This document will help you answer the question: where can I find the logic for x? by giving a directory-tree style structure of the physical architecture of the zkSync Era project.
The zksync-2-dev repository has the following main units:
Smart Contracts: All the smart contracts in charge of the protocols on the L1 & L2. Some main contracts:
- L1 & L2 bridge contracts.
- The zkSync rollup contract on Ethereum.
- The L1 proof verifier contract.
Core App: The execution layer. A node running the zkSync network in charge of the following components:
- Monitoring the L1 smart contract for deposits or priority operations.
- Maintaining a mempool that receives transactions.
- Picking up transactions from the mempool, executing them in a VM, and changing the state accordingly.
- Generating zkSync chain blocks.
- Preparing circuits for executed blocks to be proved.
- Submitting blocks and proofs to the L1 smart contract.
- Exposing the Ethereum-compatible web3 API.
Prover App: The prover app takes blocks and metadata generated by the server and constructs a validity zk proof for them.
Storage Layer: The different components and subcomponents don't communicate with each other directly via APIs, rather via the single source of truth -- the db storage layer.
This section provides a physical map of folders & files in this repository.
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/contracts
/ethereum
: Smart contracts deployed on the Ethereum L1./zksync
: Smart contracts deployed on the zkSync L2.
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/core
-
/bin
: Executables for the microservices components comprising zkSync Core Node./admin-tools
: CLI tools for admin operations (e.g. restarting prover jobs)./external_node
: A read replica that can sync from the main node.
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/lib
: All the library crates used as dependencies of the binary crates above./basic_types
: Crate with essential zkSync primitive types./config
: All the configured values used by the different zkSync apps./contracts
: Contains definitions of commonly used smart contracts./crypto
: Cryptographical primitives used by the different zkSync crates./dal
: Data availability layer/migrations
: All the db migrations applied to create the storage layer./src
: Functionality to interact with the different db tables.
/eth_client
: Module providing an interface to interact with an Ethereum node./eth_signer
: Module to sign messages and txs./mempool
: Implementation of the zkSync transaction pool./merkle_tree
: Implementation of a sparse Merkle tree./mini_merkle_tree
: In-memory implementation of a sparse Merkle tree./multivm
: A wrapper over several versions of VM that have been used by the main node./object_store
: Abstraction for storing blobs outside the main data store./prometheus_exporter
: Prometheus data exporter./queued_job_processor
: An abstraction for async job processing/state
: A state keeper responsible for handling transaction execution and creating miniblocks and L1 batches./storage
: An encapsulated database interface./test_account
: A representation of zkSync account./types
: zkSync network operations, transactions, and common types./utils
: Miscellaneous helpers for zkSync crates./vlog
: zkSync logging utility./vm
: ULightweight out-of-circuit VM interface./web3_decl
: Declaration of the Web3 API.zksync_core/src
/api_server
Externally facing APIs./web3
: zkSync implementation of the Web3 API./tx_sender
: Helper module encapsulating the transaction processing logic.
/bin
: The executable main starting point for the zkSync server./consistency_checker
: zkSync watchdog./eth_sender
: Submits transactions to the zkSync smart contract./eth_watch
: Fetches data from the L1. for L2 censorship resistance./fee_monitor
: Monitors the ratio of fees collected by executing txs over the costs of interacting with Ethereum./fee_ticker
: Module to define the price components of L2 transactions./gas_adjuster
: Module to determine the fees to pay in txs containing blocks submitted to the L1./gas_tracker
: Module for predicting L1 gas cost for the Commit/PublishProof/Execute operations./metadata_calculator
: Module to maintain the zkSync state tree./state_keeper
: The sequencer. In charge of collecting the pending txs from the mempool, executing them in the VM, and sealing them in blocks./witness_generator
: Takes the sealed blocks and generates a Witness, the input for the prover containing the circuits to be proved.
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/tests
: Testing infrastructure for zkSync network./cross_external_nodes_checker
: A tool for checking external nodes consistency against the main node./loadnext
: An app for load testing the zkSync server./ts-integration
: Integration tests set implemented in TypeScript.
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-
/prover
: zkSync prover orchestrator application. -
/docker
: Project docker files. -
/bin
&/infrastructure
: Infrastructure scripts that help to work with zkSync applications. -
/etc
: Configuration files./env
:.env
files that contain environment variables for different configurations of zkSync Server / Prover.
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/keys
: Verification keys forcircuit
module. -
/sdk
: Implementation of client libraries for the zkSync network in different programming languages./zksync-rs
: Rust client library for zkSync.