Mosaic3

Mosaic is a decentralized marketplace and orchestration platform for AI agents that empowers both creators and users through blockchain-based ownership, access control, and seamless multi-agent workflows.

It’s built for a future where specialized AI agents become as common as mobile apps—and as easy to access. With Mosaic, AI creators can monetize their work directly by publishing agents as services, while users can browse, test, and pay for AI-powered solutions with precision, flexibility, and transparency.

How We Built Mosaic — The Nitty-Gritty

Core Technologies & Architecture

1. Frontend

We built the user interface using React 18 with functional components and hooks, combined with Vite for ultra-fast development and optimized production builds. Styling relies on Tailwind CSS for rapid UI development, complemented by Shadcn/ui components for accessibility and design consistency. The frontend handles the marketplace, agent discovery, chat interface, and the no-code orchestration workflow builder with smooth real-time interaction via WebSockets.

1. Backend

Our backend is a Node.js + Express REST API serving all platform data and business logic. It handles user management, agent metadata, transaction coordination, and orchestrates calls between AI services and blockchain interactions. We configured CORS carefully for security and structured the API to support scalable multi-tenant usage.

1. Blockchain Layer

We integrated with Hedera Hashgraph for smart contract deployment and transaction processing. Hedera provides:

Ultra-fast transactions (3–5 seconds)

Very low fees (< $0.01 per tx), enabling micro-payments

Enterprise-grade security and scalability

We wrote Solidity smart contracts using Hardhat for compiling, testing, and deploying contracts that govern NFT-based access tokens, revenue sharing, and agent ownership. The blockchain layer ensures that access rights are verifiable, time-limited, and that creators maintain ownership and get paid automatically.

1. Decentralized Storage

To avoid central points of failure, all agent metadata, conversation histories, and user data blobs are stored on Walrus, a decentralized storage network compatible with IPFS principles. This means data persists even if individual nodes go offline and ensures privacy via encryption.

1. AI Integration & Orchestration Engine

We use OpenAI’s API as the backbone for natural language understanding and generation, powering individual AI agents. On top, we built a custom multi-agent orchestration system that:

Routes user requests to appropriate specialized agents based on capabilities and reputation

Maintains context across agents to enable seamless conversations

Supports parallel task execution and dynamic rerouting in case of failures

The orchestration engine is implemented in the backend, exposing APIs that the frontend workflow builder consumes.

Partner Technologies & Benefits

Privy: We leveraged Privy for user authentication and Web3 wallet management. This allowed us to provide smooth social login (Google, Twitter, Discord) while abstracting blockchain wallet complexities away from end users. This drastically improved onboarding and user experience.

Hedera: Its fast, inexpensive transactions are perfect for micro-payment economics fundamental to Mosaic’s business model, something that typical blockchains can’t economically support at scale.

Walrus: Enabled us to keep data decentralized without sacrificing availability, enhancing platform trust and resilience.

Notable Hacks & Engineering Highlights

Time-Limited NFT Access Tokens:

We engineered smart contracts that automatically burn NFTs after their expiration time, creating a “rental” model for AI services on-chain. This required clever use of contract timers and event-driven logic to maintain decentralization while automating expiry without external intervention.

Seamless Multi-Agent Context Sharing:

Maintaining conversation context across different AI agents in real-time is challenging. We designed a lightweight, encrypted context-passing mechanism stored temporarily on decentralized storage and cached by the backend to ensure consistent user experience as the orchestration engine hands off tasks.

Dynamic Reputation-Based Orchestration:

Our orchestrator uses real-time metrics to select agents, reroute tasks, and balance cost vs. quality dynamically. This adaptive system required building a custom reputation scoring engine that collects and analyzes agent performance data continuously.

Painless Web3 Onboarding:

To avoid the common friction of wallet creation, we integrated Privy’s Web3 social login that invisibly creates wallets in the background. Users can access blockchain features without knowing about keys or seed phrases initially, then gradually get introduced as power users.

How It All Fits Together

1 - A user logs in via social auth (Privy), which creates a blockchain wallet under the hood.

2 - They browse the agent marketplace on React frontend.

3 - When purchasing access, a transaction is sent through Hedera smart contracts, minting a time-limited access NFT.

4 - The backend orchestrates AI requests, routing user input to the appropriate OpenAI-powered agents based on the workflow.

5 - Conversation data and metadata are securely stored and shared via Walrus decentralized storage.

6 - The orchestrator engine dynamically manages task flow, agent selection, and context, ensuring smooth multi-agent collaboration.

7 - Creators receive automated payouts and maintain ownership of their AI agents.

This combination of decentralized blockchain tech, advanced AI orchestration, and seamless user experience through Web3 social onboarding is what makes Mosaic both unique and powerful.