NEXUS Network

Bitcoin, but useful. A proof-of-useful-work blockchain where validators solve real optimization problems instead of wasteful hash puzzles.

Overview

NEXUS replaces Bitcoin's SHA-256 mining with Ising model optimization - the same mathematical framework used for protein folding, drug discovery, and logistics optimization. Miners submit zero-knowledge proofs (Nova/Halo2) that verify their computational work without revealing solutions.

Key Features

• Proof of Useful Work: Solve real-world optimization problems
• Zero-Knowledge Proofs: Nova recursive SNARKs verify work in ~10 seconds
• 20-Year Emission Schedule: 75B NEX distributed to miners
• Dual Fee Burn: 2% job fees + 50% transaction fees burned
• 80/20 Split: Miners get 80%, validators get 20%
• 2-Second Finality: CometBFT consensus with instant finality

Quick Start

Prerequisites

• Go 1.22+
• jq

Build

git clone https://github.com/tomdif/nexus-chain.git
cd nexus-chain
go build -o nexusd ./cmd/nexusd/

Run Single Node

./nexusd init my-validator
./nexusd start

Run 3-Node Testnet

./scripts/testnet.sh      # Initialize
./scripts/start-testnet.sh # Start all nodes
./scripts/stop-testnet.sh  # Stop all nodes

CLI Commands

Transactions

# Post a paid optimization job
nexusd tx mining post-job <problem-hash> <threshold> <reward> --priority-fee 100000

# Submit proof for a job
nexusd tx mining submit-proof <job-id> <solution-hash> <energy> <proof-base64>

# Submit free public research job
nexusd tx mining submit-public-job <title> <category> <hash> <threshold> <ipfs-cid>

# Claim mining rewards
nexusd tx mining claim-rewards <job-id>

# Cancel job and get refund
nexusd tx mining cancel-job <job-id>

Queries

nexusd query mining get-job <job-id>
nexusd query mining list-jobs
nexusd query mining get-miner <address>
nexusd query mining get-params
nexusd query mining get-active-job
nexusd query mining get-queue-status
nexusd query mining get-emission-info

Architecture

┌─────────────────────────────────────────────────────────────┐
│                      NEXUS Network                          │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────┐  │
│  │   Mining    │  │   Staking   │  │   Bank (NEX Token)  │  │
│  │   Module    │  │   Module    │  │      Module         │  │
│  └──────┬──────┘  └──────┬──────┘  └──────────┬──────────┘  │
│         │                │                     │             │
│  ┌──────▼────────────────▼─────────────────────▼──────────┐ │
│  │                    Cosmos SDK v0.50                    │ │
│  └────────────────────────┬───────────────────────────────┘ │
│                           │                                  │
│  ┌────────────────────────▼───────────────────────────────┐ │
│  │                  CometBFT v0.38.9                      │ │
│  │            (Byzantine Fault Tolerant Consensus)        │ │
│  └────────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────┘

Tokenomics

Parameter	Value
Token	NEX
Denomination	unexus (1 NEX = 1,000,000 unexus)
Total Supply	100B NEX
Initial Allocation	25B NEX (founders/treasury)
Mining Emissions	75B NEX over 20+ years
Job Fee Burn	2%
Transaction Fee Burn	50%

Emission Schedule

Years	Rate (NEX/min)	% of Max
1-2	35,950	100%
3-4	17,975	50%
5-6	8,988	25%
7-8	4,494	12.5%
9-10	2,229	6.2%
11-12	1,114	3.1%
13+	539	Perpetual

Job System

Job Types

1. Paid Jobs: Customers pay NEX for priority computation

   • Priority fee determines queue position
   • Full reward + emission bonus to solver

2. Public Jobs: Free research problems (requires stake)

   • Random selection from queue
   • Emission rewards only

3. Synthetic Jobs: Auto-generated when queues empty

   • Ising problems from block hash
   • Keeps miners productive

Job Flow

Customer → Post Job → Priority Queue → Active Job → Miner Solves
                ↓                            ↓
         2% Fee Burned              ZK Proof Verified
                                           ↓
                                    Rewards Distributed
                                    (80% Miner, 20% Validators)

ZK Proof Integration

NEXUS uses Nova recursive SNARKs to verify optimization work:

Miner                          NEXUS Chain
  │                                 │
  │  Solve Ising Problem            │
  │  Generate Nova Proof            │
  │                                 │
  │──── Submit Proof ──────────────►│
  │                                 │
  │     POST /verify                │
  │     ┌──────────────────────┐    │
  │     │ Nova Verifier Service│    │
  │     │ (localhost:3000)     │    │
  │     └──────────────────────┘    │
  │                                 │
  │◄─── Rewards if Valid ──────────│

Network Ports

Node	P2P Port	RPC Port
Node 1	26656	26657
Node 2	26666	26667
Node 3	26676	26677

Development

Run Tests

go test ./x/mining/keeper/...

Project Structure

nexus-chain/
├── app/                    # Application wiring
│   ├── app.go             # Main app definition
│   └── ante/              # Transaction preprocessing
├── cmd/nexusd/            # CLI entry point
├── scripts/               # Testnet scripts
├── x/mining/              # Mining module
│   ├── client/cli/        # CLI commands
│   ├── keeper/            # State management
│   │   ├── msg_server.go  # Transaction handlers
│   │   ├── query_server.go# Query handlers
│   │   ├── emissions.go   # Emission schedule
│   │   └── background_jobs.go # Job queues
│   └── types/             # Type definitions
└── docs/                  # Documentation

License

MIT

Links

• GitHub
• ZK Proof System