Messaging toolkit powering the most
exciting communication experiences
Simple. Powerful. Feature rich.

Rich Messaging Features

  • Many different chats such as direct, group, channels
  • Any message type
  • Message storage
  • Offline message support

Multiplatform SDKs

  • Android, iOS, Web
  • Server to server Rest API
  • Open source

Powerful Platform

  • Secure, reliable and scalable
  • Lightweight messaging protocol
  • Grow platform and pricing with your needs


Rich Messaging

  • Various chat types
  • Direct chats (1:1)
  • Private group chats (one to many, invite only)
  • Public chat rooms (free to join)
  • Topic based chats with #Channels
  • Chat search and visibility management (private, public)
  • Chat member access rules (invite only, free to join, closed)
  • Chat member role and permission management (admin, member, moderator)
  • Custom properties for chat type individualisation
  • Member presence events (online, offline)
  • Unlimited message history
  • Message querying
  • Unread message count tracking
  • Synchronise chats between devices (real time)


  • Default message types with text, image, voice, video and location
  • Custom message types without limitations
  • Fire and Forget message delivery. Only received by online users.
  • Retained / Persisted message delivery. Message storage while offline, delivered when online.
  • Offline message storage and delivery on reconnect (push messages on connect)
  • Push notification forwarding (GCM, APN) to notify offline members
  • Message status indicators: Received, read
  • User typing / chat interaction indicator
  • Synchronise messages between devices (real time)


  • Fullstack solution: Messaging protocol, backend and infrastructure – designed, implemented and managed by MDK
  • Lightweight, reliable and secure messaging protocol based on MQTT
    JSON payload
  • Made for mobile: Response times, throughput and low battery consumption are key design criteria
  • Seamless integration with any existing user system
  • No user data required other than a user ident
  • Server-to-server Rest API to integrate MDK into existing workflows
  • Client-to-server Rest API for secure client-to-server communication
  • External service integration via webhooks to build complex or automated communication services

Made by developers for developers

  • Open source SDKs
  • All SDKs follow the same patterns and principles
  • Focus on complete documentation and developer friendly interfaces
  • Example applications for any supported platforms
  • Full working open source instant messaging app for Android, IOS and Web
    • Get started quickly
    • Prototyping
    • White label app
  • E-mail and chat support to connect immediately with MDK developers




  • Users (monthly)1,000
  • Support - basicBasic
  • SLA - StandardN/A
  • Platform APIN/A



  • Users (monthly)2,500
  • Support - basicEnhanced
  • SLA - StandardEnhanced
  • Platform APIYes



  • Users (monthly)10,000
  • Support - basicEnhanced
  • SLA - StandardEnhanced
  • Platform APIYes



  • Users (monthly)Unlimited
  • Support - basicEnterprise
  • SLA - StandardCustom
  • Platform APIYes


What customers say about MDK

“When at first I tried MDK, I thought it was exactly what we needed for Hello: a super enhanced system for real-time chat, with low battery consumption and unique features. Keep up the good work!”

Marco Fabbri

MDK Labs GmbH offices:

HQ German Office: Friedrichstraße 123 10117 Berlin, Germany, Telephone: +49 30 318 78 722

US Office: 101 West Broadway, Suite 1120, 92101 San Diego, California, USA, Telephone: +1 858 777 0055

Russian Office: Sheremetyevskaya 6 bld. 1 129594 Moscow, Russia, Telephone: +7 495 800 7000