backspace

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Backspace is a self-hosted, open-source Discord alternative: a Discord-style chat platform you run on your own hardware. Spaces, channels, roles, voice and video, screen sharing, direct messages, friends, file sharing, and message search. On top of that, server-to-server federation lets independent Backspace instances talk to each other while each stays under its own control.

It is free and open source under the GNU AGPL-3.0, and dual-licensed: a commercial license is available if the AGPL doesn’t fit your use. See License for the details.

Project status Backspace 1.x. Stable, self-hostable, and actively developed. The release badge above tracks the current version.

What makes Backspace different

Self-hosted chat usually forces a trade-off: gaming-grade voice and video, or a polished Discord-style experience, or federation between independent servers. Rarely all three, and rarely with the fine-grained media controls people expect.

Backspace does all three at once:

• Voice and video with a real control surface. This goes past a screen-share button. Choose resolution, frame rate, codec (VP9 or H.264), and bitrate; set independent 0-200% volume for every person and every screen-share; RNNoise noise suppression; a live connection inspector (bitrate, codec, ping, packet loss, jitter); and a per-tile badge showing each stream’s measured resolution and frame-rate. Screen sharing goes up to 4K/120fps within admin-set bounds.
• Federation, not a walled garden. Run your own instance and peer it with others for cross-instance friends, DMs, calls, and presence. Each server stays independently owned, and requests are HMAC-authenticated.
• A complete platform, not a demo. Role-based permissions with per-category and per-channel overrides, friends and group DMs, inline playable media, moderation with audit trails, search, a desktop app, and an installable mobile PWA, all in the warm, calm “Aether Drift” interface.

You own the server, the data, and the network it federates into.

Screenshots

Text channels. Markdown, replies, reactions, and live typing indicators.	Screen-share controls. Resolution, frame rate, codec, and bitrate, within admin-set bounds.
Spaces and discovery. Browse public, request-to-join, and joined spaces.	Direct messages. 1-on-1 and group DMs, including members on peer instances.
Friends and social. Find people across instances with mutual friends and spaces.	Federation admin. Manage peered instances, relay, and secret rotation.

Features

Communication

• Real-time text channels over WebSocket, with @mention autocomplete and mention highlighting
• Markdown formatting with syntax highlighting
• Message reactions, replies, editing, deletion, and per-message mark-as-unread
• Rich link embeds (YouTube, Vimeo, Spotify, and generic OpenGraph) with SSRF-protected scraping, plus GIF search (Klipy)
• Typing indicators, unread badges, and presence
• Direct messages: 1-on-1 and group DMs (up to 10 people), with voice/video calls (ring, accept, reject)

Voice, video, and screen sharing (via LiveKit):

• Screen sharing up to 4K/120fps: VP9 by default, optional H.264 (hardware acceleration depends on the browser, GPU, and driver), and a dynacast-managed VP8 simulcast fallback
• Per-stream quality controls: resolution, frame rate, codec, and bitrate, within admin-set bounds
• Independent 0-200% volume for every participant and every screen-share
• RNNoise noise suppression (on by default), plus echo-cancellation and auto-gain toggles and mic/speaker device selection
• Live connection inspector for per-participant bitrate, codec, ping, packet loss, and jitter, plus a per-tile badge showing each stream’s measured resolution and frame-rate
• Screen-share viewer detection (“who’s watching”) and auto-ducking that lowers stream audio when someone speaks
• Selective subscription: mute or stop watching any camera or stream to save bandwidth
• Push-to-talk and fully customizable keybinds (including mouse buttons), in the browser and the desktop app
• Picture-in-Picture for voice and video

Organization

• Spaces with channel categories
• Role-based permissions: bitwise RBAC with category- and channel-level overrides
• Customizable user sidebar layout, with personal color-coded folders that group whole spaces
• Space discovery (public, request-to-join, and private)
• Shareable invite codes

Social

• Friend requests and friendships
• User search and discovery
• Mutual friends and mutual spaces
• User profiles with banner, bio, and accent color
• Presence and rich activities (playing, listening, watching, streaming, custom)
• Manual status (Online, Idle, or Do Not Disturb) with a custom status message
• Privacy controls: toggle discoverability and activity-status sharing

Moderation

• Bans with reason and moderator attribution (who, why, and when)
• Voice restrictions (space-level mute/deafen, persisted)
• Member move and force-disconnect
• Join-request approval for gated spaces

Federation

• Multi-instance peering with HMAC-signed server-to-server requests
• Federated identity resolution (username@instance)
• Cross-instance DMs: messages, reactions, and membership relay
• Cross-instance friends and presence
• File replication with size validation
• Background workers for outbox delivery, file download, peer health, and cleanup

Platform

• File uploads with image thumbnails (via sharp), drag-and-drop and paste-to-upload, and in-app avatar/banner cropping
• Message search with from:, has:, before:, and after: filters, plus jump-to-message
• Admin panel: instance settings, user management, registration controls, storage management, and federation/peering, plus granular streaming controls (a per-resolution by per-frame-rate bitrate matrix, min/max caps, quality-slider step, and an optional user-set-bitrate mode)
• Automatic SQLite backups (pre-migration, scheduled, and manual) with restore tooling
• Electron desktop app (Windows, macOS, Linux) with global keybinds (push-to-talk, mute, deafen) and activity detection
• Native desktop notifications and unread badge counts
• Mobile-responsive web UI with a dedicated touch layout (bottom navigation, swipe gestures, full-screen views)
• Installable PWA: add it to your phone’s home screen to run it as a standalone app, with service-worker caching and an offline message queue (messages send once you reconnect)
• Account management: password change and account deletion with safeguards

Installation

The intended way to deploy Backspace is the interactive installer. It configures everything (.env, secrets, HTTPS, optional voice) and brings the stack up for you. It auto-detects your environment and picks one of three deployment modes. The default “All-in-One” (below) needs nothing but a host and a domain, but if ports 80/443 are already taken (an existing reverse proxy, a tunnel, another app) the installer steers you to the right mode instead of dead-ending. See Deployment modes for the full picture.

By default the installer pulls a prebuilt multi-architecture image from the GitHub Container Registry (linux/amd64 + linux/arm64), so weak or ARM boxes (a Raspberry Pi) skip the heavy local build. It falls back to building from source automatically if the image can’t be pulled.

Requirements

• A Linux host (VPS, VM, or home server) with Docker and Docker Compose.
• A domain name for your instance. In the default All-in-One mode it must point at the host’s public IP (Caddy obtains HTTPS certificates for it automatically); behind your own reverse proxy or a tunnel it points at that edge instead. See Deployment modes.
• The ability to open the firewall ports in step 2 (All-in-One), or a reverse proxy / tunnel already terminating HTTPS for you.

1. Run the installer

git clone https://github.com/TheZwiss/backspace.git
cd backspace
./install.sh

The installer walks you through everything interactively:

• asks for your domain,
• generates a secure JWT_SECRET,
• optionally enables voice/video (sets up the bundled LiveKit server),
• writes .env (and livekit.yaml if voice is enabled),
• starts all services with Docker and configures automatic HTTPS via Caddy.

2. Open the firewall ports

Open these on the host (and, if it’s behind a router, port-forward them to the host):

Port	Proto	When	Purpose
80	TCP	Always	HTTP. Caddy’s automatic-HTTPS (ACME) challenge + redirect to HTTPS
443	TCP	Always	HTTPS. Web app, REST API, WebSocket, and LiveKit signaling (proxied)
3478	UDP	If voice enabled	TURN. NAT traversal for WebRTC
7881	TCP	If voice enabled	WebRTC TCP fallback (clients that can’t use UDP)
50000–60000	UDP	If voice enabled	WebRTC media (voice / video / screen-share streams)

Without voice, you only need 80 and 443. The voice ports are required only when you enable LiveKit. LiveKit’s own signaling port (7880) stays internal. It’s reverse-proxied through Caddy on 443, so you do not forward it.

Do this together with DNS, ideally before (or right after) running the installer. Caddy gets your HTTPS certificate from Let’s Encrypt the first time the stack starts, which requires your domain to resolve to this host and ports 80/443 reachable from the internet. If they aren’t ready yet, that’s fine. Caddy keeps retrying, and HTTPS comes up automatically once DNS and the ports are in place.

3. Create your admin account

Open https://your-domain and register. The first account created becomes the instance admin. There is no default username or password.

If the page doesn’t load over HTTPS, it’s almost always DNS or ports 80/443 not being reachable from outside. Check docker compose logs caddy for certificate errors. (The installer’s health check confirms the app is up internally, not that the certificate was issued.)

Backups & restore

The app takes automatic SQLite snapshots (before every migration, on a schedule, and on demand via ./backup.sh). Restore from a snapshot with ./restore.sh. See docs/systems/deployment.md for the full backup/restore and image-pinning guide.

Manual setup (advanced, optional)

The installer above is the supported path. If you’d rather configure everything by hand, you can skip it and drive Docker Compose directly, but then DNS, .env, secrets, voice config, and the same firewall ports from step 2 are your responsibility:

git clone https://github.com/TheZwiss/backspace.git
cd backspace

cp .env.example .env
# Set DOMAIN, and generate a secret:
echo "JWT_SECRET=$(openssl rand -hex 32)" >> .env

docker compose up -d

The stack runs three services via Docker Compose:

Service	Role
backspace	The app (API + WebSocket + built web client) on internal port 3000
caddy	Reverse proxy with automatic HTTPS for your DOMAIN (ports 80/443)
livekit	Voice/video server; optional, enabled with COMPOSE_PROFILES=voice

Deployment modes

Homelabs differ. Backspace supports three deployment modes from one installer, which auto-detects which one fits and, in non-obvious cases, asks. The mode is recorded as DEPLOY_MODE in .env; you can also set it up front for a non-interactive install (DEPLOY_MODE=proxy ./install.sh).

Mode	When	HTTPS handled by	Voice
allinone (default)	Ports 80/443 are free and you have a domain	The bundled Caddy (automatic Let’s Encrypt)	Yes, with UDP media ports open
proxy	You already run a reverse proxy (nginx, Traefik, Caddy, Nginx Proxy Manager, SWAG…)	Your reverse proxy	Yes, if you also proxy /livekit and open the media ports
tunnel	You expose the box through a tunnel (Cloudflare Tunnel, Tailscale…)	The tunnel provider	No, WebRTC/UDP can’t traverse a tunnel

In proxy and tunnel mode the bundled Caddy is not started; instead the app is published on 127.0.0.1:APP_PORT (loopback only, never exposed directly) for your proxy or tunnel to forward to. This is driven by a small overlay, docker-compose.proxy.yml, which the installer wires in for you by setting COMPOSE_FILE=docker-compose.yml:docker-compose.proxy.yml in .env, so every later docker compose … command in the directory keeps working with no -f flags. The installer auto-picks a free APP_PORT (3000/8080 are often taken); override it with APP_PORT=….

The installer prints ready-to-paste config for your mode at the end. The canonical snippets are below.

Mode 2: behind your own reverse proxy

The app answers plain HTTP on 127.0.0.1:APP_PORT; your proxy terminates TLS and forwards to it. Every snippet already includes the three things people get wrong: WebSocket upgrade (chat and live events won’t work without it), X-Forwarded-* (the server runs with trustProxy and needs the real client scheme/IP), and a body-size limit matching MAX_UPLOAD_SIZE (default 100 MB).

Replace chat.example.com and 8080 with your domain and APP_PORT.

If your public port is not 443 (a home connection where the ISP blocks 80 and 443, say), put the port in DOMAIN itself: DOMAIN=chat.example.com:1443. That is the host clients type, and every URL the instance advertises is built from it. Make your proxy listen on that port and pass the Host header through unchanged; the snippets below already do ($http_host in nginx, since $host drops the port). Only proxy mode supports this: the bundled Caddy needs 80 and 443 for certificates, and a tunnel always serves on 443 at its edge. Federation with a port in DOMAIN is not supported yet.

nginx. The map goes in http { } once; the server block per site:

map $http_upgrade $connection_upgrade { default upgrade; '' close; }

server {
    listen 443 ssl;
    server_name chat.example.com;

    # ssl_certificate     /etc/letsencrypt/live/chat.example.com/fullchain.pem;
    # ssl_certificate_key /etc/letsencrypt/live/chat.example.com/privkey.pem;

    client_max_body_size 100m;        # match MAX_UPLOAD_SIZE

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_http_version 1.1;
        proxy_set_header Host              $http_host;   # not $host: it drops the port
        proxy_set_header X-Real-IP         $remote_addr;
        proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Host  $http_host;
        proxy_set_header Upgrade    $http_upgrade;        # WebSocket
        proxy_set_header Connection $connection_upgrade;  # WebSocket
        proxy_read_timeout 3600s;
        proxy_send_timeout 3600s;
    }

    # Voice only: forward LiveKit signaling (strips the /livekit prefix):
    # location /livekit/ {
    #     proxy_pass http://127.0.0.1:7880/;
    #     proxy_http_version 1.1;
    #     proxy_set_header Host       $http_host;
    #     proxy_set_header Upgrade    $http_upgrade;
    #     proxy_set_header Connection $connection_upgrade;
    # }
}

Caddy (if you run your own; it handles WebSocket and X-Forwarded-* itself):

chat.example.com {
    reverse_proxy 127.0.0.1:8080
    request_body { max_size 100MB }

    # Voice only:
    # handle_path /livekit/* { reverse_proxy 127.0.0.1:7880 }
    # handle           { reverse_proxy 127.0.0.1:8080 }
}

Traefik (file provider; Traefik handles WebSocket automatically):

http:
  routers:
    backspace:
      rule: "Host(`chat.example.com`)"
      entryPoints: [websecure]
      service: backspace
      tls: { certResolver: letsencrypt }
  services:
    backspace:
      loadBalancer:
        servers:
          - url: "http://127.0.0.1:8080"
  # Voice only: add a higher-priority router + stripPrefix middleware for
  # PathPrefix(`/livekit`) → http://127.0.0.1:7880.

GUI proxies (Nginx Proxy Manager, SWAG, etc.)

You can’t paste a config file into a point-and-click proxy, so set these fields by hand. In Nginx Proxy Manager, add a Proxy Host:

Field	Value
Domain Names	chat.example.com
Scheme	http
Forward Hostname / IP	127.0.0.1, but if NPM runs in Docker, 127.0.0.1 is NPM’s own container. Use the host’s LAN IP, or host.docker.internal with extra_hosts: ["host.docker.internal:host-gateway"] on the NPM container.
Forward Port	your APP_PORT (e.g. 8080)
Websockets Support	ON (required; chat/live events break without it)
Block Common Exploits	fine to leave on
SSL tab	request a Let’s Encrypt cert and enable Force SSL
Advanced tab	add client_max_body_size 100m; (match MAX_UPLOAD_SIZE)

The same three ideas apply to any GUI proxy: forward to the app’s host+port, enable WebSocket support, and raise the request-body limit.

Mode 3: behind a tunnel (Cloudflare, Tailscale)

Same loopback publish as Mode 2, but the tunnel daemon on the host reaches 127.0.0.1:APP_PORT and no inbound ports are opened at all. For Cloudflare Tunnel (cloudflared):

# ~/.cloudflared/config.yml
tunnel: <YOUR-TUNNEL-ID>
credentials-file: /root/.cloudflared/<YOUR-TUNNEL-ID>.json

ingress:
  - hostname: chat.example.com
    service: http://127.0.0.1:8080
  - service: http_status:404

cloudflared tunnel route dns <YOUR-TUNNEL-ID> chat.example.com

Two tunnel-specific caveats, both handled by the installer:

• Upload cap. Cloudflare (free/pro) hard-caps request bodies at 100 MB, so the 100 MB default would let large uploads fail at the edge. In tunnel mode the installer sets MAX_UPLOAD_SIZE=94371840 (90 MB) with headroom. Don’t raise it back above ~100 MB behind Cloudflare.
• No voice. Voice/video is WebRTC over UDP, which a tunnel can’t carry, so it’s disabled in tunnel mode. If you need voice, use Mode 2 (reverse proxy) with the media ports opened, or All-in-One.

Voice per mode

Voice/video (LiveKit) needs its UDP media ports reachable from clients. These carry the actual audio/video and never pass through your HTTP proxy or tunnel:

Port	Proto	Purpose
3478	UDP	TURN. WebRTC NAT traversal
7881	TCP	WebRTC TCP fallback
50000–60000	UDP	WebRTC media (voice / video / screen-share)

• All-in-One. Voice works once those ports are open/forwarded. LiveKit signaling is proxied through Caddy on 443 (/livekit); port 7880 stays internal, never forwarded.
• Reverse proxy. You must also route /livekit to 127.0.0.1:7880 (see the commented lines in the snippets) and open the media ports above.
• Tunnel. Voice does not work (UDP can’t traverse the tunnel). This is a known, unavoidable limitation, not a misconfiguration.

Updating a running instance

From the install directory:

./update.sh          # update, with one confirmation prompt
./update.sh --check  # see whether an update exists, changing nothing

update.sh takes a database snapshot, refreshes the checkout where that is possible, fetches the new image (pulling or rebuilding to match how you installed), and restarts only the backspace container. It then waits for the healthcheck and verifies the running version actually changed. If either fails, it puts back the image you were on and tells you what happened. A no-op update is detected and skips the restart entirely, so nobody gets dropped from a voice call for nothing.

Signed-in admins can see the running version and whether an update exists under Instance Settings, Updates, which also shows the exact command for their install.

If you do not have update.sh yet (it ships from 1.0.5), take a snapshot with ./backup.sh, then:

git pull                              # refresh compose files / install.sh / docs

# Prebuilt-image installs (the default):
docker compose pull backspace && docker compose up -d backspace

# From-source installs (a fork, or BACKSPACE_BUILD=true):
docker compose up -d --build backspace

Because COMPOSE_FILE lives in .env, these commands automatically use the right compose files in every mode, with no -f flags to remember. A redeploy briefly restarts the backspace container (clients reconnect automatically).

Name the backspace service and do not pass --remove-orphans. If you run other containers in the same compose project, Compose will suggest that flag, and following it deletes them.

Development

Requirements: Node.js 22.12 or newer and pnpm 10. The .nvmrc file selects Node 24, which is the active LTS and the version the Docker image runs. CI runs the suite on both Node 22 and Node 24. Node 20 reached end of life in April 2026 and is no longer supported: the native SQLite driver needs Node 22. Newer majors generally work but are not part of the test matrix.

pnpm install
cp .env.example .env          # set JWT_SECRET (openssl rand -hex 32)
pnpm dev                       # API server on :3005, Vite dev server on :5173

On Windows PowerShell, confirm Node 22 or newer and use the native copy command:

node --version
pnpm install
Copy-Item .env.example .env
node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"

Paste the generated value after JWT_SECRET= in .env, then start both development servers with pnpm dev. Use node --version to confirm the active version if pnpm reports an engine warning. This covers the server and web dev servers; building the Electron desktop app still expects a POSIX shell (macOS or Linux).

Server/web only? pnpm install also builds the desktop app’s native keyboard-hook module (uiohook-napi), which needs a C++ toolchain (make, g++, python3). If those are missing it now warns and continues, and the server and web client don’t need it. Install a build toolchain (Debian/Ubuntu: sudo apt install build-essential python3) only if you’re building the desktop app. And to self-host, use the Docker installer above; it never touches the desktop package.

Run the halves separately if you prefer:

pnpm dev:server   # API + WebSocket on :3005
pnpm dev:web      # Vite dev server on :5173

Build everything for production (shared types → server → web):

pnpm build

In production the server serves the built web client directly.

Configuration

All configuration is via environment variables (see .env.example). The most important:

Variable	Required	Default	Description
DOMAIN	yes	none	Public domain name of your instance
JWT_SECRET	yes	none	Auth signing secret, min 32 chars (openssl rand -hex 32)
DEPLOY_MODE	no	allinone	allinone | proxy | tunnel, see Deployment modes
APP_PORT	no	auto	proxy/tunnel only: host loopback port the app is published on
PORT	no	3000	App listen port (behind Caddy in Docker)
HOST	no	0.0.0.0	Bind address
REGISTRATION_OPEN	no	true	Set false to close signups after setup
MAX_UPLOAD_SIZE	no	104857600	Max upload size in bytes (100 MB; 90 MB in tunnel mode)
BACKSPACE_IMAGE / BACKSPACE_IMAGE_TAG	no	ghcr.io/thezwiss/backspace / latest	Prebuilt image to pull; pin a tag or point at your fork’s registry
LIVEKIT_URL / LIVEKIT_API_KEY / LIVEKIT_API_SECRET	no	none	Enable voice/video
COMPOSE_PROFILES	no	none	Set to voice to start the bundled LiveKit service
FEDERATION_ALLOW_PRIVATE_PEERS	no	false	Set true only on a LAN-only deployment, so instances on private addresses can still peer when a user adds a handle. Admin-driven peering with a private peer works either way.
TELEMETRY	no	none	on or off: answer the opt-in usage hello at install time instead of in the app. See Privacy.

Voice & Video

Voice, video, and screen sharing require a LiveKit server. The Docker Compose file bundles one. Enable it by setting these in .env:

COMPOSE_PROFILES=voice
LIVEKIT_URL=wss://your-domain
LIVEKIT_API_KEY=your-api-key
LIVEKIT_API_SECRET=your-api-secret

Enabling voice also requires opening the WebRTC ports (3478/UDP, 7881/TCP, 50000–60000/UDP). See Open the firewall ports.

Without LiveKit configured, everything else works fully (text, federation, DMs, uploads, search); only voice/video channels won’t connect.

Federation

Backspace instances can peer with each other so users on different servers can become friends, DM, and call across instances, while each instance stays independently owned and operated. Peering is mutual and authenticated with HMAC-signed requests; identities are addressed as username@instance. Manage peers from the Connections panel in settings. The protocol is documented in docs/systems/federation.md and docs/systems/client-federation.md.

Desktop App

The Electron desktop app wraps the web client and adds a system tray, native notifications, global keybinds, and activity detection.

Download

Grab the installer for your platform from the latest release:

Platform	File	Notes
Windows	Backspace-<version>-win-x64.exe / -win-arm64.exe	Pick x64 unless you know the machine is ARM; the x64 build also runs on Windows on ARM. SmartScreen may warn on first run; choose “More info” → “Run anyway”. Auto-updates.
Linux	Backspace-<version>-linux-x86_64.AppImage / -linux-arm64.AppImage, or -linux-amd64.deb / -linux-arm64.deb	AppImage auto-updates; .deb installs update via new releases.
macOS	Backspace-<version>-mac-arm64.dmg (Apple Silicon) / -mac-x64.dmg (Intel)	Builds are ad-hoc signed but not notarized, so Gatekeeper blocks the first launch. Open it once, dismiss the warning, then go to System Settings → Privacy & Security and click Open Anyway next to the Backspace message. On macOS 14 and earlier, right-click the app → Open → Open works instead. Auto-update is not available on macOS yet, so check the releases page for new versions.

Every release also carries .blockmap and latest*.yml files. The auto-updater reads those; they are not downloads.

On first launch the app asks for your instance URL. Enter the address of the Backspace server you use (e.g. https://chat.example.com).

Linux users can also build and install the Flatpak manifest locally. See flatpak/README.md for the commands and sandbox details.

Building from source

cd packages/desktop
pnpm build:ts    # compile TypeScript
pnpm dev         # run in development
pnpm build       # package for distribution

Cross-platform builds are produced for Windows, macOS, and Linux. See docs/systems/desktop.md.

Mobile

Backspace works on mobile today. Just open your instance in a phone browser. The UI has a dedicated touch layout (bottom navigation, swipe gestures, and full-screen views), and because it ships as an installable PWA you can use your browser’s Add to Home Screen to install it as a standalone app: its own icon, no browser chrome, and an offline message queue that flushes when you reconnect.

Native iOS and Android app-store apps are planned, once the project gains traction and the funding for the developer-program licenses is secured. Until then, the installable PWA is the supported way to run Backspace on a phone.

Architecture

Backspace is a TypeScript monorepo managed with pnpm workspaces.

packages/
  shared/   - Shared types, permission bits, constants
  server/   - Fastify API + WebSocket server, Drizzle/SQLite, federation
  web/      - React 18 SPA (Vite, Tailwind, Zustand)
  desktop/  - Electron wrapper

Layer	Technology
Server	Node.js 22+, Fastify 4, TypeScript (strict)
Database	SQLite (better-sqlite3) + Drizzle ORM
Auth	JWT + bcrypt
Frontend	React 18, Vite 8, Tailwind CSS 3, Zustand 5
Voice/Video	LiveKit
Media	sharp (thumbnails), Cheerio (embeds)
Desktop	Electron 43
Deployment	Docker Compose + Caddy (auto-HTTPS)

Every subsystem has a dedicated specification under docs/systems/: database schema, REST API, WebSocket protocol, federation, permissions, voice, the design system, and more. These are the reference for how Backspace works; start there if you want to understand or extend a subsystem.

FAQ

Is Backspace a self-hosted Discord alternative? Yes. It gives you a Discord-style experience (spaces, channels, roles, voice, video, screen sharing, DMs, friends) that you run entirely on your own server, so you own the data and set the rules.

How is it different from Revolt, Spacebar, Matrix, or Mumble? See the full comparison, including where each of those is the better choice. In short: Backspace pairs a Discord-style client with a serious voice and screen-share control surface and optional server-to-server federation.

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; text, federation, DMs, and everything else run fully without them.

Can I self-host it on a Raspberry Pi? Yes. The installer pulls a prebuilt multi-architecture image (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. A separate commercial license is available for cases the AGPL does not fit. Every released version stays available under the AGPL.

Does it work on mobile? Yes, as an installable PWA with a dedicated touch layout. Native iOS and Android apps are planned.

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.

Contributing

Contributions are welcome. Please read CONTRIBUTING.md first. Backspace is a single-owner project, so all contributors sign a Contributor License Agreement, a one-time comment on your pull request, handled automatically by a bot. You keep the copyright to your contribution and grant the maintainer (Jannis Braun) an exclusive license to it, which is what lets Backspace be offered under both the AGPL and a commercial license. You also receive a perpetual license to reuse the specific code you wrote in your own other projects.

Privacy

Backspace tracks nobody. There is no analytics, no crash reporting, and nothing phones home on its own. The one exception is opt-in: an admin can let their instance send me a once-a-day hello with rounded counts (people, messages, the version, whether voice and federation are on) and the country the request came from. No names, no message content, no addresses of any kind. It stays off until an admin says yes, in Instance settings or with TELEMETRY=on at install time, and can be turned off again at any time. Everything that comes back is published as open data on the insights page. What is sent, how it is stored and for how long is documented in docs/systems/telemetry.md.

Security

If you discover a security vulnerability, please do not open a public issue. Report it privately via a GitHub security advisory on this repository. See SECURITY.md. We’ll work with you on a fix and coordinated disclosure.

Security and supply chain

Every change is scanned automatically before and after it lands. Results are published to this repository’s Security tab.

What	Tool	When
Static analysis of the TypeScript	CodeQL	every pull request, every push to main, weekly
Known vulnerabilities in dependencies	OSV-Scanner	every pull request, every push to main, weekly
Secrets, across the full git history	gitleaks	every pull request, every push to main, weekly
Infrastructure and container config	Trivy	every pull request, every push to main, weekly
Dependency licenses	Trivy	every pull request, every push to main, weekly
The published container image	Trivy	on every image publish
Repository security posture	OpenSSF Scorecard	every push to main, weekly
A running instance	OWASP ZAP baseline	every push to main, weekly
Dependency and base image updates	Dependabot	weekly

Supporting practice: every GitHub Action is pinned to a full commit SHA rather than a tag, every job runs on a hardened runner with egress auditing, and workflow permissions are granted per job instead of repository-wide. Published images carry a software bill of materials and build provenance.

Findings are triaged rather than accumulated. Anything dismissed carries a written reason, recorded in docs/systems/security-scanning.md, which also documents the scan policy, the known gaps, and the deployment-time settings a self-hoster should check.

License

Backspace is free and open source software, licensed under the GNU Affero General Public License v3.0 (AGPL-3.0-only).

In plain terms:

• Yes: self-host, run, study, and modify it, including commercially and inside a business.
• Yes: redistribute it and your changes under the same AGPL-3.0 license.
• Note: if you run a modified version as a network service, you must offer your users its complete corresponding source (AGPL § 13). Backspace makes this easy: set BACKSPACE_SOURCE_URL to your fork so the in-app “Source code” link points at what you actually run.
• Note: preserve the copyright and license notices.

Commercial license. If the AGPL doesn’t fit (embedding Backspace in a closed-source product, offering it as a managed service without publishing your modifications, or an organization that can’t use AGPL software), a separate commercial license is available on request. See LICENSE-COMMERCIAL.md.

Our open-source commitment. Every released version of Backspace is, and will remain, available under the AGPL-3.0. The Contributor License Agreement exists to enable a commercial license and optional enterprise add-ons, not to take the open-source edition private. If this project is ever abandoned, or the open-source edition is relicensed under non-free terms, the community stays free to fork the last AGPL release.

Copyright © 2026 Jannis Braun. Contributions are made under the Contributor License Agreement: you keep your copyright and grant the maintainer an exclusive license, which is what lets Backspace be offered under both the AGPL and a commercial license.

“Backspace”, the Backspace logo, and app icons are trademarks of Jannis Braun and are not licensed under either the AGPL or the commercial license. Bundled third-party components retain their own licenses; see NOTICE.

Acknowledgements

Built on the shoulders of Fastify, Drizzle ORM, React, LiveKit, Tailwind CSS, Electron, and the broader open-source ecosystem. The interface uses DM Sans and Inter (SIL Open Font License 1.1).