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Semaphore Chat

Self-hosted voice and text chat.

Semaphore Chat is an open-source communication platform that gives you full control over your data. Built with a modern stack — NestJS, React, PostgreSQL, and LiveKit — it provides real-time messaging, voice and video calls, and community management out of the box.

Features

  • Real-time messaging — WebSocket-powered text channels with mentions, reactions, threads, file attachments, and read receipts
  • Voice & video calls — Powered by LiveKit with screen sharing and system audio capture on the desktop app. Voice connections persist across page navigation
  • Replay capture — Continuously buffers screen share sessions so you can retroactively clip the last 1-10 minutes with a visual trim timeline. Share clips to channels, DMs, or save them to a personal clip library with storage quotas. See Replay Buffer Architecture
  • Desktop app — Electron client for Windows and Linux with a custom screen source picker showing live thumbnails, configurable resolution and frame rate, system tray integration, and auto-updates
  • Communities — Create servers with text and voice channels, private channels, direct messages, and group DMs with file attachments
  • Role-based access control — Granular permissions at the instance and community level, with community bans, timeouts, and moderation logs
  • Mobile-friendly — Responsive design with swipe navigation, mobile-optimized layouts, PWA support with push notifications
  • Self-hosted — Run on your own infrastructure with Docker Compose or Kubernetes. Your data stays yours

  • Installation

    Get Semaphore Chat running with Docker Compose — from first launch to production.

  • Configuration

    Environment variables reference for backend and frontend.

  • Kubernetes

    Deploy Semaphore Chat to a Kubernetes cluster with the official Helm chart.

  • Desktop App

    Download the Electron desktop client for Windows and Linux.

  • Contributing

    Help improve Semaphore Chat — bug reports, features, and code contributions.

Tech stack

Layer Technology
Backend NestJS (TypeScript)
Frontend React 19 + Vite + Material UI
Database PostgreSQL with Prisma ORM
Real-time Socket.IO with Redis adapter
Voice/Video LiveKit
State TanStack Query v5
Auth JWT with Passport.js
Desktop Electron

License

Semaphore Chat is dual-licensed under the AGPLv3 and a commercial license. Free for everyone — including commercial use — as long as you comply with AGPL terms. A commercial license is available for proprietary deployments.

Contact: licensing {at} semaphorechat [dot] app