> For the complete documentation index, see [llms.txt](https://catoshi-tech.gitbook.io/catoshi-tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://catoshi-tech.gitbook.io/catoshi-tech/how-it-works/bridge-vaults.md).

# Bridge Vaults

#### Lock and unlock vault bridging. 

A smart contract vault resides on both chains holding 100% of tokens on primary chain and 60% of tokens on each additional chain.

In between the chains smart contracts is a node script server with advanced security and key management in place. The node script listens to any transfers that are made into the vault smart contracts.  If a token is successfully locked into the vault contract on chain A it will be unlocked from the vault on chain B and transferred to the users wallet.

The amount of circulating tokens can never be more that 100% of primary chain supply.

![](https://3793594520-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0zulqBnFItTjdB2LhsOj%2Fuploads%2FRAablSbmVMbbEmkQbk1d%2Fimage.png?alt=media\&token=492ae3d0-2db2-4834-b55b-82bd3845922b)

![](https://3793594520-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0zulqBnFItTjdB2LhsOj%2Fuploads%2F0zyMDtzDE47LsDMkl5Wt%2Fimage.png?alt=media\&token=1c05a4b3-d0da-48c5-aa2d-05c47faa4b1c)

Some blockchains have indexing issues so our node scripts have functions to handle blockchain indexing issues by re-triggering failed transactions.

#### Our vault contracts and node scripts have never lost a token and successfully bridged Trillions of tokens!