eth_blockNumber

eth_blockNumber returns the height of the most recently accepted block on Base — the OP Stack rollup built by Coinbase, where ETH is the gas token and the sequencer produces a new block roughly every 2 seconds. Point it at https://base.therpc.io/YOUR_API_KEY (chain ID 8453) and it answers with the current L2 tip as a hex integer, with no parameters required. It is the lightest call in the JSON-RPC surface, which makes it the natural first ping when you want to know how far Base has advanced.

Use cases

• Heartbeat or liveness probe — the cheapest call (1 CU) to confirm your Base endpoint is up and the sequencer is producing blocks.
• Establish the current L2 height before paginating historical eth_getLogs ranges so you never request blocks past the tip.
• Drive a "wait for N confirmations" loop in Base deployment scripts, polling every couple of seconds to match the ~2s block cadence.
• Compare the returned height against a target block to judge how close a transaction is to finalizing on Ethereum L1.

Parameters

Este método no acepta parámetros. Pasa un array vacío [].

Response

Example request

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_blockNumber",
7    "params": [],
8    "id": 1
9  }'

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• The result is a hex string like "0xabc123", not a number — run it through parseInt(value, 16) or BigInt(value) before any arithmetic.
• Providers cache the tip aggressively; two calls milliseconds apart can return the same value even though Base blocks land about every 2 seconds.
• This is the Base L2 block height, not the Ethereum L1 batch number where the rollup settles — don't mix the two when reasoning about finality.

Supported networks

• Mainnet — Chain ID: 8453
• Sepolia — Chain ID: 84532

See also

• eth_getBlockByNumber
• eth_getBlockByHash
• eth_syncing
• eth_chainId

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'