open source, AGPL-3.0 · your hardware, your rules

# Group chat that lives on your own hardware.

Backspace is a self-hosted, open-source Discord alternative: spaces, roles, voice and video, screen sharing up to 4K at 120fps, and federation between servers that stay independently owned.

Get it on GitHub How it compares

one interactive installer · automatic HTTPS · runs on a Raspberry Pi

a k c +
attic lab
text
# general
# selfhosted
# 3d-printing
voice
lounge
mara
felix
jonas
Voice Connected
lounge · 34ms
mara
@mara
#general the server lives in the closet now
mara 21:04

moved us off discord last night. the whole thing runs off the pi in my closet now

jonas 21:04

how painful was the setup

mara 21:05

one installer. caddy grabbed the certs itself, first account became admin. that was it

felix 21:05

come to lounge, I'll stream the factorio base

jonas 21:06

ok this share is stupidly sharp. what is this, 1440p?

felix 21:06

4k. open the connection inspector if you don't believe me

mara is typing
Message #general
owner · 1
mara
online · 2
felix
jonas
voice-and-screen-share

## A control surface, not a mute button.

Most chat apps give you one volume slider and a codec you never see. Backspace hands you the signal path. When a stream stutters, the connection inspector shows you what is happening on the wire, so you fix it instead of guessing at it.

codec
  VP9 or hardware H.264, chosen per stream
resolution
  up to 4K at 120fps, inside bounds the admin sets
bitrate
  set it yourself, reset to auto anytime
volume
  0 to 200%, per person and per screen share
noise
  RNNoise suppression scrubs the keyboard clatter
inspector
  live bitrate, codec, ping, packet loss, jitter

voice and video run on LiveKit and are optional. everything else works without them.

real screenshots: a nine-person call, and the per-stream settings panel.

federation

## Independent servers, shared conversation.

Peer two Backspace instances and their users can be friends, message, and call each other, while every server stays the property of whoever runs it. Requests between servers are HMAC-signed, secrets rotate on a schedule you set, and a peer can be revoked at any time. There is no directory and no central anything: two admins agree, and their servers shake hands.

closet.mara.dev
owned and run by mara
HMAC-signed
rack.jonas.net
owned and run by jonas

Honest limits: this is Backspace-to-Backspace, not Matrix or ActivityPub, and it is young. If you want a mature, open federation standard today, Matrix is the better choice, and our comparison doc says exactly that.

from the admin panel: peers are health-checked, secrets rotate on schedule, and revocation is one click away.

the-rest-of-it

## The parts you'd expect, done properly.

roles-and-permissions bitwise roles, with overrides per category and per channel
group-dms direct messages and group calls for up to 10 people
moderation bans with reasons and audit trails, voice restrictions that persist
search full text across everything, with from: has: before: and after: filters
desktop-and-mobile an Electron desktop app, plus an installable PWA on phones
files-and-embeds uploads with thumbnails, link previews, GIF search

space discovery: public, request-to-join, and private spaces.

mara@closet:~
$
$
domain, ports, voice: the installer asks, you answer
HTTPS via Caddy: certificates arrive on their own
prebuilt image: amd64 and arm64, no local build
✓ up. the first account to register becomes admin.
install

## One installer, then it's yours.

The interactive installer walks you through Docker Compose, and Caddy handles HTTPS without being asked twice. There are no default credentials to forget about: the first account you register becomes the admin.

- runs on a Raspberry Pi: the prebuilt image covers amd64 and arm64
- your data is SQLite files on your own disk, with automatic backups
- AGPL-3.0, with a commercial dual license where the AGPL doesn't fit

before-you-star

## Read this before you star it.

Backspace is young, and you should pick tools with clear eyes. Three things it does not give you today:

- No Discord ecosystem. There is no bot marketplace and no army of integrations. You get the platform, not the crowd.
- Mobile is a PWA. It installs to your home screen and works well, but native iOS and Android apps are still on the roadmap.
- The federation is young. It peers Backspace with Backspace. For a mature open standard across many ecosystems, Matrix is the better pick.

how-it-compares

## An honest snapshot.

The full write-up, including where each of these is the better choice, lives in the comparison doc.

Capability | Backspace | Discord | Revolt | Matrix | Mumble
--- | --- | --- | --- | --- | ---
Self-hostable | Yes | No | Yes | Yes | Yes
Open source | AGPL-3.0 | No | Yes | Yes | Yes
Discord-style UX | Yes | Yes | Yes | Different | No
Video and screen share | Up to 4K/120fps | Yes | Limited | Yes | No
Per-stream media controls | Yes | No | No | Partial | Audio only
Federation | Between instances | No | No | Yes, open standard | No

questions

## Questions people actually ask.

Is Backspace a self-hosted Discord alternative?

Yes. It gives you a Discord-style experience with spaces, channels, roles, voice, video, screen sharing, DMs, and friends, running entirely on your own server so you own the data and set the rules.

Does it have screen sharing and high-quality video?

Yes. Screen sharing goes up to 4K/120fps within admin-set bounds, with per-stream codec, bitrate, and resolution controls, RNNoise noise suppression, and a live connection inspector. Voice and video use LiveKit and are optional.

What does federation mean here?

Independent Backspace instances can peer with each other so users on different servers can be friends, DM, and call across instances, while each server stays independently owned. Requests between servers are HMAC-authenticated. It is Backspace-to-Backspace, not Matrix or ActivityPub.

Can I run it on a Raspberry Pi?

Yes. The installer pulls a prebuilt multi-architecture image for amd64 and arm64, so low-power and ARM boxes skip the heavy local build.

Is it really open source?

Yes, under the GNU AGPL-3.0, with a commercial dual-license option for cases the AGPL does not fit. Every released version stays available under the AGPL.

## The next place you hang out could be yours.

Clone it, run the installer, and you're the admin.

Get it on GitHub