Challenge: Messaging App

Overview

Your challenge is to build a real-time messaging application using Holochain’s scaffolding tools and signals functionality.

Key Learning Goals

Through this challenge, you’ll gain practical experience with:

  • Using Holochain’s scaffolding tools for rapid development
  • Implementing real-time communication with signals
  • Building interactive features in a distributed application
  • Creating secure messaging between agents

Getting Started

The starter code and detailed instructions are available in the challenge repository:

Messaging App Challenge Repository

You can view the difference between the starter code and the sample solution here.

Quick Setup

# Clone the repository
git clone https://github.com/CodeWithJV/holochain-challenge-4
cd holochain-challenge-4

# Enter the nix shell for development
nix develop

Tips

  • The hc scaffold command can save you lots of time on boilerplate code
  • Signal handlers must be registered during initialization
  • Test signals with multiple agent scenarios to ensure they work properly
  • For typing indicators, consider using a debounce function to avoid sending too many signals
  • Remember that signals are not guaranteed to be delivered, so design your application accordingly
  • Use the scaffolding tool’s generated code as a reference, but customize it to fit your specific needs

Requirements

  1. Use Scaffolding Tools

    • Use the hc scaffold command to generate entry types and CRUD operations
    • Create a message entry type with scaffolding
    • Generate appropriate validation callbacks

  2. Implement Direct Messaging

    • Create functionality for sending messages between agents
    • Implement conversation threads
    • Add support for retrieving message history

  3. Real-time Notifications with Signals

    • Send signals when new messages are created
    • Implement handlers to receive signals from other agents
    • Create real-time notifications for message delivery

  4. Enhanced Features

    • Add typing indicators using signals
    • Implement read receipts
    • Create user presence indicators (online/offline status)

  5. Security and Validation

    • Ensure message privacy between participants
    • Validate message content appropriately
    • Implement proper error handling for signals