Tiny Rollup - A Minimal Solana L2 Rollup

A minimal implementation of a Solana L2 rollup that batches transactions and submits them to the Solana L1 for settlement.

Overview

Tiny Rollup is an educational implementation of a Layer 2 rollup on Solana that demonstrates:

• Transaction batching and sequencing
• State management with Merkle roots
• JSON-RPC interface compatibility
• L1 settlement via Solana transactions

🚀 Getting Started

Prerequisites

• Rust 1.70+
• Solana CLI (for local testing)

Installation

1. Clone and build:

git clone [email protected]:collin5/tiny-rollup.git
cd tiny-rollup
cargo build

2. Run with local Solana validator:

# Start local Solana validator
solana-test-validator

# Start the rollup
cargo run -- --solana-rpc http://localhost:8899 --port 8890 --db-path ./rollup_db

3. Run with Solana devnet:

cargo run -- --solana-rpc https://api.devnet.solana.com --port 8899 --db-path ./rollup_db

Testing with Curl

# Get latest blockhash
curl -X POST http://localhost:8899 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getLatestBlockhash",
    "params": []
  }'

# Get account balance
curl -X POST http://localhost:8899 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getBalance",
    "params": ["11111111111111111111111111111111"]
  }'

RPC Methods

• getAccountInfo - Get L2 account information
• getBalance - Get account balance in lamports
• sendTransaction - Submit transaction to L2
• getLatestBlockhash - Get current L2 blockhash
• simulateTransaction - Simulate transaction execution
• getTransaction - Get transaction details (TODO)

Current Features

• Transaction Processing: Validate and execute Solana transactions in L2
• State Management: In-memory + persistent storage with RocksDB
• Sequencer: Batch transactions every 2 seconds (up to 100 tx/batch)
• JSON-RPC Server: Compatible with Solana RPC methods
• L1 Submission: Submit batches to Solana mainnet/devnet
• Account Management: Basic lamports transfer between accounts

TODOS

Proper Merkle Tree State Roots

• Implement sparse Merkle tree for state commitments
• Generate proper state roots for L1 verification
• Add state root to batch submissions

Transaction Finality & Fraud Proofs

• Implement challenge period for fraud proofs
• Add state transition verification
• Create fraud proof generation

EVM/SVM Compatibility

• Add support for EVM bytecode execution
• Add cross-chain message passing