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Available on Testnet today (Whitechain Sepolia, chain ID 1874). Mainnet is not yet live; its chain ID, endpoints, and launch date are published before Mainnet launch. All forward-looking roadmap schedules, Mainnet launch dates, and specifications are subject to change without prior notice.

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General

Whitechain is an EVM-compatible Layer 2 built on the OP Stack, developed in alignment with the WhiteBIT ecosystem. It settles on Ethereum through blob data availability and uses WBT (WhiteBIT Coin) as the native gas token. At launch, a single sequencer node is run by a designated infrastructure operator under the standard OP Stack consensus configuration. Sequencer management operates independently of user dApps, and the protocol roadmap targets progressive transition to permissionless, decentralized sequencing. See Introduction to Whitechain.
The L2 is live on Testnet today, as Whitechain Sepolia (chain ID 1874). Mainnet is not yet live. Its chain ID, endpoints, and launch date are published before Mainnet launch. Build and test on Whitechain Sepolia now, then move to Mainnet at launch. See the Network reference.
The OP Stack separates execution, data availability, and settlement into distinct layers. Every transaction’s data is published and settled on Ethereum, so Whitechain inherits Ethereum’s security and data-durability guarantees instead of carrying its own. This technical design relies on underlying Ethereum mechanics; Whitechain provides no independent warranties regarding Ethereum network integrity. The chain keeps full EVM compatibility, so any contract or toolchain that works on Ethereum works on Whitechain. The OP Stack also underlies Base, Optimism, and the wider Superchain, which gives Whitechain shared tooling and a path toward decentralized sequencing.
Nothing is required from you. The legacy L1 is live and producing blocks today. At L2 Mainnet launch the full L1 state migrates into the L2 genesis automatically. Native WBT balances are preserved to the wei, and contracts keep their bytecode, storage, nonces, and addresses. ERC-20 and other token balances live in contract storage, so they migrate with it. Transaction history and pending mempool transactions are not carried over; only final state is. After the snapshot block the L1 answers read methods only, and it is decommissioned later, so export any historical data you need before then. Users and application operators are solely responsible for archiving historical L1 data prior to decommissioning; Whitechain assumes no liability for unexported data loss. See Migration to L2.
Holders have no deadline, because holders have no task to complete. There is nothing to claim, swap, or unlock. Integrations have milestones to plan against: the L1 snapshot block, L2 Mainnet launch, the domain cut-over, the L1 read-only period, and L1 decommissioning. No date for any of them is announced yet. Whitechain publishes migration dates on X, in the Whitechain Telegram channel, and on the migration page. See Deadlines.
Your users’ balances migrate on their own; your connection settings do not. Repoint to the L2 chain ID, RPC URL, and explorer, stop crediting L1 deposits at the snapshot block, and export any L1 history your systems need before decommissioning. Contracts need no redeployment.The hostnames also change. rpc.whitechain.io and explorer.whitechain.io serve the legacy L1 (chain ID 1875) today and serve the L2 after the cut-over. The L1 explorer moves to https://legacy-explorer.whitechain.io, the L1 website moves to https://legacy.whitechain.io, and the legacy read-only RPC hostname is published in the Network reference before Mainnet launch. Confirm which chain an endpoint serves with eth_chainId rather than by hostname. See Endpoint and domain changes and Integrations and service operators.
Blocks arrive every second, and that inclusion is the sequencer’s word only. Your transaction becomes safe when its batch is confirmed on Ethereum, up to about 30 minutes on Testnet, and finalized about 13 minutes after that. Only finalization is irreversible. See Transaction finality.
A designated infrastructure operator runs the single sequencer at launch strictly on an “AS IS” and “AS AVAILABLE” technical basis, without operational SLAs, uptime warranties, or liveness guarantees. Sequencer liveness does not compromise protocol security. In the event of sequencer downtime, latency, or transaction omission, the open-source OP Stack architecture allows users to bypass the sequencer and force transaction inclusion. That path runs directly through the L1 OptimismPortal smart contract on Ethereum. See What keeps your funds safe.
For WBT held on the exchange, use WhiteBIT support. For integration, node, or contract questions, use the Whitechain Discord. Migration dates are announced on X and in the Whitechain Telegram channel. Support never asks for your seed phrase, private key, or a wallet signature to complete a migration step. See Where to get help.

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Fees and WBT

You pay gas in WBT, the native gas token, configured as the OP Stack custom gas token with 18 decimals. Every fee on Whitechain is paid in WBT, regardless of network, so you need a WBT balance to send any transaction. WBT is the native asset of Whitechain and the token of the WhiteBIT ecosystem, so a single asset covers on-chain gas and exchange utility. See Network fees.
A fee has two parts: the L2 execution fee (gas used times the gas price) and the L1 data fee for publishing your transaction to Ethereum. At the 5 gwei base-fee floor, a plain WBT transfer of 21,000 gas costs about 0.000105 WBT to execute, well under one cent at $50 per WBT. Deploying a small contract costs about 0.0006 WBT, roughly three cents at that price. Cost calculations and token price references are purely illustrative and non-binding; actual transaction costs fluctuate based on dynamic L1 and L2 market conditions. The L1 data fee is added on top and tracks Ethereum’s gas price, so totals rise when Ethereum is busy. See Network fees.
Buy WBT on WhiteBIT, through the Convert tool or a fiat deposit, then withdraw it to your Whitechain address. You can also bridge ERC-20 WBT from Ethereum mainnet. After Mainnet launch, WhiteBIT users withdraw WBT directly to Whitechain L2 from the exchange UI, with no third-party bridge in between. Exchange purchases and withdrawals remain subject to WhiteBIT’s Terms of Use, legal restrictions, and KYC/AML verification. See Getting WBT.
Claim test WBT from the faucet at faucet.testnet.whitechain.io. Add Whitechain Sepolia to your wallet first, using chain ID 1874 and the RPC at https://rpc.testnet.whitechain.io/. Sign in with a GitHub account at least 30 days old. The standard drip is 0.5 WBT per 24-hour rolling window. Test WBT has no real value and cannot be bridged to mainnet. See Faucet.
The explorer may show only the L2 execution fee. The L1 data fee for publishing your transaction to Ethereum is charged on top of it, and the difference is that fee. Both parts are always charged. See Network fees.
Yes. The network does the work up to the point of failure, so you pay for the gas used, and both fee parts are charged. Nothing is refunded. Set a sufficient gas limit so a contract call does not run out partway through. See Network fees.
The L2 base fee follows EIP-1559 with elasticity 6 and denominator 100, so a full block raises it by 5%, an empty block lowers it by 1%, and it never drops below the 5 gwei base fee floor. The L1 data fee is the variable part: it tracks Ethereum’s base fee and blob base fee, so your total rises when Ethereum is busy. See Fee parameters.

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For developers

Yes. Whitechain keeps full EVM compatibility, so any contract or toolchain that runs on Ethereum runs on Whitechain without modification. Deploy with Hardhat, Foundry, Remix, or any Ethereum library. Developers are solely responsible for conducting independent security audits and verifying regulatory compliance of their deployed code. See Deploy a contract.
Whitechain Sepolia is live now; Mainnet parameters are published before Mainnet launch.Whitechain Sepolia also exposes a WebSocket endpoint at wss://rpc.testnet.whitechain.io/ws. See the Network reference.
Whitechain Sepolia is a standard EVM network, so you add it by chain ID and RPC URL and need no Whitechain-specific plugin. Deploy with your usual toolchain, then verify the source on the explorer or Sourcify. The Deploy with Hardhat guide covers the full deploy-and-verify flow; Remix and Foundry guides are also available.
Use Whitechain Sepolia (chain ID 1874), the public test environment for dapp deployment, integration testing, and claiming test WBT from the faucet. See Connect to Whitechain Sepolia.
Any standard EVM wallet. Whitechain documents MetaMask, Rabby, and Reown (formerly WalletConnect) for everyday signing, and Safe for multisig treasury and admin operations. No Whitechain-specific plugin exists, because you add the network by chain ID and RPC URL. Third-party wallets are external tools operated by independent entities; Whitechain disclaims all liability for their software security or operational failures. See Wallets.
No. Use the Ethereum libraries you already use. viem includes OP Stack support, so it returns the L1 data fee and keeps working across network upgrades without edits to your code. See Use viem with Whitechain.

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Public RPC and infrastructure

Yes, per client IP address. You get 50 requests per second, plus a burst allowance of 500 requests above that. When you exceed it, the endpoint returns HTTP 429 Too Many Requests with a Retry-After header. The limiter counts each HTTP request, so batching several calls into one request helps. See Public RPC endpoints.
No. The public RPC and WebSocket endpoints need no API key and no IP allowlist. Reads and writes are open to any client, subject to the limits above.
The endpoint returns HTTP 429 Too Many Requests with a Retry-After header. Retry with exponential backoff, starting from the Retry-After value. A client that retries immediately stays above the limit and keeps failing. Batch related calls into one JSON-RPC request, because the limiter counts one HTTP request per batch. Subscribe to newHeads over WebSocket instead of polling eth_blockNumber, and cache receipts and finalized blocks on your side. See Working within the limits.
Not yet. Whitechain is evaluating partnerships with commercial RPC providers, and partner endpoints are published in the Public RPC endpoints table when they go live. Until then, https://rpc.testnet.whitechain.io and wss://rpc.testnet.whitechain.io/ws are the only public endpoints for Whitechain Sepolia. Treat any other endpoint claiming to serve chain ID 1874 as unofficial.
Yes. Whitechain Sepolia exposes wss://rpc.testnet.whitechain.io/ws. It serves the standard Ethereum JSON-RPC API and supports eth_subscribe, including newHeads, logs, and newPendingTransactions. Reuse one connection for multiple subscriptions rather than opening a connection per query. See WebSocket and subscriptions.
No, and there is no stream to read yet: Flashblocks are not enabled on Whitechain Sepolia. When they are, the stream is separate from the public RPC, which does not carry it. See Flashblocks.
Run your own node. The stack is a pair of services, op-reth and op-node, and ships three profiles: full-snap-node (recommended default), full-node, and archive-node. Archive is the one required for historical tracing and eth_call at old blocks. Your node holds no Whitechain keys and forwards eth_sendRawTransaction to the public RPC. See Node operators.
Yes to both. Whitechain uses Blockscout, and its API is public, read-only, and needs no API key. It is rate limited per IP, so batch related lookups and cache results. For sustained querying across full chain history, run your own indexer or Blockscout instance. See Block explorer overview.
Check status.whitechain.io for the RPC, explorer, and faucet. A 429 response is a rate limit on your side, not an outage, and it clears once your request rate drops.

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Bridging and withdrawals

Use the OP Stack canonical bridge. Deposits from Ethereum to Whitechain arrive on L2 in about 2 minutes, following Ethereum block times. For an ERC-20 token, you approve the L1 standard bridge and call depositERC20; the L2 token must already be deployed. Native WBT cannot go through the canonical bridge, because Whitechain runs in custom gas token mode: use the faucet on testnet, and the liquidity portal on mainnet. You can also move WBT through WhiteBIT deposits and withdrawals. See the OP Stack canonical bridge.
On testnet a full withdrawal takes about an hour, because the dispute-resolution delays are intentionally shortened. Whitechain Mainnet is not live, so its figure is not published; on OP Mainnet the equivalent delay is a minimum of 7 days. Whichever network you are on, the dispute-resolution delay is enforced by the contracts and cannot be skipped, so plan treasury and time-sensitive flows accordingly. Deposits run the other way in about 2 minutes. Both figures move with L1 block times and congestion. See Transaction finality.
Whitechain runs in OP Stack custom gas token mode, where the native token is WBT instead of ETH. The canonical bridge does not carry the native gas token in that mode. Use the faucet on testnet, the liquidity portal on mainnet, or WhiteBIT deposits and withdrawals. ERC-20 tokens do go through the canonical bridge. See OP Stack canonical bridge.
No. The dispute window is enforced by the protocol on Ethereum, so no fee or support request shortens it. A withdrawal is proven and finalized in two steps, and it cannot be cancelled once proven. Plan treasury flows around the 7-day minimum on mainnet. See Transaction finality.
Subject to technical deployment upon Mainnet launch and applicable exchange terms, yes. WhiteBIT users are expected to have the option to withdraw WBT directly to Whitechain L2 from the exchange UI, with no third-party bridge in the path. New users land on Whitechain with WBT in their wallet through the exchange flow they already use. Direct withdrawal functionality remains subject to WhiteBIT’s Terms of Use, jurisdictional availability, and identity verification requirements. See Getting WBT.

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For projects

The Whitechain Foundation runs the Builders Program with financial, marketing, and technical support for projects building on Whitechain. Support is released against delivery milestones rather than as a lump sum. Projects that need more than the program covers are evaluated under the Investment Program, where terms are agreed per project. Participation in the Builders Program is discretionary, non-binding, and subject to separate legal contracts, KYC screening, and sanctions compliance. See the Whitechain Builders Program and For project partners.