> ## Documentation Index
> Fetch the complete documentation index at: https://l2docs.whitechain.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Whitechain Sepolia (testnet)

> Network reference for the Whitechain Sepolia testnet: how to connect, public RPC limits, fees, and withdrawal timing.

## At a glance

| Parameter     | Value                            |
| ------------- | -------------------------------- |
| Network name  | Whitechain Sepolia               |
| Short name    | WCH Sepolia                      |
| Chain ID      | `1874` (hex `0x752`)             |
| L1            | Ethereum Sepolia (`11155111`)    |
| Gas token     | WBT (WhiteBIT Coin, 18 decimals) |
| L2 block time | 1s                               |
| Flashblocks   | Enabled, about every 200 ms      |

Flashblocks are preconfirmations the sequencer streams ahead of each full one-second L2 block. They carry the sequencer's word only, and they do not change when a transaction becomes safe or finalized. See [Flashblocks in Transaction finality](/learn/network/transaction-finality#flashblocks) for the mechanism and how the four confirmation stages differ.

## Endpoints

| Type       | URL                                                                      |
| ---------- | ------------------------------------------------------------------------ |
| Public RPC | `https://rpc.testnet.whitechain.io`                                      |
| WebSocket  | `wss://rpc.testnet.whitechain.io/ws`                                     |
| Explorer   | [explorer.testnet.whitechain.io](https://explorer.testnet.whitechain.io) |
| Faucet     | [faucet.testnet.whitechain.io](https://faucet.testnet.whitechain.io)     |

To check current uptime for these endpoints, see the [status page](https://status.whitechain.io/).

## Public RPC rate limits

The public RPC is rate limited per client IP address. When you exceed the limit, the endpoint returns `429 Too Many Requests` with a `Retry-After` header.

| Property                         | Value                                                    |
| -------------------------------- | -------------------------------------------------------- |
| Sustained rate                   | 50 requests per second per client IP                     |
| Burst allowance                  | Up to 500 requests above the sustained rate              |
| What the limit counts            | Each HTTP request, not each JSON-RPC call inside a batch |
| Status code when you are limited | `429 Too Many Requests`                                  |
| Retry hint                       | `Retry-After: 1` header on every `429` response          |
| WebSocket limits                 | Published once they are finalized                        |

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. No third-party public endpoint serves Whitechain Sepolia yet. For the full list of public endpoints across networks, including planned third-party endpoints, and for guidance on handling `429` responses, see [Public RPC endpoints](/learn/network/reference#public-rpc-endpoints).

## WebSocket and subscriptions

The node exposes a WebSocket endpoint at `wss://rpc.testnet.whitechain.io/ws`. It serves the standard Ethereum JSON-RPC API and supports `eth_subscribe` for real-time updates, including `newHeads`, `logs`, and `newPendingTransactions`. Reuse one connection for multiple subscriptions rather than opening a connection per query. See [Public RPC rate limits](#public-rpc-rate-limits) for the limits that apply.

## Fees

Whitechain uses EIP-1559 with a 1-second block time, so fees stay low and predictable.

<Accordion title="All fee parameters">
  | Parameter             | Value                                              |
  | --------------------- | -------------------------------------------------- |
  | `baseFeeScalar`       | 100000                                             |
  | `blobBaseFeeScalar`   | 1000000                                            |
  | `operatorFeeScalar`   | 0                                                  |
  | `operatorFeeConstant` | 0                                                  |
  | `gasLimit`            | 40000000                                           |
  | `minimumGasLimit`     | 21000000                                           |
  | `maximumGasLimit`     | 500000000                                          |
  | `eip1559Elasticity`   | 6                                                  |
  | `eip1559Denominator`  | 250 (100 at genesis, 250 since the Canyon upgrade) |
  | `minBaseFee`          | 5000000000                                         |
</Accordion>

## Withdrawals

L2 withdrawals finalize after the dispute window ends. On testnet the dispute delays total 20 minutes, but a full withdrawal takes about an hour, and up to three hours in the worst case. A withdrawal can only be proven against a dispute game that covers its L2 block, and the proposer publishes a new game every 30 minutes. On mainnet a withdrawal takes at least 7 days. See [OP Stack canonical bridge](/build/bridge/bridge-assets#timing-parameters) for the full breakdown.

<Accordion title="Dispute game parameters">
  | Parameter                         | Value (seconds) |
  | --------------------------------- | --------------- |
  | `proofMaturityDelaySeconds`       | 900             |
  | `disputeGameFinalityDelaySeconds` | 300             |
  | `faultGameWithdrawalDelay`        | 600             |
  | `faultGameClockExtension`         | 300             |
  | `faultGameMaxClockDuration`       | 900             |
  | `preimageOracleChallengePeriod`   | 300             |
</Accordion>

## Related

* [Connect to Whitechain Sepolia](/learn/get-started/connect-wallet)
* [Deploy a contract](/learn/get-started/deploy-a-contract)
* [Next dapp template](/build/dapps/dapp-with-nextjs)
* [Transaction finality](/learn/network/transaction-finality)
* [Service status](https://status.whitechain.io/)