Astar zkEVM Guide: Polygon CDK Layer 2 Explained

Astar zkEVM is an Ethereum layer-2 network that was developed by the team behind Astar Network and built with the Polygon Chain Development Kit (CDK). It executes EVM-compatible smart contracts off Ethereum mainnet, groups transactions into batches, and uses zero-knowledge proofs to show that the resulting state changes are valid. Those proofs and the associated data are posted to Ethereum, which acts as the settlement layer.

For users, the practical meaning is simple:

• EVM compatibility. Wallets such as MetaMask, Solidity contracts and common developer tools work with little or no change.
• Lower fees than Ethereum mainnet. Costs are spread across many transactions in a batch, though exact fees vary with network load and Ethereum data costs.
• Ethereum-anchored security. Validity proofs are checked on Ethereum, so invalid state transitions should not be accepted. The security of funds still depends on bridge contracts, the proving system and how transaction data is made available.

The chain was positioned as a place for DeFi, gaming and consumer apps, with Astar's existing developer community in Japan and across Asia as a core audience. Its testnet was called Zkatana, and a mainnet followed.

This guide is deliberately evergreen. Layer-2 networks change quickly: bridges can be paused, products can be migrated and chains can be consolidated. Anything that depends on the present moment, such as whether the network is live, which dApps are deployed or what fees cost today, should be checked in the official Astar documentation and announcements before you act.

The name causes confusion because Astar runs more than one network.

Astar Network (Polkadot). This is the original chain, a Polkadot parachain that grew out of the earlier Plasm project. It supports both EVM contracts and WebAssembly (WASM) contracts and has its own token, ASTR. It is known for dApp staking, where token holders stake on applications and the applications earn rewards, a model sometimes described as a basic income for builders.

Astar zkEVM (Ethereum L2). This is a separate chain with its own state, its own bridge and its own address space for assets. It was built with Polygon CDK, connects to Ethereum rather than Polkadot, and uses ETH for gas. Holding ASTR on the Polkadot parachain does not give you a balance on the zkEVM chain.

Soneium. Astar's team has also been publicly associated with Soneium, an Ethereum layer 2 led by Sony Block Solutions Labs in partnership with Startale. Soneium is a different network with different technology. It is mentioned here because readers researching Astar often encounter it, and because the team's attention can shift between projects. Do not assume that a feature, token incentive or bridge on one network applies to another.

A useful rule: always identify which of these networks a guide, bridge page or airdrop announcement refers to, and confirm the chain ID and contract addresses in official documentation before signing anything.

Astar zkEVM follows the general zk-rollup pattern, using components from Polygon CDK.

1. Users send transactions to the network through a normal EVM wallet and RPC endpoint.
2. A sequencer orders transactions and produces blocks quickly, which is why confirmations feel fast on the chain itself.
3. Transactions are batched and a prover generates a zero-knowledge proof that executing the batch from the previous state produces the new state.
4. The proof is verified by a contract on Ethereum, which updates the chain's state root. Once verified, the batch is considered finalised on Ethereum.
5. Data availability determines whether the underlying transaction data can be reconstructed by anyone. Polygon CDK chains can be configured as rollups, which publish data to Ethereum, or as validiums, which keep data with a separate committee or service and are cheaper but add a trust assumption. Check the official documentation for the mode Astar zkEVM used.

Polygon CDK chains are also designed to connect to Polygon's shared bridging infrastructure, often called the unified bridge or AggLayer. This is intended to let assets and messages move between connected chains with less friction than a traditional bridge.

Two trust points matter most to users. First, the sequencer is typically operated by a single party, so transaction ordering and uptime depend on that operator. Second, upgrade keys on the bridge and rollup contracts may allow the operators to change the system. Both are common in early-stage layer 2s and are worth understanding before depositing large amounts.

The table below summarises the stable design features. Items marked as needing verification can change, so confirm them in official documentation.

Feature	What to know
Network type	Ethereum layer 2 using zero-knowledge validity proofs
Built with	Polygon Chain Development Kit (CDK)
Settlement layer	Ethereum
Smart contract language	Solidity and other EVM-compatible tooling
Gas token	ETH (verify in current docs)
Data availability	Rollup or validium mode depends on configuration; verify
Native Astar token	ASTR belongs to Astar Network on Polkadot, not the zkEVM's gas
Test network	Zkatana, used by developers before mainnet
Chain ID and RPC	Copy from official docs only, never from search ads or social posts

What EVM compatibility means. Most Ethereum dApps can be deployed with minimal changes, but zkEVMs can differ in small ways, such as supported precompiles, gas costs for particular operations or opcode behaviour. Developers should test on the testnet instead of assuming identical behaviour.

What it does not guarantee. The zero-knowledge proof system proves that computation was done correctly. It does not prove that a dApp's code is safe, that an oracle price is accurate or that a team is trustworthy. Treat each protocol on the chain as its own risk decision.

For fee and speed expectations, check a block explorer for the network and the bridge page directly. Those figures move with demand and Ethereum data costs, so no single number in a guide stays accurate.

Before using any chain built on shared rollup tooling, verify that it is currently active. Layer-2 networks sometimes wind down, merge with other networks or change strategy, and these decisions are announced through official channels rather than being obvious from a wallet.

A short status checklist:

• Official documentation and blog. Look for notices about network status, deprecation, migration or sunset dates.
• Official social accounts. Confirm announcements on more than one official channel, and ignore replies or direct messages offering help.
• Block explorer. Check whether blocks are still being produced and whether recent activity looks normal.
• Bridge interface. Confirm that deposits and withdrawals are enabled and read any banner about deadlines.
• Polygon CDK and AggLayer notices. Changes to shared infrastructure may affect connected chains.
• dApp front ends. Check whether the protocols you plan to use still list the network.

If a chain is being wound down. The usual guidance is to withdraw assets to Ethereum well before any stated deadline, using the canonical bridge, and to close open positions in lending or liquidity protocols first. Withdrawals can take time, so leave margin. Do not wait for the final days.

This guide does not state the chain's current status because that can change. Treat the official sources above as the only authority, and treat any third-party page, including this one, as background rather than a status report.

Adding a network to a wallet is routine, but fake network details are a real attack path, so keep the process disciplined.

Step list

1. Open the official Astar documentation by typing the address yourself or using a bookmark you trust.
2. Find the network details page and copy the network name, RPC URL, chain ID, currency symbol and block explorer address.
3. In your wallet, choose to add a custom network and paste the values. Some wallets can add it automatically from a trusted listing; compare the details against the documentation.
4. Check that the currency symbol shows ETH if the docs say ETH is the gas token.
5. Switch to the network and confirm that the explorer link opens the correct explorer.

Getting funds onto the network

• Use a bridge supported by the official documentation. The canonical bridge is the lowest-trust option because it is part of the chain's own design.
• Third-party bridges and aggregators such as Across, LayerZero V2-based routes, Stargate V2 or Chainlink CCIP-based products only help if they list this specific chain, and that support can change. Verify before relying on them.
• Some centralized exchanges support direct withdrawals to certain layer-2 networks. If you use an exchange, check that the network is listed and selecting the wrong network can lose funds.

Always send a small test transaction first, then the larger amount once it arrives. Keep a little ETH for gas on the layer 2.

Moving assets between Ethereum and a zk layer 2 works in two directions with different timing.

Deposits (Ethereum to L2). You send tokens to the bridge contract on Ethereum. After enough confirmations on Ethereum, the bridge credits the balance on the layer 2. This usually takes minutes, but depends on Ethereum congestion and the bridge's own rules.

Withdrawals (L2 to Ethereum). With a canonical zk bridge, the withdrawal must be included in a batch, the batch must be proven, and the proof must be verified on Ethereum. After that you may need to claim the funds with a second transaction on Ethereum, which costs mainnet gas. Zk rollups can finalise faster than optimistic rollups, which use a long challenge period, but proving and settlement still add delay.

Fast exits. Third-party liquidity bridges and intent-based bridges can deliver funds sooner by fronting liquidity, charging a fee in return. They carry their own smart contract and liquidity risks and only work for supported chains and tokens.

Practical points:

• Token versions. Bridged tokens can be wrapped versions of the original asset. Check which version a dApp expects.
• Claim step. If funds appear to be missing after a withdrawal, check whether a claim transaction is still required.
• Compare other layer-2 bridges. Interfaces such as the Linea Bridge and Arbitrum Bridge illustrate how canonical bridges differ in timing and steps across networks.

Never approve unlimited token allowances to bridge contracts you have not verified, and revoke old approvals periodically.

A new layer 2 typically hosts the same categories of applications seen on Ethereum, though availability on any given chain varies and changes over time.

Common categories

• DEXs and aggregators for swapping tokens. Aggregators such as Matcha route across many exchanges, but only on the chains they support.
• Lending markets where you supply assets to earn interest or borrow against collateral. Protocols such as Aave V3 are examples of the model, but whether a protocol has deployed on this chain must be checked on its own site.
• Liquid staking and yield products that build on ETH.
• Gaming, NFT and consumer apps, which were a stated focus for Astar's ecosystem.

How to evaluate a dApp on a young chain

1. Confirm the contract addresses from the project's official documentation.
2. Look for audits and read the scope, not just the headline.
3. Check how much value is locked and how long the protocol has been live, using an independent analytics site, since figures change daily.
4. Review admin and upgrade permissions, and whether there is a timelock.
5. Understand where prices come from, since oracle weaknesses are a common cause of lending exploits.
6. Start with an amount you can afford to lose.

Liquidity on smaller chains can be thin, which increases slippage and can make exits harder during stress. Fewer users also means fewer people checking contracts for problems. Position size should reflect that.

Zero-knowledge proofs improve how a layer 2 proves correct execution, but users face several separate risks.

Chain-level risks

• Sequencer centralisation. One operator may control ordering and could halt the chain. Check whether there is a forced-inclusion route through Ethereum.
• Upgradeable contracts. Admin keys may be able to change the bridge or verifier. Look for timelocks and multisig details in documentation.
• Data availability. If the chain is configured as a validium, funds depend partly on an off-chain data committee.
• Young proving systems. Zk circuits are complex software and can contain bugs.
• Strategic risk. The team or its ecosystem partners may shift focus, which can lead to migrations or shutdowns.

User-level risks

• Phishing and fake bridges. Scammers copy bridge sites and network settings. Bookmark official pages.
• Unlimited approvals. Review and revoke token approvals with a reputable approval checker.
• Fake tokens. Anyone can deploy a token with a familiar name. Verify addresses.
• Seed phrase exposure. No bridge, support agent or airdrop claim page needs your recovery phrase.

For larger balances, use a hardware wallet, keep a separate wallet for experimenting with new dApps, and avoid leaving funds on any layer 2 longer than you need to. None of this is financial advice, and crypto assets can lose all their value.

If the network is winding down, or you simply want a layer 2 with more activity, several alternatives exist. Ecosystem sizes and incentives change often, so check current data before choosing.

Option	Technology	Why readers consider it
Astar Network (Polkadot)	Parachain with EVM and WASM	The original Astar chain with ASTR and dApp staking
Soneium	OP Stack-based Ethereum L2	Linked publicly to Astar's team and Sony Block Solutions Labs
Polygon chains	Polygon CDK and the wider Polygon ecosystem	Same tooling family as Astar zkEVM
Linea	zk rollup	Established zkEVM with an official bridge
Arbitrum	Optimistic rollup	Large DeFi ecosystem and a canonical bridge

How to choose

• Pick the network where the dApps you actually use are deployed.
• Compare bridge options and withdrawal times, including fast exit routes.
• Check whether your preferred exchange supports direct deposits and withdrawals to that network.
• Consider infrastructure: RPC providers such as Ankr offer endpoints for many networks, which can help if a default public RPC is unreliable.

A migration checklist

1. Close or unwind positions on the old chain, including lending, farming and staking.
2. Withdraw to Ethereum or to your destination chain through a supported route.
3. Verify arrival on a block explorer.
4. Revoke old token approvals.
5. Record transactions for tax purposes, since bridging and swapping can create reportable events in many jurisdictions.

If you are comparing chains, treat official documentation as the authority for status, and use independent dashboards for activity data.