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Storage Subquery

Description​

Storage subqueries provide the value in a contract's storage slot at some past block. A very useful tool for looking up storage slots for contract addresses is evm.storage. See also Finding Storage Slots.

Limits​

Maximum of 128 storage subqueries.

Usage​

To access data about the storage of an Ethereum account with address address at the block number blockNumber, you must first construct a Storage object using the getStorage function:

const getStorage: (
  blockNumber: number | CircuitValue,
  address: string | CircuitValue
) => Readonly<Storage>;

The returned Storage is an interface with the functions below. Note that all functions in the interface are async.

Example Usage​

Here is an example of how to use the Storage interface:

const storage: Storage = getStorage(blockNumber, address);
const slotValue: CircuitValue256 = storage.slot(slot);

Storage Interface​

slot: (slot: ConstantValue | CircuitValue256 | CircuitValue) =>
  Promise<CircuitValue256>;

Returns the uint256 value stored in the storage slot slot. Returns 0 if the slot is empty (including if the account is an EOA or the account does not exist).