eth_getTransactionCount

Returns the number of transactions sent from an address. The value is the account nonce — pass it as nonce when constructing the next transaction.

On a Flashblocks endpoint (https://mainnet-preconf.base.org), querying with "pending" returns the nonce inclusive of every pre-confirmed transaction and refreshes every ~200ms. This eliminates nonce gaps when an agent submits transactions at high frequency.

Parameters

Name	Type	Required	Description
address	string	Yes	The 20-byte address to query.
block	string	Yes	A block number in hex, or one of "latest", "pending", "safe", "finalized", "earliest". Use "pending" against a Flashblocks endpoint to include all pre-confirmed transactions in the count.

Returns

Field	Type	Description
result	string	The transaction count (nonce) as a hexadecimal string.

Example

Request (standard, latest confirmed)

curl https://mainnet.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionCount",
    "params": ["0x742d35Cc6634C0532925a3b8D4C9dD0b4f3BaEa", "latest"],
    "id": 1
  }'

Request (Flashblocks pending nonce, ~200ms)

curl https://mainnet-preconf.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionCount",
    "params": ["0x742d35Cc6634C0532925a3b8D4C9dD0b4f3BaEa", "pending"],
    "id": 1
  }'

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x4d2"
}