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What is Hashi

Hashi is an EVM Hash Oracle Aggregator, designed to facilitate a principled approach to cross-chain bridge security.

The primary insight being that the vast majority of bridge-related security incidents could have had minimal impact if the systems relying on them had built in some redundancy. In other words, it's much more secure to require messages be validated by multiple independent mechanisms, rather than by just one.

Hashi aims to create “additive security” to cross-chain messages by aggregating block headers from different sources. A block header will be considered valid only when a number of block sources (oracles) above a certain threshold report the same result. Hashi is the first step towards a principled approached to bridges and will play a key role in the Gnosis Chain interoperability roadmap.


Oracles consists of the bridge solutions available in the market, such as AMB, Telepathy, Dendreth, etc. To provide an universal interface for Hashi, an adapter contract is designed specifically for each oracle. Some of the oracles require header reporter to report block header in certain slot.

Existing oracle adapters:

In progress:

Current deployments

Goerli -> Gnosis Chain

Hashi architecture

For the current configuration, we validate a Goerli block hash with 4 oracles, every ~15 mins.

The 4 oracles includes Telepathy Light Client, Dendreth Light Client, Gnosis AMB, and Sygma.
Threshold in ShoyuBashi is set to 2.

How to use it?
Call getThresholdHash(domain, blockNo) in ShoyuBashi.
By using domain=5 and blockNo a blockNumber that has been reported by the oracles, you get back the blockHash if at least 2 of the oracles have reported the same hash.

ContractDeployed onAddress
HashiGnosis Chain0xf59aedc291e0aF64943541709cdd041D992b4De4
ShoyuBashiGnosis Chain0x31a8E89D6f98454D38C03eCA3DC543F6581d607C
HeaderStorageGnosis Chain0xB256d8a90852DBb222653ab89b611c2426011C0D
AMB Header ReporterGnosis Chain0x5DE3417a21eEd340836C9c1339913b60743b3470
AMB AdapterGnosis Chain0x32Cd442309cA6E79Db2194aac61024FBD2B14eb9
AMBGnosis Chain0x9f696CF3c1a0A418cBBFD6E1ab3EBe8A78971Dea
Telepathy AdapterGnosis Chain0x2f1E51a2763FB67fe09971Fd8d849716137A3357
Telepathy Light ClientGnosis Chain0x34b5378DE786389a477b40dD710812c250185f83
Sygma AdapterGnosis Chain0x9AD7a6f4FDA8247cC0bF5932B68c5b619937dB15
SygmaGnosis Chain0xd2d95f7611c83b1f9041539557810033aC7B8742
Dendreth AdapterGnosis Chain0x719523EaF5CFd101Ef501C64597613FBB7aEdED9
Dendreh Light ClientGnosis Chain0x983df74d1ef68b4ff1fff11a28c06e5c097435da
AMB Header ReporterGoerli0xedc0b1d3de4496e0d917af42f29cb71eb2982319
Sygma Header ReporterGoerli0x2f96d347c932ac73b56e9352ecc0707e25173d88

Goerli -> Chiado

For the current deployment, only AMB and Telepathy oracles are supported.

ContractDeployed onAddress
AMB AdapterChiado0x02EF808c1235EC235BdfEf9b5768527D86093711
Telepathy AdapterChiado0xAED11f08AB2C45C6C6DF242B8513c7919E0A0f8f
Telepathy Light ClientChiado0xb1D85B0122C9CE0a68fDC6620a7416c77f984425
AMB Header ReporterGoerli0x61fac58f793b2a8a791a0583618feb89e256e839