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TerraCrypt Messenger

Messenger on a custom curve — End-to-end encrypted messenger across iOS, Android, Tauri desktop and a full self-hosted Go backend, with an admin dashboard and a complete observability stack. Group chats, voice, video and file transfer — all under cryptography that runs on the device. The first large system where the one-core-many-clients pattern proved itself, and the ancestor of the post-quantum rework in vChat.

Category
Flagship · iOS · Android · Desktop
Years
2022 → present
Status
live
Live
/terra ↗
TerraCrypt Messenger — Messenger on a custom curve
Screenshot 05 · TerraCrypt — clients on three platforms share the same C crypto layer.
01

What was built

  • Native iOS client in a modular SPM monorepo (Core*, Feature*) with its own crypto packages
  • Android client in Kotlin, data/domain/ui architecture, multi-module Gradle
  • Tauri desktop for Windows, macOS and Linux (~20 MB installer, no Chromium)
  • Go monorepo backend: API, signaling, push, payments, PostgreSQL + Redis migrations
  • CoTURN for NAT traversal and MinIO as S3-compatible encrypted media storage
  • Admin control plane (RBAC + audit trail) with real-time metrics
  • Observability: Grafana, Loki, Fluent-bit, Kibana, APM traces and Prometheus endpoints
02

Layers of the system

On-device cryptography

SwiftKotlinCJNI
  • Custom elliptic curve and own primitives, not just a call into someone's library
  • CoreCrypto / CoreCryptoDM / CoreCryptoGroup: primitives, DM and group encryption
  • Native C layer over JNI on Android — identical behaviour to iOS
  • Encrypted local database (SQLCipher) and a biometric vault

Clients

SwiftUICombineComposeTauri 2
  • iOS: SwiftUI + Combine, WebRTC group calls with own signalling
  • Android: Jetpack Compose, Hilt, Room, WorkManager for reliable background work
  • Desktop: Rust core + TypeScript/Vite, auto-update and code signing
  • A notification extension decrypts push messages before the OS shows them

Backend and observability

GoPostgreSQLRedisDockerGrafana
  • Go services in a Docker Compose stack, horizontally scalable
  • PostgreSQL as the main store with custom migrations, Redis for sessions and rate limiting
  • Apache and nginx reverse proxies with a vhost per service
  • Zero-downtime live updates on the production server
03

Technologies

Programming languagesSwift, Kotlin, Rust, TypeScript, Go, PHP, C
Frameworks & toolsSwiftUI, Combine, Jetpack Compose, Hilt, Room, Tauri 2, React, WebRTC
InfrastructurePostgreSQL, Redis, CoTURN, MinIO, Docker Compose, Grafana, Loki, Kibana
04

Facts

PlatformsiOS · Android · Desktop · Server
Statuslive
Years2022 → present
CategoryFlagship · iOS · Android · Desktop

TerraCrypt — clients on three platforms share the same C crypto layer.

All projects

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