Returns information about a block by its number.
Flashblocks: Query https://mainnet-preconf.base.org with "pending" to fetch the live Flashblock in progress — a real block object updated every ~200ms with new pre-confirmed transactions. The response shape is identical; the block is simply not yet sealed.
Parameters Block number in hex, or "latest", "pending", "safe", "finalized", "earliest". Use "pending" on a Flashblocks endpoint to get the in-progress block.
If true, returns full transaction objects. If false, returns only transaction hashes.
Returns A block object, or null if no block was found. Block number in hex. null when pending.
Block hash. null when pending.
Hash of the parent block.
PoW nonce. Always "0x0000000000000000" on Base (PoS).
Hash of the uncles list. Always empty on Base.
Bloom filter for the block’s logs.
Root of the transaction trie.
Root of the final state trie.
Root of the receipts trie.
Address of the fee recipient (coinbase).
Always "0x0" on Base (PoS).
Always "0x0" on Base (PoS).
Arbitrary data field set by the sequencer.
Block size in bytes (hex).
Maximum gas allowed in this block (hex).
Total gas used in this block (hex).
Array of transaction hashes or full transaction objects.
EIP-1559 base fee per gas (hex).
Total blob gas used (EIP-4844, hex).
Excess blob gas for blob fee calculation (EIP-4844, hex).
Parent beacon block root (EIP-4788).
Hash of requests (EIP-7685).
Flashblock-Specific Response Fields When querying "pending" on a Flashblocks endpoint, the response is a live snapshot of the block being built. A few fields behave differently:
Field Standard latest Flashblocks pending numberSealed block number Current block number (being built) hashFinal block hash Hash of the partial block at this Flashblock index gasUsedFinal gas used Cumulative gas used up to this Flashblock transactionsAll sealed transactions Transactions pre-confirmed so far blobGasUsedFinal blob gas used Propagated from cumulative Flashblock state
Example Standard (latest sealed block)
Flashblocks (pending, live at ~200ms)
Response
curl https://mainnet.base.org \ -X POST \ -H "Content-Type: application/json" \ -d '{ "jsonrpc": "2.0", "method": "eth_getBlockByNumber", "params": ["latest", false], "id": 1 }'
