Bridging adapters make a tokenized asset transferable across chains. Fireblocks deploys a Fungible LayerZero Adapter, a contract that wraps an ERC-20 token as a LayerZero OFT (Omnichain Fungible Token), grants it mint and burn permission on the token, and connects (links) it to the same token on another chain so cross-chain transfers work.
Prerequisites
- A deployed ERC-20F token on each chain you want to bridge between (the same token deployed on two or more networks).
- A vault account funded on each source chain to cover gas, unless you use the Relay (gasless) fee option.
- Bridging adapters enabled for your workspace.
Deploy and link a bridging adapter
Navigate to Financial apps > Tokenization > Tokens. This lists every token in your workspace, with its chain, total supply, contract address, and connected utilities. From here, you can also select + Create to deploy a new adapter or Link existing to attach a token to an adapter that's already deployed.
Select the token you want to make cross-chain. On the token's Overview, scroll to Applied token utilities and select Add a bridging adapter.
- On Deploy bridging adapter, select the tokens to link. The token you opened appears as the current token, with the peer token or tokens on the other chains listed below it. Configure each token's adapter:
- Adapter deployer: the vault account that deploys the adapter contract and pays gas.
- Fee: select Relay to route the deployment gaslessly through a relay or local relay from a vault account, or Direct to pay the fee on-chain yourself. Direct shows a tentative fee with Slow, Medium, Fast, and Custom speed options.
- Token mint/burn granter: the account that grants the adapter mint and burn rights on the token.
- Bridge administrator: the account that can update the bridge configuration, including DVNs (LayerZero's Decentralized Verifier Networks) and peers.
- Default admin: the adapter's default admin role.
Pauser: the account that can pause the adapter.
Leave a field as Default, or set it to a specific vault account or address. Repeat this for each linked token, then select Continue.
On Review adapter deployment, check the exact contracts and permissions Fireblocks is about to create. For each linked token, the deployment flow runs five steps: deploy the bridging adapter, grant mint permission on the token, grant burn permission on the token, connect the two tokens (set peers), and configure the DVN. Contract information summarizes your choices, including the contract template, token, and fee type. When everything looks correct, select Create adapter.
Fireblocks submits the deployment as a grouped set of transactions per chain, matching the five-step flow above. Track progress in the Recent activity panel, where each step is labeled Step X/5 with its on-chain confirmations. While the group runs, the token's Applied token utilities section shows the Fungible LayerZero Adapter as In progress.
- When both adapters are deployed and the connect (set peers) and DVN configuration transactions are finished, the tokens are ready to bridge. Open the adapter, Fungible LayerZero Adapter for [token name], to see the linked utility:
- Linked tokens: tokens actively bridged through this adapter.
- Applied on tokens: tokens this adapter is applied to.
Select + Link to add another peer token to the adapter later.
Once linked, you can transfer the token across the connected chains.
Additional notes
- Only one peer per native asset can be linked to an adapter at a time. LayerZero maps a single peer to each endpoint (chain).
- Relay deployments are gasless: no source-chain gas is drawn from a vault account. Direct deployments pay the on-chain fee directly and let you choose a speed.
- The bridge administrator controls DVNs, peers, and other privileged bridge configuration.