channels: let subscribers send reactions

[r10s]

this issue is about to allow sending reactions from subscriber to channel owner.

the reactions will not be distributed to all other subscribers - this can be considered in a follow up - but already without, this has the advantage of the channel owder to get some feedback.

distribution, as well as other things as a whitelist of reactions are out of scope for now

cmp #7678, #7679

cc @Hocuri

[Hocuri]

This may be confusing to people, who expect that reactions are distributed to all subscribers, because that's how WhatsApp and Telegram implement it. And it may look like a bug that only the channel owner sees reactions. Maybe it's fine, but still, I would tend just not to allow reactions at all.

FTR, distributing reactions to all subscribers would be questionable usable-security-wise, although this is out of scope for the issue here, anyways ¹.

Footnotes

1. • Reactions in channels are a social-media feature, which is not the direction we want Delta Chat to go to. I.e. it shows you "this message is good and important and trustworthy because 100 other people also trust it". We want our users to judge channels by the quality of the messages, not by the mass hype that comes with them.
   • Even worse, it would be easy for the channel operator to fake the reaction counts, creating a false sense of trustworthyness, and making it easier to scam people.
   ↩

[r10s]

i agree, that this issue is no no-brainer as #7678 and #7679

btw, there was another idea around i forgot to file an issue for: showing the number of read receipts to the channel owner, directly in the bubbles. that would also already improve the "feedback" aspect mentioned above

[hpk42]

I think it does make sense to let channels become more interactive. At least i am not on board to rule out relaying reactions to subscribers on just the basis of "it's too much like social media and thus bad".

[Hocuri]

I like the idea of showing the number of read receipts directly in the bubbles 👍.

At least i am not on board to rule out relaying reactions to subscribers on just the basis of "it's too much like social media and thus bad".

Let me phrase my argument in another way, then. Seeing how many people liked a post is a feature that most social media apps have, and it's creating problems:

• People decide by the number of likes how much a post is "worth" and how trustworthy it is.
• Therefore, content creators try to get these numbers up. Concretely, ragebait content and people buy likes.

Also, the question is why we would want subscribers to see other's reactions? Like, what's the relevant info we're giving to users?

I assume that most users who ask for it will want to use it in order to judge a post's trustworthiness, but since they can easily be faked, this is not good.

[adbenitez]

I think federating reactions would be fine, people can always be tricked in many ways, you can anyways buy likes and followers in Instagram and other social media, people are already doing that, so I will not consider this a reason for not to have reactions in delta chat channels

I think the main problem here is restricting the allowed reactions, ex. only allow the default emoji reactions we offer, and not blindly trust reactions because attacker can send arbitrary text as reaction ex "fuck-you", "child-porn" etc., another problem is a DoS attack by reacting constantly (potentially even with big reaction payload) and using the channel owner's device to spam all subscribers with a lot of (potentially big) messages and fill their inbox etc

so blindly forwarding to all subscribers in real time whatever some subscriber send us is not good, this DoS part also applies to forwarding webxdc updates btw

[hpk42]

On Wed, Jan 07, 2026 at 08:12 -0800, Hocuri wrote: > At least i am not on board to rule out relaying reactions to subscribers on just the basis of "it's too much like social media and thus bad". Let me phrase my argument in another way, then. Seeing how many people liked a post is a feature that most social media apps have, and it's creating problems: - People decide by the number of likes how much a post is "worth" and how trustworthy it is. - Therefore, content creators try to get these numbers up. Concretely, ragebait content and people buy likes. Also, the question is why we would want subscribers to see other's reactions? Like, what's the relevant info we're giving to users?

Telegram channels allow interactivity between recipients through reactions; barring subscribers from noticing anything about other subscribers limits the experience. Honest broadcast senders can use it to ask questions poll-style, or otherwise notice what their subscribers like. It's not all bad. Cheating with imaginery reactions (a 1000 likes or so) is possible only if the sender uses a hacked version of delta chat. It's a valid concern but needs to be balanced with providing a close-to-TG experience IMHO.

[Simon-Laux]

I would also say that users expect to be able to react in a channel.
I personally think public view count could be more harmful (socially) than reactions, but we don't plan to have channel discovery with an algorithm that favors more interaction, so I doubt that these things have that much of an impact in our case.

Telegram seems to limit the reactions you can send in a channel to 5 different ones.
I believe this this makes sense because otherwise you'll have the "discord" problem that there can be many rows of reactions, like there is not enough space on screen for all different reactions if there is no limit.

But federation will need more considerations anyway, like an alternative data field to get reaction count from, where reaction is not linked to a contact and where reactions are batched, like we probably don't want to send 5000 reaction messages to everyone, when we can send just one message which summarizes the current numbers of reactions.
And changes to UI as channel subscribers will not be able to see who reacted, so opening the reaction info dialog should not be done (unless it also supports reactions without senders).

[iequidoo]

Whatever is discussed here, sending reactions to the channel owner (i.e. what the issue suggests) looks as a useful feedback. To make it less confusing, "React" can be renamed to "React privately" in channels. I'd say it's more boring than confusing, but anyway doesn't make channels worse