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Looks really nice, thank you for open-sourcing. I keep a directory of opensource alternatives. Would you say this is a Discord or Slack alternative?
In terms of inspiration and also the market that I want to go after with Chatto Cloud, this is definitely aiming to be an alternative to Slack, Teams, Mattermost et al. I've tried to make it friendly and casual enough to _also_ work as a Discord alternative, though.
Amazing. And with SSO out of the box without weird "Oh, SSO is Enterprise only" BS.
Ah mobile app is not ready yet. I am looking for some alternative to matrix because running it with bots is a bit convoluted, i.e. you have to have limit of edits of message for model streaming or you will kill entire room. Or I never seen robots in matrix sending encrypted messages. Why bother than? Anyway if mobile will be a thing this seems like perfect thing to have for your family and friends.
I’ve known Hendrik for years, and he is one of the most talented developers I’ve ever met. I’m confident this project will become successful very quickly. Beyond the project itself, what fascinates me most is how he single-handedly developed it by leveraging agentic coding.
> It’s designed to be extremely easy to self-host on your own infrastructure.

Kudos for this. Per the docs: https://docs.chatto.run/,

> Chatto ships in a compact, self-contained binary

> it uses NATS, a compact message broker that also ships with a built-in stream persistence engine [...] NATS is just as easy to provision as Chatto, and most of our examples will show you how.

> you can also configure an external S3-compatible object storage for Chatto to store your files in, and we strongly recommend doing so...

> The actual calls are powered by LiveKit (Apache-2.0), which you need to deploy alongside Chatto. As with NATS, the deployment examples show the required wiring.

> ...

And kudos for backing it up with real guidance. Great project.

looks like a great project, want to get AI bots talking to each other
Would English speakers pronounce this as "Chat-to"? To a Japanese person, this clearly sounds like "Cha-tto," which simply means "chat."
> And you can just self-host it. For free, too! (A weird thing to write, but the OSS chat app space has become very weird in many ways!)

Wait, what? There are open-source chat apps that you have to pay to host yourself? How does that work? Or did I misunderstand?

This is awesome! Some feedback - I can't tell anywhere from the website if there is mobile support (which is a must-have if I want to consider moving my company or friends over to this)
Chatto currently commits to providing a strong PWA experience that also works great on mobile (including full support for voice and video calls, push notifications, the works.)

I am aware though that a lot of people would prefer an app that they can install, so this will be coming at some point -- just not a huge priority at the current point in the project's timeline.

Also, toss in a quick description. I couldn't tell quickly from the post or site what Chatto _is_. I guessed a vibe coded LLM TUI because that's the new hotness. In a world of Yggdrasil and Immich and Czkawka, a very brief intro helps!
What's the rationale for the dual licensing? It looks like the Go backend is AGPL but the TypeScript frontend is Apache 2.0.

Why not keep it all AGPL?

Very cool. I don't usually get excited for new chat apps, but I like the idea of having one frontend for multiple servers instead of pushing hard on p2p or federation.

I do also still like irc, but haven't used it much in recent years because most of the people I talk to are using discord now.

I’m wondering about privacy tradeoffs. Looks like they’re similar to Discord where the chats won’t show up in web searches and you can’t read anything without joining. But if anyone can join, it’s not like Signal either and end-to-end encryption wouldn’t make sense.

(They do have end-to-end encryption for video.)

soooooo campfire then
Congrats for open sourcing it, looks interesting!

How does this compare to fluxer.gg though?

The part that I really liked about chatto is that it seems to be made very easily to self host which is something that I really appreciate actually.

I love Fluxer! Hampus is cool and what he's built is super impressive.

I would say the primary difference is that Chatto doesn't squarely aim for being a _Discord_ alternative. There are no plans for providing a Discord-compatible API (which I think Fluxer does.)

The other main difference is that Chatto is designed, on purpose, to serve individual communities from tiny deployments, instead of large mega-instances that power many communities. Chatto deliberately avoids content federation to remain compatible with business use cases, and also to stay simple enough so it can run from a single binary.

Couldn't help but smile because "chato" in portuguese means "boring", and this seems very easy to set up and use.

Here's to more boring software! :)

In Spanish chato mean small, like a small nose (una nariz chata). In some contexts it can mean "dude".
I absolutely love boring software. It's a very, very rare quality nowadays.
> Chatto aims to be the group chat application that you actually enjoy using.

So not like Discord or Slack?

> This is what it looks like:

Discord and Slack?

I mean, OK, it has EU hosting and that is good. But I see nothing obvious here that solves the noise and irritation of Discord and Slack.

I've been running Mattermost for a couple of years now and I'm content with it. It does feel a little bit clunky sometimes, but it's been stable and performant so I can't really complain. It can also feel a bit much sometimes. A bit too complex. A bit too feature-rich. But if I just ignore most of it, then it's good. I will say that Chatto looks nicer, appears to be simpler to setup and also has simpler licensing. Can it auto-update itself? That's something that's bad with Mattermost.
Does this federate with anything, like Matrix or XMPP? If it is locked into a single software, I fear nobody will ever switch to it (I have too many chat apps already!)
Looks great! How does it compare to Zulip? we self host zulip and are quite happy with it
zulip for one, is not encrypted at rest.
So encrypted at rest but no E2EE, did I read that right?
Yes, Chatto's core system does not use e2ee. This is by design; if there ever are e2ee features -- and chances are good they will, in some shape -- the encryption will be layered on top of that (encrypted message payloads and such.)
Looks great - is there any info on what server resources are actually required per feature or user count?
Still figuring out the numbers, so very hard to answer at the moment. Chatto is quite lightweight though; a fresh instance will run at tens of MB of RAM usage. RAM usage then scales with activity and CCU; on the Chatto HQ server, I'm currently seeing around 10 MB per additional connected user. I want this to be less, there's probably lots of room for optimization.

(You can scale Chatto horizontally across as many processes and servers as you need, so communities with tens of thousands of CCU should be perfectly feasible. But as you can imagine, there's precious little real-world proof for this yet :b)

Super happy to see someone take on slack. We just want a performant chat with simple features.

Slack integrations are overrated. Just give me webhooks.

Needs drop in voice rooms a la Discord or Slack's Huddle
It has audio and video call support in any room, so like huddle.