RPC endpoints and chain IDs
| L2 mainnet | Whitechain Sepolia | Legacy L1 mainnet | Legacy L1 testnet | |
| RPC | https://rpc.whitechain.io/ | https://rpc.testnet.whitechain.io | https://legacy.rpc.whitechain.io | https://rpc-testnet.whitechain.io |
| Chain ID | 1875 (0x753) | 1874 (0x752) | 1875 (0x753) | 2625 (0xa41) |
| Explorer | https://explorer.whitechain.io/ | https://explorer.testnet.whitechain.io/ | https://legacy.explorer.whitechain.io/ | https://testnet.whitechain.io/ |
On the public HTTPS endpoint https://rpc.testnet.whitechain.io, the limit is 50 requests per second sustained per client IP, plus a burst allowance of up to 500 requests above that.
When you exceed it, the endpoint returns HTTP 429 Too Many Requests with a Retry-After: 1 header. The limiter counts each HTTP request, so batching several JSON-RPC calls into one request helps. WebSocket rate limits are published once they are finalized, and Mainnet limits are published before Mainnet launch.
What should my client do when it hits the rate limit?
In this case, retry with exponential backoff, starting from the Retry-After value; a client that retries immediately keeps failing.
Batch related calls into one JSON-RPC request. Subscribe to newHeads over WebSocket instead of polling eth_blockNumber, and cache receipts and finalized blocks on your side.
FAQ
How to identify whether an endpoint is down or the request is rate-limited?
You can check https://status.whitechain.io for the RPC, explorer, and faucet. It monitors Testnet components only today; Mainnet monitoring is added at launch.
Do I need an API key for the public RPC?
No. The public RPC and WebSocket endpoints need no API key and no IP allowlist.
Is there a WebSocket endpoint?
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. Recommended using one connection for multiple subscriptions rather than opening one per query.
Are there third-party public RPC endpoints?
Not yet. Whitechain is evaluating partnerships with commercial RPC providers, and partner endpoints are published in the Network reference when they go live. Until then, https://rpc.testnet.whitechain.io and its WebSocket are the only public endpoints for Whitechain Sepolia. Please treat any other endpoint claiming to serve chain ID 1874 as unofficial.
Is the block explorer API public?
Yes. Whitechain uses Blockscout, and its API is public, read-only, and needs no API key. It exposes REST, Ethereum RPC, Etherscan-compatible RPC, and GraphQL interfaces, with an API reference at explorer.testnet.whitechain.io/api-docs. It is rate-limited per IP, so batch related lookups and cache results. You can run your own indexer or Blockscout instance for sustained querying across full chain history.