ZetaChain has two types of validators: core validators and observer-signer validators (observer-signers).

ZetaChain is designed to have two types of validators: observers and signers. Observers monitor activities on connected chains, while signers handle the signing of transactions from the Threshold Signature Scheme (TSS) address on behalf of the protocol. However, currently, all observer-signer validators on ZetaChain perform both roles, acting as both observers and signers. This means each observer-signer validator simultaneously observes transactions on connected chains and participates in transaction signing.

Observer-signers are tasked with running nodes of connected chains, observing them with zetaclient and writing transactions to connected chains.

The protocol is designed in a way to allow observer-signers in the future to choose which chains they want to observe. This allows for a more flexible system where observer-signers can observe only the subset of chains they are interested in (for example, their infrastructure is built around running EVM nodes). In the current version of the protocol, all observers-signers are observing all chains.

A list of observer-signers on the ZetaChain testnet:

As they perform a critical function in the system, the minimum self delegation/stake required to be an observer-signer is set as a param of the observer module on a per chain basis. This is to ensure that observer-signer validators are incentivized to perform their duties and are not malicious.