Sojorn

A privacy-first social network with community safety features, end-to-end encrypted messaging, and neighborhood-based organizing.

Operator: MPLS LLC Status: Active Development — MVP near-complete

Licensing

This project uses a split licensing model:

Component	License	License File
Go API Engine (go-backend/)	BSL 1.1	Core platform engine
AI Gateway (ai-gateway/)	BSL 1.1	AI moderation pipeline
Flutter App (sojorn_app/)	Apache 2.0	Mobile/desktop client
Admin Panel (admin/)	AGPL-3.0	Administration interface
Website (website/)	AGPL-3.0	Public website

The BSL-licensed components (API engine and AI gateway) convert to Apache License 2.0 four years after each release. All source code is publicly available for audit and transparency.

Architecture

sojorn/
├── go-backend/        # Go API server (Gin + pgx v5 + PostgreSQL)
├── sojorn_app/        # Flutter mobile/web app (Riverpod)
├── admin/             # Next.js admin panel
├── website/           # sojorn.net (Astro SSR)
├── mpls-website/      # mp.ls (Astro SSR)
└── sojorn_docs/       # Internal docs and deployment notes

Go Backend

Framework: Gin + pgx v5 + PostgreSQL + PostGIS Port: 8080 (behind nginx at api.sojorn.net)

Key features:

• JWT auth with 15-minute access tokens + refresh tokens
• ALTCHA bot protection (proof-of-work, no tracking)
• Feed algorithm: 5-factor scoring, cooling period, diversity injection, impression recording
• Content moderation: Local AI (Ollama) + SightEngine text/image analysis, Three Poisons scoring
• E2EE messaging (Signal protocol key management)
• Community Safety Beacons with neutral-language filtering and coordinate fuzzing (~1.1km precision)
• Neighborhood boards with location-based discovery
• Groups and encrypted Capsules (E2EE group messaging)
• Cloudflare R2 media storage with signed URLs
• Push notifications via FCM
• Repost/boost system with amplification analytics
• Trust system (harmony score) with rate limiting
• Profile widget system with layout persistence

cd go-backend
go build -o bin/api ./cmd/api/...

Flutter App

State management: Riverpod Video: ffmpeg_kit_flutter_new (mobile), stub for web Platforms: Android, iOS, Web

Key features:

• Full post creation with rich text, images, video, audio overlays
• Quips (short-form video) with comment chains
• E2EE direct messaging (Signal protocol)
• Community Safety Beacons and neighborhood boards
• Group navigation, group feed, encrypted Capsules
• Signed media URL resolution via Go backend
• Profile privacy controls and NSFW blur toggles

cd sojorn_app
flutter pub get
flutter run

Admin Panel

Framework: Next.js 14 (App Router) + TailwindCSS Port: 3001

Includes: dashboard, user/post management, moderation queue, AI moderation config, appeals, reports, algorithm tuning, categories, neighborhoods, official accounts, groups/capsules, quip repair, storage browser, system health, reserved usernames, safe domains, email templates, audit log, AI audit log, waitlist, content tools.

cd admin
npm install && npm run dev

Websites

sojorn.net (website/)

Astro SSR site with privacy policy, terms of service, advertising policy, account deletion/data clearing forms (SendPulse integration). Runs via PM2 on port 4323.

mp.ls (mpls-website/)

MPLS LLC company site. Astro SSR with newsletter signup, project portal. Runs via PM2 on port 4322.

# Build either site
cd website && npm run build      # sojorn.net
cd mpls-website && npm run build  # mp.ls

Server Deployment

Server: Hetzner VPS at 116.202.231.103 OS: Ubuntu Reverse proxy: Nginx with Let's Encrypt SSL Process manager: PM2 (websites), systemd (Go API) Backups: Borgmatic (every 6h) + rclone sync to Cloudflare R2 (14-day retention)

# Full deploy from server
cd /opt/sojorn
git pull internal main

# Go backend
cd go-backend && go build -o bin/api ./cmd/api/...
cp bin/api ../bin/sojorn-api.new && mv ../bin/sojorn-api.new ../bin/sojorn-api
sudo systemctl restart sojorn-api.service

# sojorn.net
cd ../website && npm run build && pm2 restart sojorn-site

# mp.ls
cd ../mpls-website && npm run build && pm2 restart mp.ls

Database

Engine: PostgreSQL 16 with PostGIS Tables: 104 (as of Feb 2026) Migrations: go-backend/migrations/ (gitignored, force-add with git add -f)

# Run a migration
psql "$DATABASE_URL" -f go-backend/migrations/MIGRATION_FILE.sql

Git Remotes

Remote	URL	Purpose
internal	https://git.mp.ls/patrick/sojorn.git	Primary (Forgejo)
public	https://gitlab.com/patrickbritton3/sojorn.git	Public mirror

Data Privacy

• E2EE messages: server stores only ciphertext
• Board entry coordinates: fuzzed to ~1.1km before storage
• Beacon text: neutral-language filter applied automatically
• Expired tokens: purged daily via cron
• Moderation content snippets: auto-deleted after 14 days
• Cloud backups: 14-day rolling retention
• No third-party analytics, no cross-site tracking, no third-party ad SDKs
• Hard deletes with ON DELETE CASCADE on all user data
• Age requirement: 18+

Environment Variables

See go-backend/.env.example, website/.env.example, and mpls-website/.env.example for required configuration.