Panther Relayer overview


  • In return for a fee, Relayers provide an optional service to Protocol users β€” adding to the privacy set

  • Relayers pass bundles of transactions, signed and paid, to the Shielded Pool contract


Panther Relayers are specialist Operators providing a relaying and bundling service that run the (optional) Relayer service to provide an additional privacy layer by breaking the link between the initiator of the transaction and the transaction itself. Relayers earn rewards for:

  • signing the transactions with their public key

  • paying the gas fees

  • relaying bundles of transactions to the Shielded Pool contract

Relayers, therefore, enhance privacy, since observers are unable to pinpoint the actual address that initiated the transaction because the Relayer signs the underlying blockchain transaction with their key.

Supported transactions

As of testnet stage 6 and mainnet beta, Relayers support:

  • Account activation

  • Account renewal

  • Claiming PRP voucher

  • Deposit

  • Internal transfer

  • PRP to ZKP exchange

  • Withdrawal


The Relayer service leverages features introduced by the ERC-4337 standard such as tx (transaction) bundling and account abstraction.

Relayers pickup transaction relay requests and bundle these together. The details of this bundle are passed to the PayMaster contract which verifies the fee calculation. If the fee to be paid by the originator of each transaction is enough to cover the gas fees of the underlying platform, Matic for testnet and mainnet beta, then the PayMaster contract converts $ZKP from the pool of ZKP it controls into the native token, e.g. Matic using Uniswap's v3 service.

Note, PayMaster does this at intervals, not per bundle, to reduce fees.


Note that the fee calculation includes a buffer value, the failure fee. This ensures that the pool controlled by the PayMaster does not become depleted in the event of tx failures due to a re-org, gas-cost spike, or other impediment to tx success.

The gas fees are those fees charged by the blockchain, so Matic are required to pay tx costs in testnet and mainnet beta.

The zMiner fee pays the Ecosystem Operator that computes how to mine the transactions on-chain.


The gas fee charged by the Relayers includes their fee.

Service providers

Panther has integrated with Etherspot’s Skandha ERC4337 Relayer and Bundler service to send transactions to the blockchain. Users may select (Bundler = YES / NO) before submitting their transactions.

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