs of the users who left

¹ Each entry has no muted or mute_config, and adds member and presence

member is the guild member, or null when the guild has none for the user. presence is the presence object with user reduced to id, or null when the user is not visibly online to the guild.

Every session of an added or removed user receives it. Any other session receives it when it can view the thread and is a bot session, a member, or a session that set threads. A passive session in a guild with more than 250 members receives it only when its user was added or removed.

THREAD_MEMBER_LIST_UPDATE

A thread member list the session subscribed to through thread_member_lists resynced.

Field	Type	Description
guild_id	snowflake	The ID of the guild
thread_id	snowflake	The ID of the thread
members1	array[thread member list item object]	The members of the thread, at most 1,000

¹ Each item is user_id, join_timestamp, flags, member, and presence

member is the guild member or null. presence is the guild’s presence object when the user is visibly online to the guild, and otherwise the placeholder {"status": "offline", "mobile": false, "afk": false}.

The event is delivered live and never retained for Resume.

FORUM_UNREADS

The answer to Request Forum Unreads.

Field	Type	Description
guild_id	snowflake	The ID of the guild
channel_id	snowflake	The ID of the forum or media channel
threads	array[forum unread object]	One entry for each requested post found in the channel

Each forum unread object is thread_id with either count or missing. count is the number of messages after the sent ack_message_id, capped at 25. missing is true when the request sent no valid ack_message_id for that post.

Lazy Request thread options

The guild subscription object of Lazy Request takes two more options. Fluxer applies them after typing.

Field	Type	Description
threads?	boolean	Whether the session receives events and messages for every thread it can view in the guild
thread_member_lists?	array[snowflake]	The threads whose member lists the session subscribes to, at most 10

Fluxer ignores both options for a user session that did not set CHANNEL_THREADS. threads set to false clears the subscription, and any value that is not a Boolean is ignored. Fluxer also clears it when the session marks the guild passive.

thread_member_lists replaces the previous list, and an empty array clears it. Fluxer keeps the first 10 entries that are Snowflakes and removes duplicates. It then drops each thread the session cannot view or that is not active. A value that is not an array is ignored.

Each newly listed thread produces a Thread Member List Update at once. A membership change in the thread, or a presence change of one of its listed members, produces another after a 250 ms batching delay.

Request Forum Unreads

Opcode 28 requests unread counts for posts in one forum or media channel.

Field	Type	Description
guild_id	snowflake	The ID of the guild
channel_id	snowflake	The ID of the forum or media channel
threads	array[forum unread request object]	The posts to count, deduplicated and truncated to 40

Each forum unread request object is thread_id and an optional ack_message_id, the newest message the client has read in that post. An entry with no valid thread_id is dropped. An ack_message_id that is not a valid Snowflake counts as absent.

{
  "op": 28,
  "d": {
    "guild_id": "1189375284394692608",
    "channel_id": "1189375284394692700",
    "threads": [{"thread_id": "1189375284394692800", "ack_message_id": "1189375284394692900"}]
  }
}

Results arrive in one Forum Unreads. A post that does not exist or is outside the channel has no entry. An archived post, and an active post that has a message after the sent ack_message_id, has no entry when Fluxer fails to count its messages.

No Dispatch follows in these cases.

• The guild or channel ID is not a valid Snowflake.
• The guild is not connected to the session.
• The channel is not a forum or media channel.
• The session cannot view the channel.
• The request has no valid thread_id.
• The connection has too many requests in progress.

A user session that did not set CHANNEL_THREADS closes with 4001 and reason Unknown opcode. A d that is not an object closes the same way.

Request Forum Unreads accepts five commands per WebSocket in a rolling 5-second window. A further command is discarded without closing the connection.