X Layer Chain Overview: zkEVM Validium L2 by OKX
X Layer is OKX's exchange-backed Ethereum L2, launched April 15, 2024 as a zkEVM validium built on Polygon CDK. It pairs zk-validity-proof settlement with off-chain data availability for sub-cent gas, runs 2-second blocks, and uses OKB — not ETH — as its native gas token. Current TVL sits at $73.95M, with PotatoSwap V2 dominating on-chain liquidity. The August 2025 Pessimistic Proof upgrade targets ~5,000 TPS and unlocks AggLayer interoperability across Polygon CDK chains.
If you are evaluating where to deploy contracts, route non-custodial cross-chain swap liquidity, or simply understand which exchange-backed L2 fits your trust model, X Layer offers a specific, opinionated answer. It is zk-based, not optimistic — so you get zk-proof finality on a prover-batched cadence rather than 7-day optimistic challenge windows, but you also accept a data availability committee rather than Ethereum-grade calldata DA. It is full bytecode-equivalent EVM via Polygon CDK, meaning any Solidity contract compiled for Ethereum mainnet deploys here unchanged, and developer tooling (Hardhat, Foundry, MetaMask, WalletConnect) works out of the box. The unconventional choice — and the one most relevant when comparing to Base, Arbitrum, Optimism, or Scroll — is OKB as the gas token, which structurally ties chain economics to OKX's exchange flywheel rather than to ETH. For builders targeting OKX's large global user base, this is a feature; for protocol teams that want maximum L2 neutrality, it is a real consideration. X Layer's $73.95M TVL is modest versus Base ($3.84B) or Arbitrum ($1.24B), but among bytecode-equivalent zkEVM L2s it leads on TVL, ahead of Scroll and Abstract, while offering higher typical throughput than either. The chain has no publicly disclosed major exploit history, and its 2025-08 PP upgrade signals continued investment in throughput and AggLayer interop.
About X Layer
X Layer is an Ethereum Layer 2 launched by OKX on April 15, 2024, built on the Polygon Chain Development Kit (CDK) and operating as a zkEVM validium. The chain inherits Ethereum's Proof-of-Stake security through validity proofs while keeping transaction data off-chain in a data availability committee — the defining trade-off that distinguishes a validium from a pure rollup. This design choice prioritizes cheaper gas and higher throughput over the strict on-chain data guarantees of full rollups like Scroll or Linea, and reflects OKX's bet that exchange-anchored users will accept the DA assumption in exchange for sub-cent fees.
Unlike nearly every other major Ethereum L2, X Layer does not use ETH as its gas token. It uses OKB, the native exchange token of OKX, which ties the chain's economic activity directly to the OKX ecosystem and creates a sink for OKB demand. This is a deliberate architectural and political statement: X Layer is not a neutral public good in the way Optimism or Base aspire to be, but a vertically integrated extension of an exchange-led product stack, including OKX Wallet, OKX Web3, and the broader OKX trading infrastructure.
Technically X Layer is bytecode-equivalent zkEVM via Polygon CDK, meaning any Solidity contract that compiles for Ethereum mainnet can deploy here without changes. The validator set, sequencer, and prover are currently centralized under OKX-operated infrastructure, with a roadmap toward AggLayer integration that would allow X Layer to share liquidity and unified proofs with other Polygon CDK chains. This positions X Layer not as an isolated L2 but as a future node in Polygon's multi-chain settlement fabric.
The economic design centers on attracting OKX's existing user base into an on-chain venue with familiar UX, fiat onramps, and integrated CEX-to-DEX flows. TVL stands at $73.95M as of mid-2026, modest compared to Base ($3.84B) or Arbitrum ($1.24B), reflecting both the chain's youth (under two years old) and the fact that ecosystem traction has concentrated in a small number of native DEX protocols rather than imported DeFi blue chips.
X Layer technical parameters
X Layer is a zkEVM validium implemented with Polygon CDK, which means every batch of L2 transactions produces a zero-knowledge validity proof that is verified on Ethereum L1, while the underlying transaction data is held off-chain by a data availability committee rather than posted to Ethereum as calldata or blobs. The chain runs 2-second blocks, processes around 100 transactions per second in typical operation, and was architected with a theoretical ceiling of 5,000 TPS that the August 2025 Pessimistic Proof upgrade explicitly targets. Native gas is paid in OKB, the OKX exchange token — a design choice that makes X Layer the only major EVM L2 not denominated in ETH.
| Consensus | zkEVM validium (Polygon CDK) inheriting Ethereum PoS |
|---|---|
| VM | zkEVM (Polygon CDK) |
| Block time | 2 s |
| Finality | — |
| TPS | 100 typical / 5k max |
| Gas token | OKB |
| Launched | 2024-04-15 |
| Token standard | ERC-20 / ERC-721 / ERC-1155 |
| Address | hex (0x-prefixed, EVM) |
Consensus mechanism
X Layer does not produce its own L1-style consensus. Instead it inherits Ethereum's Proof-of-Stake security through cryptographic validity proofs. Here is how that works in plain language: the X Layer sequencer (currently operated by OKX) collects transactions from users, executes them in a zkEVM environment, and produces a state transition. A zk-prover then generates a succinct proof — typically a SNARK derived from the Polygon CDK proof stack — that mathematically attests the transition was computed correctly. That proof is posted to a verifier contract on Ethereum mainnet, which checks it in a single transaction. Once Ethereum L1 accepts the proof, the X Layer state at that point is final at Ethereum-grade security. The validium twist is that the raw transaction data backing each batch is not stored on Ethereum — it lives with a data availability committee, which is cheaper but introduces a separate trust assumption: if the committee colludes to withhold data, X Layer users cannot independently reconstruct their state from L1 alone. This is the central trade-off that differentiates X Layer from full zk-rollups like Scroll or Linea, which pay higher DA costs in exchange for stricter on-chain data guarantees.
Performance context
On paper, X Layer's 100 TPS typical sits above most optimistic L2s — Arbitrum runs around 40 TPS in typical conditions, Optimism around 30, Polygon PoS around 60, and Scroll around 30. The 5,000 TPS theoretical max, targeted by the Pessimistic Proof upgrade, is in the same league as Avalanche's 4,500 and BSC's 3,252 ceilings, though no major EVM L2 has yet demonstrated sustained five-figure TPS under real load. In practice X Layer's throughput is gated less by the prover or sequencer and more by ecosystem demand: the chain's $73.95M TVL produces nowhere near the transaction pressure that would stress its theoretical ceiling. The 2-second block time gives users near-instant soft confirmations, which matters far more for UX than the headline TPS number — and on that axis X Layer is competitive with every modern EVM L2.
X Layer ecosystem map
X Layer's ecosystem is small but visibly concentrated. With $73.95M in total TVL, the dominant theme is native DEX activity rather than imported lending or restaking primitives. PotatoSwap V2 alone holds $3.89M — over 5% of the entire chain TVL — making it the de facto liquidity hub. The protocol mix skews heavily toward AMM-style DEXes, with no significant lending market or perp DEX yet measured by DefiLlama, signaling that the ecosystem is still in an early liquidity-bootstrap phase.
DEX
PotatoSwap V2 is the largest protocol on X Layer with $3.89M TVL, operating as a standard Uniswap V2-style AMM. PotatoSwap V3 ($138K) adds concentrated liquidity. Together they anchor most of the chain's swap volume.
DEX
InSwap ($137K TVL) and DFS V2 ($75K) round out the secondary DEX layer. OkieSwap runs three deployments — V2, V3, and a stableswap variant — collectively holding around $128K, targeting low-slippage stable pairs.
Bridge
AggLayer is the headline bridging story: as a Polygon CDK chain, X Layer is positioned to share unified liquidity with other CDK chains via Polygon's interop layer, reducing the need for traditional lock-mint bridges between CDK ecosystems.
Wallet
OKX Wallet is the native wallet experience, with direct integration into OKX's centralized exchange for CEX-to-on-chain transfers. MetaMask, WalletConnect, and Rabby work without modification given X Layer's full EVM equivalence.
Infrastructure
The official RPC at rpc.xlayer.tech is operated by OKX; third-party RPC providers (Ankr, BlockPI, public node services) supplement availability. The block explorer at okx.com/web3/explorer/xlayer is the canonical chain browser.
| # | Protocol | Category | TVL |
|---|---|---|---|
| 1 | PotatoSwap V2 | Dexs | $3.89M |
| 2 | PotatoSwap V3 | Dexs | $138.13K |
| 3 | InSwap | Dexs | $137.51K |
| 4 | OkieSwap V3 | Dexs | $90.82K |
| 5 | DFS V2 | Dexs | $75.33K |
| 6 | Revoswap | Dexs | $35.20K |
| 7 | OkieSwap V2 | Dexs | $23.20K |
| 8 | OkieSwap Stableswap | Dexs | $13.98K |
X Layer vs peers
Within the EVM L2 category, X Layer sits in an unusual position: it shares the zk-validity-proof lineage with Scroll, Starknet, and Abstract, but uses Polygon CDK rather than its own proof system; it shares the exchange-backed go-to-market with Base, but uses zkEVM rather than OP Stack; and it is the only major EVM L2 that uses a non-ETH gas token (OKB). These choices produce measurably different positioning across TVL, throughput, and ecosystem maturity.
| Chain | Block | Finality | TPS | TVL |
|---|---|---|---|---|
| Arbitrum | 250 ms | 168 h | 40 | $1.24B |
| Optimism | 2 s | 168 h | 30 | $0.00 |
| Base | 2 s | 13 min | 1.5k | $3.84B |
| Polygon | 2 s | 5 s | 60 | $1.05B |
| Starknet | 2.5 s | 1.5 h | 3 | $184.41M |
| X Layercurrent | 2 s | — | 100 | $73.95M |
| Scroll | 3 s | 1 h | 30 | $10.79M |
| Abstract | 1 s | — | — | $11.13M |
Comparison insights
- TVL ranking: X Layer's $73.95M places it fifth among major EVM L2s tracked here — below Base ($3.84B), Arbitrum ($1.24B), Polygon ($1.05B), and Starknet ($184M), but ahead of Abstract ($11.1M) and Scroll ($10.8M). Among bytecode-equivalent zkEVM L2s specifically (excluding Starknet's Cairo VM), X Layer leads on TVL.
- Throughput: X Layer's 100 TPS typical and 5,000 TPS theoretical max (post-PP upgrade) outpaces Arbitrum (40 typical), Optimism (30), Polygon (60), and Scroll (30) in typical throughput, but lags Base's 1,500 TPS typical — the gap reflects Base's much larger live user load, not a hard technical ceiling.
- Block time: X Layer's 2-second blocks match Optimism, Base, and Polygon, are slower than Arbitrum's 0.25s and Abstract's 1s, but faster than Scroll's 3s and Starknet's 2.5s. The validium design lets X Layer keep blocks short without paying full DA costs to Ethereum.
- Gas token uniqueness: among the eight EVM L2s tracked here (Arbitrum, Optimism, Base, Polygon, Starknet, X Layer, Scroll, Abstract), X Layer is the only one that does not use ETH as the primary gas token — OKB takes that role. Polygon uses POL for staking but ETH for many DeFi flows; X Layer is structurally different.
- Decentralization stage: X Layer, like nearly all current EVM L2s, runs a centralized sequencer. Where Arbitrum and Optimism have published roadmaps and partial implementations of permissionless validation (BoLD, Cannon fault proofs), X Layer's decentralization path is tied to AggLayer's shared prover model, which is still in active development across the Polygon CDK ecosystem.
X Layer timeline
X Layer launched mainnet on April 15, 2024, after an extended testnet phase running on Polygon CDK infrastructure. The launch positioned OKX as the second major centralized exchange after Coinbase (Base, August 2023) to ship its own Ethereum L2, but with a distinctly different technology choice: where Base used the optimistic OP Stack, X Layer chose the zkEVM validium path via Polygon CDK, prioritizing ZK-based finality and lower DA costs over the more battle-tested OP Stack lineage. Early-2024 ecosystem activity was bootstrapped through OKX-led incentive campaigns and a wave of fork DEXes — PotatoSwap, OkieSwap, InSwap — that captured most of the early liquidity. The chain has not experienced any publicly disclosed major hack, exploit, or extended outage in its operational history, a clean record that distinguishes it from older L2s and L1s that have weathered bridge exploits or prolonged downtime. On August 1, 2025, X Layer shipped the Pessimistic Proof (PP) upgrade, a Polygon CDK-wide cryptographic primitive that bounds cross-chain message risk and unlocks AggLayer interoperability; OKX publicly targeted ~5,000 TPS theoretical throughput with this upgrade. Through 2025 and into 2026, X Layer has positioned itself less as a standalone L2 competing for DeFi blue chips and more as the OKX-flavored endpoint within an emerging Polygon CDK multi-chain mesh, betting that AggLayer interop will eventually let it share liquidity with other CDK chains without traditional bridging risk.
- 2024-04-15launchX Layer mainnet launch
- 2025-08-01upgradePP (Pessimistic Proof) upgrade — ~5,000 TPS target
Developer reference
X Layer exposes a standard JSON-RPC endpoint at https://rpc.xlayer.tech and uses 0x-prefixed hex addresses identical to Ethereum mainnet, making integration trivial for any team already shipping EVM code. The primary block explorer lives at okx.com/web3/explorer/xlayer, and full developer documentation is at https://web3.okx.com/xlayer/docs. Smart contracts are written in Solidity (or any EVM-targeting language: Vyper, Huff, Yul) and deployed via Hardhat, Foundry, or Remix without any chain-specific modifications — Polygon CDK preserves opcode-level EVM equivalence. Token standards follow ERC-20, ERC-721, and ERC-1155. Wallet support covers OKX Wallet (native), MetaMask, WalletConnect, and Rabby, so dApps can rely on the standard EIP-1193 provider interface. Gas is paid in OKB rather than ETH — a critical detail when porting fee logic from other L2s. There is no native account abstraction enforcement, but ERC-4337 bundlers can be deployed independently.
Assets swappable on X Layer
Grouped by category. Click any asset to open its swap page for a live quote.
DeFi assets
1 assets
X Layer settle-time comparison
Shorter bars mean faster confirmations. Real settle time also depends on network congestion — figures are indicative.
X Layer asset coverage comparison
Longer bars mean more assets are swappable on that chain.
Popular swap routes involving X Layer
Routes below reflect actual user preference. Click to jump straight to the swap page.
X Layer FAQ
01Is X Layer decentralized?
Not yet. As of mid-2026 the sequencer, validator set, and zk-prover are all operated by OKX. X Layer inherits Ethereum's settlement security through validity proofs, but liveness and ordering depend on OKX infrastructure. The roadmap includes decentralizing the sequencer and joining AggLayer's shared prover network, but no public timeline for permissionless sequencing has been confirmed.
02What is X Layer's finality time?
X Layer has a 2-second block time and produces blocks deterministically at the sequencer level, giving soft confirmation in seconds. Hard finality — the point at which a zk-proof is verified and settled on Ethereum L1 — is not publicly benchmarked as a fixed interval and depends on prover batching frequency. The 2025-08-01 Pessimistic Proof upgrade aims to push throughput toward 5,000 TPS while shortening proof cycles, but X Layer has not published an authoritative L1-settlement-time figure.
03Why does X Layer use OKB for gas instead of ETH?
Because X Layer is vertically integrated with OKX. Using OKB as gas creates a direct on-chain sink for the exchange's native token, ties chain activity to OKB demand, and aligns incentives between OKX, OKB holders, and X Layer users. The trade-off is friction: developers and users porting from other L2s must hold OKB rather than ETH to pay fees, which is unusual in the EVM L2 landscape.
04What is a zkEVM validium and how does it differ from a rollup?
A validium uses zero-knowledge proofs to verify state transitions on Ethereum L1, exactly like a zk-rollup, but stores transaction data off-chain with a data availability committee rather than posting it as calldata or blobs to Ethereum. This makes fees dramatically lower but introduces a DA trust assumption: if the committee withholds data, users may not be able to reconstruct their state independently. Scroll and Linea are full zk-rollups; X Layer is a validium.
05How does X Layer's TVL compare to other EVM L2s?
Modest. X Layer's $73.95M TVL sits well below Base ($3.84B), Arbitrum ($1.24B), and Polygon ($1.05B), and trails Starknet ($184M), but stands ahead of Abstract ($11.1M) and Scroll ($10.8M). Within the EVM L2 category it occupies a mid-tier position — small enough that liquidity is concentrated in a few DEXes (PotatoSwap dominates), but large enough to sustain real on-chain activity rather than being purely speculative.