> For the complete documentation index, see [llms.txt](https://docs.nucleusearn.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/multi-chain-teller-base/chain.md).

# Chain

[Git Source](https://github.com/Ion-Protocol/nucleus-boring-vault/blob/cc0b494b83e17b9b169a73b96050d2810b690477/src/base/Roles/CrossChain/MultiChainTellerBase.sol)

```solidity
struct Chain {
    bool allowMessagesFrom;
    bool allowMessagesTo;
    address targetTeller;
    uint64 messageGasLimit;
    uint64 minimumMessageGas;
}
```