Introducing Telepathy

The first decentralized and secure zkSNARK interoperability protocol for Ethereum.

Telepathy enables interoperability without compromise. Built with zkSNARKs, Telepathy allows developers to trustlessly communicate from Ethereum to any other chain with the security of Ethereum's light client protocol, without resorting to less secure multisigs or centralized actors. Live on Ethereum mainnet today. Start building with Telepathy on Ethereum mainnet and 8 supported EVM chains at Check out our demo at Fill out this form to become an early partner.

Wen Mainnet? Mainnet Now.

At Succinct, we’ve been hard at work over the past year for the mainnet launch of Telepathy. Telepathy is Ethereum’s first zkSNARK interoperability protocol secured by proof of consensus. Today, developers can use Telepathy to read Ethereum state on any other chain without any centralized actors in-between. Recent developments in zero-knowledge proofs allow for us to generate a succinct "proof of consensus"--allowing smart contracts on other chains to directly validate Ethereum state by running a gas-efficient light client.

Developers can get started building with Telepathy today at: Try sending a cross-chain message with our demo and check its status on our message explorer. The protocol is currently live on Ethereum Mainnet and 8 supported chains (Mainnet, Goerli, Gnosis, Polygon, Binance Smart Chain, Avalanche, Arbitrum and Optimism) and available for anyone to use.

Security and transparency matter to us. Our protocol has 3 audits from top firms: VeridiseTrail of Bits and Zellic, and a bug bounty program that will be launching soon with Immunifi. The code is also fully open-sourced: the smart contracts are here and the zkSNARK circuits are here. A detailed description of the protocol is here.

To our knowledge, this is the first mainnet deployment of “zk-bridging” from Ethereum--a concept that people have been talking about for a long time, but is finally in production. This is just the first step in Succinct’s long journey in building the end-game of interoperability powered by zkSNARK proof of consensus.

We have some exciting early partners who are using Telepathy’s messaging protocol for a variety of applications. Keep an eye out and follow our Twitter for announcements. If you want to become an early partner in using our protocol, which includes prioritized Succinct support and other help, please fill out this form. We also have a list of exciting application ideas in the section below. Please fill out the above form if you’re interested in building any of those.

Why we're building Telepathy

The status quo of bridging and interoperability is broken. Centralized designs are not censorship resistant and place immense trust on a small set of trusted parties. Furthermore, these centralized bridges have been much less secure than the underlying blockchains that they are bridging between. Billions of dollars have been hacked from cross-chain bridges and the largest hack to date ($600M in the Ronin bridge) was due to key compromise of a multisig.

At Succinct, we firmly believe that decentralized, permissionless systems that do not require trust in centralized entities are the foundation of the blockchain substrate. Security is defined by the weakest link and the current state of interchain messaging leaves a lot to be desired. If we are building the foundations of a new global financial system, it is unacceptable to rely on a small subset of centralized actors for such a mission-critical component. The status quo of permissioned multisigs is broken and unsustainable for the long-term future of the crypto industry as a whole.

The launch of our zkSNARK Ethereum light client powering Telepathy is only the first-step in a long journey. At Succinct our mission is to build an uncompromising interoperability protocol that is unstoppable, permissionless, credibly neutral and controlled by no one company or entity. The blockchain space is one of the few opportunities teams have to build a protocol that lasts beyond the confines of a company or even beyond any one lifetime. We want to build an interoperability protocol that lives for as long as Ethereum itself.

A Deeper Dive into the Telepathy Protocol

In math we trust

As we've written about before, we believe that the gold-standard of interoperability is on-chain succinct light clients that efficiently verify a source chain's consensus in the execution layer of a target chain. This approach inherits the security of the source chain and does not impose any additional trust assumptions on bridging. Because light clients are computationally expensive and generally unfit for the resource constrained environment of a blockchain, we use zkSNARK proofs to make on-chain light clients gas-efficient.

The Telepathy System

When using Telepathy, there is no centralized, trusted entity involved in the transmission of messages between Ethereum and destination chains. Our light client smart contract is entirely permissionless and our zkSNARK circuits are open source, so anyone can generate the proofs needed to update the light client. We have no permissioned provers or operators. The step(...) and rotate(...) functions in the Light Client are external with no access control modifiers--meaning anyone is free to submit updates to the light client. Our light client verifies the Ethereum light client protocol, aka the Sync Committee, described here.

Our messaging system allows anyone to relay messages by generating the appropriate Merkle proofs, which are verified on-chain against block headers in the light client. The executeMessageFromLog(...) function in the TargetAMB contract has no access control modifiers (except a re-entrancy) allowing anyone to relay a message with the correct Merkle proofs.

For a detailed, technical discussion of our protocol and the Ethereum light client protocol, please read this section of the docs.

The table below compares Succinct with other interoperability solutions available today.

Bridge Type Latency Security Permissionless
Multisig Low Trust small number of entities Permissioned
Optimistic High (hours to days long fraud window) Fraud proof economic game Permissioned updater and watcher set
Proof of Consensus (Telepathy) 1-2 minutes Ethereum light client protocol Permissionless

In the short-term, we recognize that the technology we're deploying is complex and no audit is guaranteed to find all potential security issues. Because of this, our initial deployment of Telepathy contains certain guardrails that we intend on removing in the long-term as the protocol matures. In particular, Telepathy contains one permissioned function allowing the Succinct team to freeze the protocol in the case of an exploit.

Similar to how rollups must have upgradeability for Ethereum execution layer changes, Telepathy must have upgradeability for Ethereum consensus layer changes. Our messaging layer is upgradeable with a 7 day timelock, allowing for ample exit time. We intend on decentralizing this upgradeability authority over time. This section of the docs goes through a detailed explanation of all guardrails and permissioned functions.

Exciting Application Ideas

A short list of ideas the Succinct team is excited by and wants to help developers interested in building these with Telepathy!

Messaging from Ethereum Outwards

Telepathy lets you send messages from Ethereum to any other chain (interchain messaging docs). Here are some interesting potential applications of unidirectional messaging:

Cross-chain governance: Decentralized, censorship resistance cross-chain governance is an important primitive, not well served by the bridging status quo. Any protocol with governance with voting on Ethereum that needs to control parameters of a deployment on another chain can use Telepathy as its governance bridge.

Cross-chain collateral: Users often want to use assets on one chain as collateral on another. Instead of requiring users to bridge funds to use as collateral, allow users to lock collateral in a smart contract on Ethereum and send a message through Telepathy attesting that their collateral is locked.

Cross-chain RFQ: Users might have collateral on a non-Ethereum chain they want to swap for assets on Ethereum. Users can lock funds on the alternative chain to open up an RFQ. A counterparty can fill the swapper on Ethereum, by sending them assets thereby triggering a message sent through Telepathy to unlock the user's assets on the other chain.

Ethereum State Reads

Telepathy lets you read Ethereum state on any other chain trustlessly, inspiring a variety of interesting applications (Ethereum Data Oracle docs):

Cross-chain naming service: ENS and other popular naming services have registries on Ethereum. Telepathy’s Ethereum state reads allow dapps trustless and composable access to any on-chain registry on Ethereum in the execution layer of any other chain.

Cross-chain airdrop: dApp developers on new chains might want to incentivize large users of similar Ethereum protocols. With Telepathy, developers can read Ethereum state on any chain to determine Ethereum user's positions and behavior, and accordingly incentivize those users to use their new protocol.

NFT-bridging: Fully on-chain games might have their core assets on Ethereum but have game play and execution live on chain with cheap blockspace. The on-chain game can use the Telepathy Ethereum oracle to check for ownership of particular in-game assets or NFTs on Ethereum as a gating mechanism for gameplay on the gaming chain.

Ethereum Consensus Beacon Oracle

Not only does Telepathy give you access to Ethereum state on any other chain, it also gives you access to the consensus layer of Ethereum on Ethereum itself (Beacon Oracle Docs). This has been a long-requested EIP (, but with Telepathy, you can query for any state in the Beacon chain consensus layer directly in the execution layer today.

Replacing liquid staking oracles: Many liquid staking services have centralized oracles to update validator balances in their smart contracts. Telepathy's Beacon Oracle allows smart contracts trustless access to validator balances and other validator statistics, including whether they were slashed or not, whether they successfully proposed a block, etc. on-chain.

Credible MEV commitments: The consensus block header from the Telepathy Beacon oracle allows for on-chain verification of statements asserting that a certain validator placed a transaction from a particular searcher at the top of a block. This information can also be used composably in other smart contracts.

Because Gnosis Chain also uses Ethereum consensus, we can actually send messages bi-directionally between Gnosis Chain and Ethereum! Beyond the obvious use-case of securing the bridge between Ethereum and Gnosis Chain with Telepathy, here are a few interesting ideas we had in mind!

Snapshot voting on Gnosis: Snapshot voting is generally done off-chain as a “temperature check” before on-chain voting on mainnet. Gnosis chain is a cheap computational environment where Snapshot voting could be conducted on-chain and the results transmitted back to Ethereum using Telepathy.

Offloaded expensive computation, such as neural networks, on Gnosis Chain: Gnosis Chain’s cheap execution environment can allow for interesting and uncommon blockchain use-cases like an on-chain neural network to be run. The data fed into the computation can be from mainnet and the result can be sent back to mainnet using Telepathy. -->

If you’re interested in building one of these, please get started with the Telepathy Docs) and also fill out the early partner form and we can give you special help! If your chain or ecosystem wants to be added to the list of supported Telepathy chains, fill out the early partner form as well!


A few teasers of what to expect from the Succinct team in the upcoming weeks and months!

Early Partners: We have a few early partners that have been early users of Telepathy, that we will be announcing in the next few weeks! Follow our Twitter for updates as we announce these partnerships!

Grants Program: We believe that client diversity in bridge implementations is critical for the long-term security and success of proof of consensus bridging. We are quite proud of the work we have done for our existing zkSNARK circuit, but believe zkSNARK circuit client diversity is the correct long-term approach for improved security. True client diversity means that other implementations should not be built in-house by us! To encourage this, we will be launching a grants program with mentorship to help others build these circuits.