Philosophy

zkSync Era–specific primitives. The zks_* RPC namespace, the system-contract bindings (NonceHolder, ContractDeployer, L1Messenger, L2 Bridgehub), the EIP-712 (0x71) transaction encoder + signer, per-chain L1 deployment registry, and the L1↔L2 bridge verbs — everything that's true of every zkSync Era chain (Era mainnet, Sepolia testnet, and the ZK-chain ecosystem) but isn't part of L1 Ethereum.

The Yellow-Paper substrate — accounts, EVM, RLP, EIP-1559, the eth_* method surface — stays in @ethernauta/eth. This package is the layer on top.

Modules

• arbitrum [NPM]
• op [NPM]
• zksync [NPM]

API

zks_* RPC — Readable<T>

import {
  zks_estimateFee,
  zks_estimateGasL1ToL2,
  zks_getBridgehubContract,
  zks_getMainContract,
  zks_getBridgeContracts,
  zks_L1ChainId,
  zks_L1BatchNumber,
  zks_getBlockDetails,
  zks_getL2ToL1MsgProof,
  // …
} from "@ethernauta/zksync"

The full zks_* consensus-side surface — fee estimation, batch/block details, L1↔L2 message proofs.

EIP-712 transaction type 0x71

import {
  encode_zksync_transaction,
  hash_zksync_transaction,
  build_zksync_typed_data,
  sign_zksync_transaction,
  ZKSYNC_TRANSACTION_TYPE,
} from "@ethernauta/zksync"

The zkSync-specific transaction envelope with paymaster, factoryDeps, and customSignature fields. Composes with @ethernauta/crypto for the actual signing primitive.

System contracts

import {
  NonceHolder,         // 0x...8003
  ContractDeployer,    // 0x...8006
  L1Messenger,         // 0x...8008
  BridgehubL2,
  L2BaseToken,
  L2AssetRouter,
} from "@ethernauta/zksync"

Callable<T> / Signable<T> bindings against the fixed-address system contracts living at the 0x000…000{80xx} range.

Per-chain L1 deploys

import { require_deploy_addresses } from "@ethernauta/zksync"
import { eip155_324 } from "@ethernauta/chain/eip155-324"

const deploys = require_deploy_addresses(eip155_324)
// { bridgehub, diamondProxy, sharedBridge, l1AssetRouter, l1Nullifier, … }

L1 deployment addresses for zkSync Era mainnet and Sepolia.

Bridge verbs — Bridgeable<T>

import {
  send_eth,
  send_erc20,
  send_message,
  start_withdraw_eth,
  start_withdraw_erc20,
  start_withdraw_message,
  execute_withdraw,
  claim_failed_deposit,
  fetch_message_proof,
  fetch_failed_deposit_proof,
  get_status,
  decode_l1_message_sent,
  decode_new_priority_request,
} from "@ethernauta/zksync/bridge"

import { create_bridge } from "@ethernauta/transport"

const bridge = create_bridge(CHAINS)({
  l1_chain_id: ETH_MAINNET,
  l2_chain_id: ZKSYNC_ERA,
})

const hash = await send_eth({ to, value })(bridge.signer)

Covers L1 → L2 deposits via the Bridgehub, the claim_failed_deposit escape hatch for reverted deposits, L2 → L1 withdrawals (start on L2 via the L1Messenger, execute on L1 via the L1Nullifier), and event decoders for parsing L1MessageSent / NewPriorityRequest off the receipts. Errors are typed.

Solidity sources

The vendored zkSync system contracts and bridge contracts live colocated under packages/zksync/src/system-contracts/<contract>/ and packages/zksync/src/bridge/<contract>/. pnpm pull-contracts refreshes them from the upstream repo; pnpm pull-deploys regenerates the per-chain L1 deploys registry.