Transaction fees

Transaction fees on the Botanix EVM are a little different from Bitcoin and resemble more the Ethereum network.

There are 3 primary actions when interacting with the Botanix EVM that can result in transaction fees.

• Layer 2 transactions (i.e. transactions on the Botanix EVM itself)

• Layer 1 to Layer 2 transactions (i.e. transactions from the Bitcoin main chain to Botanix EVM = bridge-in)

• Layer 2 to Layer 1 transactions (i.e. transactions from Botanix EVM to the main chain = bridge-out)

Gas fees

Fees on the Botanix EVM are denominated in bitcoin. This also means that the staking rewards for the Spiderchain stakers, or Orchestrators, will receive their staking rewards in bitcoin.

The formula is the same as what you see on the Ethereum platform.

• Fee = transaction.gasPrice * gasUsed

You should use eth_gasPrice to determine the appropriate gas price needed. Also, eth_estimateGas is used to find an appropriate gas limit.

• Note that if the transaction.gasPrice is too low, your transaction will be rejected.

• If you supply a transaction.gasLimit less than the value of eth_estimateGas, your transaction will be rejected.

Layer 1 <> Layer 2

Fees for Layer 1 to Layer 2 Transactions

When you create an L1 to L2 transaction (i.e. bridge-in), you need to pay for:

1. The standard bitcoin transaction cost (This you will find in your BTC wallet of choice)

2. The gas cost to call the minting contract (Shown on our bridge)

The cost of the initialization transaction depends on the mempool and current L1 congestion level. The cost of the finalization transaction is determined in the same way as any other L2 transaction.

Fees for Layer 2 to Layer 1 Transactions

When you want to withdraw your funds back to L1 (i.e. bridge-out), you need to pay essentially for the same things as when you bridge-in. The biggest difference here is that we will batch all outgoing transactions which could lead to lower fees and both steps are automated.

A transaction from L2 to L1 will consist of the following:

• A Layer 2 transaction that initiates the burning on the Botanix EVM.

• A Layer 1 transaction on bitcoin that returns the bitcoin to you.

The cost of the initialization transaction is determined in the same way as any other L2 transaction. The cost of the finalization transaction depends on the mempool and current L1 congestion level.