Phone System: Self-Hosted SMS & Call Gateway
📅 January 18, 2026 · ⏱️ 5 min read
A complete self-hosted solution for managing SMS messages and calls with real-time monitoring and SIM card storage
Having control over your own communication infrastructure is powerful. Our self-hosted Phone System provides a complete SMS & Call Gateway solution, giving you full control over your messaging and call management without relying on third-party services.
📱 What is the Phone System?
The Phone System is a self-hosted communication gateway that manages SMS messages and phone calls through a clean, modern web interface. It connects to physical SIM cards, allowing you to send and receive messages, manage conversations, and handle calls from anywhere with an internet connection.
🎯 Key Features
- 💬 SMS Management — Send, receive, and organize text messages with a clean conversation view
- 📞 Call Gateway — Handle incoming and outgoing calls through the web interface
- 💾 SIM Card Storage — Manage contacts and messages stored directly on your SIM cards
- 🟢 Real-Time Status — Live connection status and online/offline indicators
- 🔄 Conversation Threading — Messages organized by contact with timestamps and read status
- 📊 Message History — Full history of all conversations with search and filtering
🖥️ The Dashboard
The Phone System dashboard provides an intuitive interface for all your communication needs:
Conversations Panel
The left panel displays all your conversations in a familiar messaging layout. Each conversation shows the contact name (or phone number), the last message preview, and a timestamp. Unread messages are highlighted with a notification badge.
New Message Composer
The right panel features a clean message composer with:
- International phone number input with country code selector
- Character counter for SMS length (160 character limit)
- Quick send button with visual feedback
SMS & Calls Tabs
Easily switch between SMS and Calls views with the tab interface at the top. Each view is optimized for its specific function while maintaining a consistent user experience.
🔧 Technical Implementation
Tech Stack
- ⚙️ Backend — Node.js server handling modem communication and API endpoints
- 📡 Hardware — USB GSM modem for SIM card connectivity
- 🔌 Protocol — AT commands for modem control and message handling
- 🌐 Frontend — Modern JavaScript with real-time WebSocket updates
- 🔐 Security — Authentication system with session management
- 💾 Storage — SQLite database for message history and contact storage
How It Works
- Modem Connection: The system connects to a USB GSM modem with an active SIM card
- Message Handling: Incoming SMS messages are captured and stored in the database
- WebSocket Updates: Real-time notifications push new messages to the web interface
- Outgoing Messages: Messages composed in the UI are sent through the modem via AT commands
- Call Management: Incoming calls trigger notifications, outgoing calls are initiated through the modem
📋 Use Cases
The Phone System is perfect for:
- 🏠 Home Automation — Receive alerts and control smart home devices via SMS
- 🔔 Notifications — Send yourself alerts from servers, scripts, or IoT devices
- 🔐 2FA Receiving — Centralize two-factor authentication codes in one place
- 📱 Secondary Number — Manage a secondary phone number from your computer
🔮 Future Enhancements
Planned features for upcoming versions:
- Multi-SIM support for managing multiple numbers
- Scheduled message sending
- Contact management with groups
- MMS support for multimedia messages
- Call recording and voicemail
- API endpoints for external integrations
- Mobile app companion
💡 Why Self-Host Your Phone System?
Building your own phone gateway gives you complete control over your communications. There are no monthly fees for SMS APIs, no data sent to third parties, and full ownership of your message history. It’s a great project for anyone interested in telecommunications, home automation, or just wanting more control over their digital life.
The Phone System demonstrates how accessible modern communication technology has become. With a Raspberry Pi, a USB modem, and some code, you can build a fully functional SMS and call gateway that rivals commercial solutions.
— DankDev
Tags: Phone System · SMS Gateway · Self-Hosted · Raspberry Pi · Telecommunications · Node.js
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