Overview
This section of the docs provides a detailed analysis of the full topology of the Polygon zero-knowledge system architecture.
Tailored for CDK stacks and using zkEVM technology, these documents explore the contents, layout, and interactions among component systems and functions. They offer in-depth descriptions of the components that constitute the larger system, with references to relevant code bases.
The diagram below is a full and detailed topological overview of the entire Polygon zero-knowledge system architecture.
Architectural topology¶
Components¶
- Smart contracts: L1 and L2 Solidity smart contracts used for interacting with the whole stack.
- Exit root trees: Append-only sparse Merkle trees which record the current and historical state of the system.
- CDK and zkEVM nodes containing:
- JSON RPC client: Exposes the read/write interfaces for interacting with a node/chain.
- Pool database: Records transaction requests coming in from the JSON RPC client and passes them to the sequencer.
- State database: Responds to read requests from the JSON RPC client.
- Sequencer: Does the complex job of fetching transactions and carefully sequencing them before sending them to the aggregator for batching. See the discussion on sequencers for more information.
- Aggregator: Aggregates transaction batches to send to the prover. See the discussion on aggregators for more information.
- Synchronizer: Ensures a synchronized state between the node’s systems and the L1 outside-world via the Etherman component and the state database.
- Etherman: Helps the synchronizer maintain a synchronized state with L1 by communicating with the L1 Ethereum chain via smart contract functions.
- Unified bridge service: Provides an API to perform bridge claims, i.e. asset and message transfers between L1/L2 and L2/L2.
- Prover: System for calculating zero-knowledge proofs on transaction batches.
What to expect¶
When complete, this section will include information on:
- The structure of a CDK node and how it interacts with L2 and L1 smart contracts.
- The structure of a zkEVM node and how it interacts with L2 and L1 smart contracts.
- The key components included in the nodes, how they function, and their interactions with other components, external dApps, and the L1/L2 environment.
- Key similarities and differences between a CDK and zkEVM node.
- CDK validium components, including the DAC and DAC sequencer.
- Detailed description of the Polygon smart contract sets for L1 and L2.
- The zkProver and how it interacts with a zkEVM node aggregator.
Currently out of scope¶
- The in-development bridge service.
- AggLayer.