eth_getBlockByNumber

Returns block information by number. On Flashblocks endpoints, the pending tag returns the live pre-confirmed block updated every ~200ms.

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 · string · required

Block number in hex, or "latest", "pending", "safe", "finalized", "earliest". Use "pending" on a Flashblocks endpoint to get the in-progress block.

fullTransactions · boolean · required

If true, returns full transaction objects. If false, returns only transaction hashes.

Returns

result · object

A block object, or null if no block was found.

Show Block fields

number · string

Block number in hex. null when pending.

hash · string

Block hash. null when pending.

parentHash · string

Hash of the parent block.

nonce · string

PoW nonce. Always "0x0000000000000000" on Base (PoS).

sha3Uncles · string

Hash of the uncles list. Always empty on Base.

logsBloom · string

Bloom filter for the block’s logs.

transactionsRoot · string

Root of the transaction trie.

stateRoot · string

Root of the final state trie.

receiptsRoot · string

Root of the receipts trie.

miner · string

Address of the fee recipient (coinbase).

difficulty · string

Always "0x0" on Base (PoS).

totalDifficulty · string

Always "0x0" on Base (PoS).

extraData · string

Arbitrary data field set by the sequencer.

size · string

Block size in bytes (hex).

gasLimit · string

Maximum gas allowed in this block (hex).

gasUsed · string

Total gas used in this block (hex).

timestamp · string

Unix timestamp (hex).

transactions · array

Array of transaction hashes or full transaction objects.

uncles · array

Always [] on Base.

withdrawals · array

Always [] on Base.

baseFeePerGas · string

EIP-1559 base fee per gas (hex).

blobGasUsed · string

Total blob gas used (EIP-4844, hex).

excessBlobGas · string

Excess blob gas for blob fee calculation (EIP-4844, hex).

parentBeaconBlockRoot · string

Parent beacon block root (EIP-4788).

requestsHash · string

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
number	Sealed block number	Current block number (being built)
hash	Final block hash	Hash of the partial block at this Flashblock index
gasUsed	Final gas used	Cumulative gas used up to this Flashblock
transactions	All sealed transactions	Transactions pre-confirmed so far
blobGasUsed	Final blob gas used	Propagated from cumulative Flashblock state

Example

Standard (latest sealed block)

curl https://mainnet.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBlockByNumber",
    "params": ["latest", false],
    "id": 1
  }'