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Lease a bridge

Leasing a bridge provides the Chromia bridge component instead of deploying it manually, replacing Deploy the Chromia bridge component in the bridge deployment guide.

You will still need an EVM bridge contract to interact with the leased bridge. See Deploy the EVM bridge component for details.

How leasing works​

To verify a bridge withdrawal transaction on the Chromia network from the EVM side, the EVM account must invoke the withdraw function on the Bridge smart contract and submit the block header for the block where the withdrawal was included, along with the block signatures for verification.

The Bridge then forwards the function call to the Validator Contract, which is responsible for interacting with the Chromia nodes. After the Validator Contract verifies the validity of the signatures, it returns the result of the operation to the EVM account. This process enables the verification of specific actions on the Chromia network.

The Validator Contract maintains a list of nodes and signers on the Chromia network. To prevent situations where the Validator Contract has an incorrect list due to updates in the Chromia network, it must be updated either manually by the developer or automatically by creating a bridge lease.

The leasing process​

The Bridge lease enables automatic updates to the node list in the Validator Contract. Each update incurs a transaction fee, paid in CHR tokens, converted at the current ETH exchange rate.

To initiate the process, visit Chromia Staking on mainnet or testnet and connect your wallet.

Next, click Containers lease in the header. In the container list, select the required container, click the overflow menu, and select Bridge lease.

bridge lease 1

Confirm your container selection by clicking Lease a bridge.

bridge lease 2

Specify all bridge details​

When leasing a bridge, you need to provide the following details:

  • EVM chain
  • Chromia destination chain
  • EVM Bridge contract address, from Deploy the EVM bridge component.
  • Validator contract address, depending on your target network, use:
    • BSC Testnet: 0x83dB85F7ef4447524D3A31c0F4664a89173C68Eb
    • BSC Mainnet: 0xc755927508b7Ac3f7B31c9Ed396F3bE91C723d00
    • Ethereum Mainnet: 0xc755927508b7Ac3f7B31c9Ed396F3bE91C723d00

Once all details are set, click Lease bridge to finalize the process.

bridge lease 3

Final step: Register the leased bridge on EVM​

After leasing the bridge, you need to register it on the EVM bridge contract.
Follow Register the Chromia bridge component on EVM to complete the setup.