26 Apr
2025
26 Apr
'25
3:24 a.m.
Hello,
We've got a discussion about thread on xsf@ a couple of days ago, and I would
like to bring it here.
I initially thought that XEP-0461 (Message Replies) was redundant with
threads, except in the case where there is no thread ID in the message a user
wants to reply too. After discussion, notably with singpolyma and lovetox, it
appears that we don't have the same view on this.
The way I got it, we have basically 2 ways to see threads:
1. A series of replies to any message in a group chat, à la Slack (in Slack,
you see the replies hidden under parent message, with something like "X
replies", and when you click, a panel appear with the whole thread.
2. A side discussion explicitly started, that could be seen like a new chat
window (UI example: user clicks a "start a new thread button", and start a
blank window with it message, this message has a new thread ID, that will be
used by people replying to it).
In case 1, the parent message needs a thread ID so that thread can continue
with the same ID. Problem is if parent message doesn't has a thread ID
(because client doesn't support thread, or because there is no thread ID for
each message), in this case a XEP-0461 "reply to" can be used, then the first
reply has a new thread ID, and the thread can continue.
In case 2, the explicitly started thread has a newly generated thread ID, so
there is no problem.
I want to support both 1 and 2. For 1, my initial reading of XEP-0201 (Best
Practices for Message Threads) was that a new thread ID should be generated
for each message:
Unless a <message/> stanza is written in direct
reply to another <message/>
stanza, if a ThreadID is included then its value SHOULD be newly generated
when a human user initiates a chat conversation with another user (i.e., a
<message/> stanza of type 'chat'), starts a new conversation in the
context
of a multi-user chat environment (i.e., a <message/> stanza of type
'groupchat'), or sends a normal message.
XEP-0201 §3.2.
But after discussion, I realise that it's not requested to generate a new ID
each time, and it seems that generating new thread ID for each message would
be a problem for some clients (notably Cheogram which would create a thread UI
for each ID).
The solution would be to use "reply to" from XEP-0461, then a newly generated
thread ID.
I've also proposed an alternative when parent message ID could be used as
thread ID, this may we can find parent message without relying on XEP-0461.
For the moment, I think that I won't generate new thread ID for each message,
and if I create a thread from a parent message I'll use a XEP-0461 "reply
to"
and generate a new thread ID, then use this thread ID for following message in
this thread.
However, I would like to have feedback from the wider community:
- how to you handle or plan to handle threads?
- Are you planning to implement case 1 (threads can be started from any
message) and/or case 2 (threads are explicitly started)?
- How would you handle case 1?
Thanks!
Best,
Goffi
26 Apr
26 Apr
4:26 a.m.
Hi,
The one thing that bugs me about the reply method is, that it depends on that i go
searching first if someone else has replied to be able to send a message.
This leads to the situation that multiple threads are created if different people answer
nearly at the same time. At this point its unclear how to go forward. Certainly the two
people didn't want to have separate threads.
Further stuff like moderate can remove all content from a message, it would destroy the
link to the parent message if the first reply gets moderated. Leaving all other messages
hanging in the air without context.
So for me the thread string needs to be generated out of the parent message to avoid this,
and also make it simple.
If for some reason the community deems it absolute necessary to create threads from
messages that don't have a thread themself s, i would simply take the message-id of
the parent message and use it as a thread id, circumventing any mentioned problems above.
This is even moderate safe, because the message-id is never moderated.
This comes at the cost of losing the feature to signal that a message should not be used
for a thread.
Regards
Philipp
On Sat, Apr 26, 2025, at 11:24, Goffi wrote:
Hello,
We've got a discussion about thread on xsf@ a couple of days ago, and I would
like to bring it here.
I initially thought that XEP-0461 (Message Replies) was redundant with
threads, except in the case where there is no thread ID in the message a user
wants to reply too. After discussion, notably with singpolyma and lovetox, it
appears that we don't have the same view on this.
The way I got it, we have basically 2 ways to see threads:
1. A series of replies to any message in a group chat, à la Slack (in Slack,
you see the replies hidden under parent message, with something like "X
replies", and when you click, a panel appear with the whole thread.
2. A side discussion explicitly started, that could be seen like a new chat
window (UI example: user clicks a "start a new thread button", and start a
blank window with it message, this message has a new thread ID, that will be
used by people replying to it).
In case 1, the parent message needs a thread ID so that thread can continue
with the same ID. Problem is if parent message doesn't has a thread ID
(because client doesn't support thread, or because there is no thread ID for
each message), in this case a XEP-0461 "reply to" can be used, then the first
reply has a new thread ID, and the thread can continue.
In case 2, the explicitly started thread has a newly generated thread ID, so
there is no problem.
I want to support both 1 and 2. For 1, my initial reading of XEP-0201 (Best
Practices for Message Threads) was that a new thread ID should be generated
for each message:
Unless a <message/> stanza is written in
direct reply to another <message/>
stanza, if a ThreadID is included then its value SHOULD be newly generated
when a human user initiates a chat conversation with another user (i.e., a
<message/> stanza of type 'chat'), starts a new conversation in the
context
of a multi-user chat environment (i.e., a <message/> stanza of type
'groupchat'), or sends a normal message.
XEP-0201 §3.2.
But after discussion, I realise that it's not requested to generate a new ID
each time, and it seems that generating new thread ID for each message would
be a problem for some clients (notably Cheogram which would create a thread UI
for each ID).
The solution would be to use "reply to" from XEP-0461, then a newly generated
thread ID.
I've also proposed an alternative when parent message ID could be used as
thread ID, this may we can find parent message without relying on XEP-0461.
For the moment, I think that I won't generate new thread ID for each message,
and if I create a thread from a parent message I'll use a XEP-0461 "reply
to"
and generate a new thread ID, then use this thread ID for following message in
this thread.
However, I would like to have feedback from the wider community:
- how to you handle or plan to handle threads?
- Are you planning to implement case 1 (threads can be started from any
message) and/or case 2 (threads are explicitly started)?
- How would you handle case 1?
Thanks!
Best,
Goffi
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• signature.asc
4:53 a.m.
Hi Philipp, thanks for your feedback.
Le samedi 26 avril 2025, 12:26:47 heure d’été d’Europe centrale Philipp Hörist
a écrit :
The one thing that bugs me about the reply method is,
that it depends on
that i go searching first if someone else has replied to be able
to send a
message.
This leads to the situation that multiple threads are created if different
people
answer nearly at the same time. At this point its unclear how to go
forward. Certainly the two people didn't want to have separate threads.
I don't see that it's needed to check for other replies. If two people start a
reply at the same time, there will be two threads with the same parent, in the
UI this appears like a tree, i stays readable. This is what happens on sites
like Reddit on ActivityPub (but on Mastodon, the tree doesn't appear in
comments, making it very confusing IMO).
Further stuff like moderate can remove all content
from a message, it would
destroy the link to the parent message if the first reply
gets moderated.
Leaving all other messages hanging in the air without context.
Indeed, that's a problem if the first reply with the new thread ID is deleted,
good point.
So for me the thread string needs to be generated out
of the parent message
to avoid this, and also make it simple.
If for some reason the community deems it absolute necessary to create
threads
from messages that don't have a thread themself s, i would simply take
the message-id of the parent message and use it as a thread id, circumventing
any mentioned problems above. This is even moderate safe, because the message-
id is never moderated.
Yeah, that's the alternative that I have proposed. I think that using parent
message ID as thread ID is a good option, maybe with a XEP to explain this
behaviour. This can be used at the same time as XEP-0461, so clients
implementing only XEP-0461 can still see it as a reply (but XEP-0461 says that
it should not be used for sub-thread, so if other replies are made using
XEP-0461, it may be a problem).
This comes at the cost of losing the feature to signal
that a message should
not be used for a thread.
How do you signal that a message should not be used for a thread, and why
would you do that?
From a UX point of view, I think that it would be bad that some messages can
be replied in a thread, and some other can't, the end-user would not
understand why sometime the button appears, and sometimes not.
Best,
Goffi
4:57 a.m.
[sorry my previous message was badly formatted, I send it again to make it more readable]
Hi Philipp, thanks for your feedback.
Le samedi 26 avril 2025, 12:26:47 heure d’été d’Europe centrale Philipp Hörist
a écrit :
The one thing that bugs me about the reply method is,
that it depends on
that i go searching first if someone else has replied to be able to send a
message.
This leads to the situation that multiple threads are created if different
people answer nearly at the same time. At this point its unclear how to go
forward. Certainly the two people didn't want to have separate threads.
I don't see that it's needed to check for other replies. If two people start a
reply at the same time, there will be two threads with the same parent, in the
UI this appears like a tree, i stays readable. This is what happens on sites
like Reddit on ActivityPub (but on Mastodon, the tree doesn't appear in
comments, making it very confusing IMO).
Further stuff like moderate can remove all content
from a message, it would
destroy the link to the parent message if the first reply gets moderated.
Leaving all other messages hanging in the air without context.
Indeed, that's a problem if the first reply with the new thread ID is deleted,
good point.
So for me the thread string needs to be generated out
of the parent message
to avoid this, and also make it simple.
If for some reason the community deems it absolute necessary to create
threads from messages that don't have a thread themself s, i would simply take
the message-id of the parent message and use it as a thread id, circumventing
any mentioned problems above. This is even moderate safe, because the message-
id is never moderated.
Yeah, that's the alternative that I have proposed. I think that using parent
message ID as thread ID is a good option, maybe with a XEP to explain this
behaviour. This can be used at the same time as XEP-0461, so clients
implementing only XEP-0461 can still see it as a reply (but XEP-0461 says that
it should not be used for sub-thread, so if other replies are made using
XEP-0461, it may be a problem).
This comes at the cost of losing the feature to signal
that a message should
not be used for a thread.
How do you signal that a message should not be used for a thread, and why
would you do that?
From a UX point of view, I think that it would be bad that some messages can
be replied in a thread, and some other can't, the end-user would not
understand why sometime the button appears, and sometimes not.
Best,
Goffi
5:17 a.m.
Hi,
On Sat, Apr 26, 2025, at 12:57, Goffi wrote:
I just wanted to note what the implications are of the design decision. I could imagine
someone wanting in their channel that no thread is created under a bot message. I dont see
this as a show stopper, just want to prevent that in a year we need to add
<no-thread> for some reason, when we could have it now naturally by not including a
thread.
As for the moderation XEP, i definitely think the moderation and als retraction XEP should
exclude the <thread> element from being removed, from the message.
Regards
Philipp
I don't see that it's needed to check for
other replies. If two people start a
reply at the same time, there will be two threads with the same parent, in the
UI this appears like a tree, i stays readable. This is what happens on sites
like Reddit on ActivityPub (but on Mastodon, the tree doesn't appear in
comments, making it very confusing IMO).
Never used those services, but the normal flow i imagine is, im in a support channel,
someone asks a question "How do i do X?", now 2 people start to type, and create
two separate threads with the answer, now a 4. person wants to join, then the client needs
to decide to reply to one of the threads.
Also from the GUI side its unclear how should handle this, should i hide the fact that
there are 2 threads? Should i show 2 threads? But then obviously both users wanted to
answer the same person, i would say it would be the expectation that this conversation is
wrapped in a single thread and not multiple.
But maybe i envision this worse than it is in practice.
This comes at
the cost of losing the feature to signal that a message should
not be used for a thread.
How do you signal that a message should not be used for a thread, and why
would you do that?
From a UX point of view, I think that it would be bad that some messages can
be replied in a thread, and some other can't, the end-user would not
understand why sometime the button appears, and sometimes not. 
27 Apr
27 Apr
1:26 a.m.
Hi,
Adding a few design notes from my experience with other platforms.
Hopefully this will help inform further discussion.
> I don't see that it's needed to check for
other replies. If two
> people start a
> reply at the same time, there will be two threads with the same
> parent, in the
> UI this appears like a tree, i stays readable. This is what happens
> on sites
> like Reddit on ActivityPub (but on Mastodon, the tree doesn't appear in
> comments, making it very confusing IMO).
ActivityPub uses the concept of "parent post" rather than "threads".
And
yes, it does get confusing when the replies branch out into a tree and
then get "flattened" out for display in interfaces like Mastodon's.
If I want to choose a single strand of the conversation, I would choose
the last post in that sequence, and then get presented with all direct
ancestors of that post (which is a single strand as each child can only
have one parent). I think this "single linear sequence, among possibly
many", is what originally became Twitter-style "threads" (now used by
Mastodon too).
In summary: AP "threads" are basically "a sequence of posts where each
post is a child of the immediately preceding one", but as each original
post can branch out into many "threads" I'd say it's more of a GUI
consideration than anything else.
Never used those services, but the normal flow i
imagine is, im in a
support channel, someone asks a question "How do i do X?", now 2
people start to type, and create two separate threads with the answer,
now a 4. person wants to join, then the client needs to decide to
reply to one of the threads.
Also from the GUI side its unclear how should handle this, should i
hide the fact that there are 2 threads? Should i show 2 threads? But
then obviously both users wanted to answer the same person, i would
say it would be the expectation that this conversation is wrapped in a
single thread and not multiple.
What happens in AP in practice is that the third commenter would make
another reply that is a direct child of the original post (yet another
"thread" if you will). People also use it in this way; if I wanted to
reply specifically to Commenter 1 I would reply to Commenter 1's post,
but if I wanted to make a general comment on the entire conversation I
would reply directly to the main thread.
This is very different from how I would approach interacting with a
conversation in a chat-oriented app (XMPP or otherwise): on ActivityPub
I'm more diligent about selecting the specific message I want to reply
to. I think that's partly because each reply is a "post" in its own
right that could be shared, boosted, etc. and show up on peoples'
timelines as an entry point to whatever they're going to see next.
Depending on which message I reply to, they'd be presented with a
different view of the conversation (which they could change, of course,
but it is their first view of the entire conversation).
Finally, with regard to moderation/retraction: with ActivityPub software
(including Akkoma and Mastodon), when I'm deleting a post I get a
warning that any replies to that post will be "orphaned", i.e. not have
a parent any more. I have also seen some posts where in place of a
parent all I get is "this post no longer exists". So it is arguably an
issue there as well (but see my next section with thoughts about threads).
------------------------------------------------------------------------
On a different note, since there was some debate about how to include
thread IDs: Discord, unlike AP, treats "threads" and "a sequence of
replies" as two different things. The default mode is to have all the
conversation inline (no threads/parents/etc.) but if there's a sequence
of replies (a message, to which there is a reply, to which there is
another reply) then it asks if I want to "convert that message to a
thread". (One can decide to make a message into a thread at any point,
but the UX explicitly suggests it when it thinks a sequence of replies
has gone on for long enough)
At that point, only the parent message will be shown in the main message
area and subsequent replies (which are all linear/sequential) show up
only when you click on that parent message to navigate into the thread.
Mattermost, on the other hand, does "both" which I suppose is somewhat
similar to Mastodon. Replies are internally a "tree of replies", but the
default view is to show only the first message and make the user click
through to see the other replies in a linear way (so, visually similar
to Discord "threads").
However, there is also an option to turn off "threads mode" at which
point all the child replies will show up along with the main messages
(visually similar to Discord "replies"). In this mode clicking on any of
the child messages will show up the entire "thread" (i.e. initial parent
message and all it's descendant replies).
In my opinion Mattermost is the most confusing as people experience the
messages differently depending on their settings. For XMPP, perhaps we
should first decide which of "linear threads" or "branching-out
replies"
is being defined? Even if we have both, in my opinion it would be better
to treat them as separate (if somewhat related) concepts. Linear threads
would be the ones with thread IDs whereas "branching out replies" don't
need to have anything to do with threads at all.
After typing the above, I realised that Goffi had outlined these
different modes of thinking too; I am pasting a quote for reference:
The way I got it, we have basically 2 ways to see
threads:
1. A series of replies to any message in a group chat, à la Slack (in Slack,
you see the replies hidden under parent message, with something like "X
replies", and when you click, a panel appear with the whole thread.
2. A side discussion explicitly started, that could be seen like a new chat
window (UI example: user clicks a "start a new thread button", and start a
blank window with it message, this message has a new thread ID, that will be
used by people replying to it).
As I said, I think it would be best to treat these as two separate
features, and either decide which we want or do as Discord does and
offer each as distinct options.
Best,
Badri
2:22 a.m.
Thanks for your post it's interesting to see how things are handled across software.
Just a side note: whatever we choose, we have to consider gateways. Somehow somebody will
have to convert third party network behaviour to XMPP one.
So I'm in favor of some flexibility. The challenge is to have it while keeping UX
acceptable, and not confusing when we switch XMPP client.
Le 27 avril 2025 09:26:46 GMT+02:00, Badri Sunderarajan <badrihippo(a)disroot.org> a
écrit :
Hi,
Adding a few design notes from my experience with other platforms. Hopefully this will
help inform further discussion.
> I don't see that it's needed to check
for other replies. If two people start a
> reply at the same time, there will be two threads with the same parent, in the
> UI this appears like a tree, i stays readable. This is what happens on sites
> like Reddit on ActivityPub (but on Mastodon, the tree doesn't appear in
> comments, making it very confusing IMO).
ActivityPub uses the concept of "parent post" rather than "threads".
And yes, it does get confusing when the replies branch out into a tree and then get
"flattened" out for display in interfaces like Mastodon's.
If I want to choose a single strand of the conversation, I would choose the last post in
that sequence, and then get presented with all direct ancestors of that post (which is a
single strand as each child can only have one parent). I think this "single linear
sequence, among possibly many", is what originally became Twitter-style
"threads" (now used by Mastodon too).
In summary: AP "threads" are basically "a sequence of posts where each post
is a child of the immediately preceding one", but as each original post can branch
out into many "threads" I'd say it's more of a GUI consideration than
anything else.
Never used those services, but the normal flow i
imagine is, im in a support channel, someone asks a question "How do i do X?",
now 2 people start to type, and create two separate threads with the answer, now a 4.
person wants to join, then the client needs to decide to reply to one of the threads.
Also from the GUI side its unclear how should handle this, should i hide the fact that
there are 2 threads? Should i show 2 threads? But then obviously both users wanted to
answer the same person, i would say it would be the expectation that this conversation is
wrapped in a single thread and not multiple.
What happens in AP in practice is that the third commenter would make another reply that
is a direct child of the original post (yet another "thread" if you will).
People also use it in this way; if I wanted to reply specifically to Commenter 1 I would
reply to Commenter 1's post, but if I wanted to make a general comment on the entire
conversation I would reply directly to the main thread.
This is very different from how I would approach interacting with a conversation in a
chat-oriented app (XMPP or otherwise): on ActivityPub I'm more diligent about
selecting the specific message I want to reply to. I think that's partly because each
reply is a "post" in its own right that could be shared, boosted, etc. and show
up on peoples' timelines as an entry point to whatever they're going to see next.
Depending on which message I reply to, they'd be presented with a different view of
the conversation (which they could change, of course, but it is their first view of the
entire conversation).
Finally, with regard to moderation/retraction: with ActivityPub software (including Akkoma
and Mastodon), when I'm deleting a post I get a warning that any replies to that post
will be "orphaned", i.e. not have a parent any more. I have also seen some posts
where in place of a parent all I get is "this post no longer exists". So it is
arguably an issue there as well (but see my next section with thoughts about threads).
------------------------------------------------------------------------
On a different note, since there was some debate about how to include thread IDs: Discord,
unlike AP, treats "threads" and "a sequence of replies" as two
different things. The default mode is to have all the conversation inline (no
threads/parents/etc.) but if there's a sequence of replies (a message, to which there
is a reply, to which there is another reply) then it asks if I want to "convert that
message to a thread". (One can decide to make a message into a thread at any point,
but the UX explicitly suggests it when it thinks a sequence of replies has gone on for
long enough)
At that point, only the parent message will be shown in the main message area and
subsequent replies (which are all linear/sequential) show up only when you click on that
parent message to navigate into the thread.
Mattermost, on the other hand, does "both" which I suppose is somewhat similar
to Mastodon. Replies are internally a "tree of replies", but the default view is
to show only the first message and make the user click through to see the other replies in
a linear way (so, visually similar to Discord "threads").
However, there is also an option to turn off "threads mode" at which point all
the child replies will show up along with the main messages (visually similar to Discord
"replies"). In this mode clicking on any of the child messages will show up the
entire "thread" (i.e. initial parent message and all it's descendant
replies).
In my opinion Mattermost is the most confusing as people experience the messages
differently depending on their settings. For XMPP, perhaps we should first decide which of
"linear threads" or "branching-out replies" is being defined? Even if
we have both, in my opinion it would be better to treat them as separate (if somewhat
related) concepts. Linear threads would be the ones with thread IDs whereas
"branching out replies" don't need to have anything to do with threads at
all.
After typing the above, I realised that Goffi had outlined these different modes of
thinking too; I am pasting a quote for reference:
The way I got it, we have basically 2 ways to see
threads:
1. A series of replies to any message in a group chat, à la Slack (in Slack,
you see the replies hidden under parent message, with something like "X
replies", and when you click, a panel appear with the whole thread.
2. A side discussion explicitly started, that could be seen like a new chat
window (UI example: user clicks a "start a new thread button", and start a
blank window with it message, this message has a new thread ID, that will be
used by people replying to it).
As I said, I think it would be best to treat these
as two separate features, and either decide which we want or do as Discord does and offer
each as distinct options.
Best,
Badri
30 Apr
30 Apr
4:30 a.m.
Hi,
On Sat, 2025-04-26 at 12:57 +0200, Goffi wrote:
but XEP-0461 says that
it should not be used for sub-thread, so if other replies are made
using
XEP-0461, it may be a problem
To clarify on this:
XEP-0461 was meant to be used exclusively for replying to a message,
not to indicate any thread logic or anything similar. Replies are meant
to show in the "main" timeline (not a sub-thread) and two replies to
the same message are not meant to have any direct relation with each
other.
The purpose of XEP-0461 was to clean-up/standardize on something that
was done in the wild: Users (and some clients) used "quote reply" to a
message, meaning to copy the entire contents of a previous message as a
blockquote in a new message and then write below that, indicating this
is a reply to that previous message. XEP-0461 allows to do that in a
way that is understood properly by clients (allowing to link to the
original message or show extra details about the original message). It
also makes it possible to extend this functionality to non-textual
message (file share).
In other words, XEP-0461 is the equivalent of the reply feature you can
see in WhatsApp or Telegram and is completely adjacent to threads in
the style of Slack, Zulip or Cheogram.
Marvin
26 Apr
26 Apr
5:14 a.m.
On 2025-04-26 12:26, Philipp Hörist wrote:
If for some reason the community deems it absolute
necessary to create
threads from messages that don't have a thread themself s, i would
simply take the message-id of the parent message and use it as a
thread id, circumventing any mentioned problems above. This is even
moderate safe, because the message-id is never moderated.
This comes at the cost of losing the feature to signal that a message
should not be used for a thread.
While I don't have any preference for one or the other solution, the
latter could be signalled explicitely. Might need a new XEP, though.
On Sat, Apr 26, 2025, at 11:24, Goffi wrote:
2. A side discussion explicitly started, that could
be seen like a new chat
window (UI example: user clicks a "start a new thread button", and start a
blank window with it message, this message has a new thread ID, that will be
used by people replying to it).
In my experience, this is not how humans work.
People will just reply, and not care about any change of subject.
That's what is happening with email all of the time :-(
Cheers
5
days inactive
9
days old
8 comments
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Martin -
Marvin W -
Philipp Hörist