smom-dbis-138/docs/operations/status-reports/FORK_ANALYSIS.md

Fork Analysis: Can We Use Mainnet WETH9 Address?

Question: If ChainID 138 is a fork of Ethereum Mainnet, can we use the existing WETH9 address?

Answer: ✅ YES - If it's a fork, WETH9 already exists at the Mainnet address!

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Understanding Forks

What is a Fork?

A fork of Ethereum Mainnet means:

• The new chain starts with a copy of Mainnet's state at a specific block
• All existing contracts are preserved at their original addresses
• All account balances and contract storage are preserved
• The chain then diverges from that point

What is a New Chain?

A new chain (not a fork) means:

• Starts with empty state (genesis block)
• No existing contracts
• Must deploy all contracts from scratch
• Addresses will be different

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Current Status: ChainID 138

Genesis Configuration Analysis

Looking at config/genesis.json:

• Chain ID: 138 (different from Mainnet's 1)
• Consensus: QBFT 2.0 (different from Mainnet's Proof of Stake)
• Alloc: Limited pre-allocated accounts
• WETH9 Address: Not found in genesis

Conclusion: NOT a Fork

Based on the genesis configuration, ChainID 138 appears to be a NEW chain, not a fork:

• Different consensus mechanism (QBFT 2.0 vs PoS)
• Different chain ID (138 vs 1)
• No Mainnet state included
• WETH9 address not in genesis

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If We Made It a Fork

Option 1: Fork at a Specific Block

If we configure ChainID 138 as a fork of Ethereum Mainnet:

{
  "config": {
    "chainId": 138,
    "berlinBlock": 0,
    "londonBlock": 0,
    "istanbulBlock": 0,
    "qbft2": { ... }
  },
  "alloc": {
    // Mainnet state at fork block would be included
    "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2": {
      "balance": "...",
      "code": "...",  // WETH9 bytecode
      "storage": { ... }  // WETH9 storage
    }
  }
}

Result:

• ✅ WETH9 exists at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
• ✅ No deployment needed
• ✅ Same address as Mainnet
• ✅ All Mainnet contracts available

Option 2: Use Besu's Fork Configuration

Hyperledger Besu supports forking Ethereum Mainnet:

# besu-config.toml
genesis-file="/config/genesis.json"
fork-block-number=18000000  # Fork at block 18,000,000

Result:

• ✅ Mainnet state preserved
• ✅ WETH9 at original address
• ✅ All contracts available

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Current Implementation: New Chain

Since ChainID 138 is configured as a new chain (not a fork):

Implications:

1. ❌ WETH9 does NOT exist
2. ❌ Must deploy WETH9
3. ❌ Address will be different from Mainnet
4. ✅ Full control over chain state
5. ✅ Custom consensus (QBFT 2.0)

Deployment Options:

1. Deploy with CREATE: New address (current method)
2. Deploy with CREATE2: Deterministic address (but still different from Mainnet)
3. Fork Mainnet: WETH9 already exists (requires genesis reconfiguration)

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Recommendation

If You Want WETH9 at Mainnet Address:

Option A: Reconfigure as Fork

1. Update genesis.json to include Mainnet state
2. Configure Besu to fork from a specific Mainnet block
3. WETH9 will exist at 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
4. No deployment needed

Option B: Keep as New Chain

1. Deploy WETH9 with CREATE or CREATE2
2. Document the new address
3. Users will use the new address on ChainID 138

Trade-offs:

Aspect	Fork	New Chain
WETH9 Address	✅ Same as Mainnet	❌ Different
Mainnet Contracts	✅ All available	❌ Must deploy
State Size	⚠️ Large (full Mainnet state)	✅ Small (empty)
Control	⚠️ Limited (inherits Mainnet state)	✅ Full control
Consensus	⚠️ Must match Mainnet	✅ Custom (QBFT 2.0)

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Next Steps

1. Decide: Fork or New Chain?
2. If Fork: Update genesis.json with Mainnet state
3. If New Chain: Continue with current deployment method
4. Document: Clearly state whether it's a fork or new chain

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Conclusion

Current Status: ChainID 138 is a NEW CHAIN, not a fork.

To Use Mainnet WETH9 Address: Reconfigure as a fork of Ethereum Mainnet.

Otherwise: Deploy WETH9 and use the new address.