eth_blockNumber

eth_blockNumber returns the height of the most recently accepted block on the Avalanche C-Chain — the EVM contract chain where gas is paid in AVAX. Because the C-Chain runs the Snowman consensus protocol with roughly one-to-two-second finality, the value advances quickly, and an accepted block here is already final rather than merely the longest fork. Send the request to https://avalanche.therpc.io/YOUR_API_KEY (chain ID 43114) and you get back the current tip as a hex-encoded integer such as "0x2f1a4c".

Use cases

• Heartbeat or liveness probe — the cheapest call (1 CU) to confirm your Avalanche C-Chain endpoint is reachable and producing blocks.
• Establish the current C-Chain height before paginating eth_getLogs across a historical range.
• Drive a "wait for N confirmations" loop in Snowtrace-verifiable deployment scripts; on the C-Chain a couple of blocks already implies finality.
• Compare the tip against a target block number to decide whether a transaction has been accepted under Snowman consensus.

Parameters

Diese Methode erwartet keine Parameter. Übergib ein leeres Array [].

Response

Example request

1curl https://avalanche.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 Avalanche playground.

Errors & troubleshooting

Common pitfalls

• The result is a hex string like "0x2f1a4c", not a number — parse it with parseInt(value, 16) or BigInt(value) before doing any arithmetic.
• Providers cache this value aggressively; two calls milliseconds apart can return the same height even though, at ~1–2s block times, the C-Chain advances often.
• This is the Avalanche C-Chain (an EVM chain on its own subnet), not an L2 rollup — the number is the native C-Chain height, with no separate L1 batch number to reconcile.

Supported networks

• Mainnet — Chain ID: 43114
• Fuji

See also

• eth_getBlockByNumber
• eth_getBlockByHash
• eth_syncing
• eth_chainId

1curl https://avalanche.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":[]}'