state_getStorage

Description

Retrieves the storage value for a given key. The return value is SCALE-encoded and must be decoded with the appropriate type information from metadata.

Parameters

Parameter	Type	Required	Description
storageKey	string	Yes	Hex-encoded storage key
blockHash	string	No	Block hash to read historical data

Returns

Field	Type	Description
result	string | null	SCALE-encoded storage value or null if the key is absent

Request Example

{
  "jsonrpc": "2.0",
  "method": "state_getStorage",
  "params": [
    "0x26aa394eea5630e07c48ae0c9558cef7b6a7c9a35a95a160cb4cad330558dfa56d6f646c755b98a7afd0913860592153322b957be394a0619f20b32679ac1014"
  ],
  "id": 1
}

Response Example

{
  "jsonrpc": "2.0",
  "result": "0x0100000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000",
  "id": 1
}

Decoding this SCALE blob yields a System.Account record with nonce = 1 and free = 4_000_000_000_000 (0.004 BNC).

Code Examples

Python

account = substrate.query(
    module='System',
    storage_function='Account',
    params=['15mYsj6DpBno58jRoV5HCTiVPFBuWhDLdsWtq3LxwZrfaTEZ']
)
print(account.value['data']['free'])

JavaScript

const storageKey = api.query.system.account.key('15mYsj6DpBno58jRoV5HCTiVPFBuWhDLdsWtq3LxwZrfaTEZ');
const raw = await api.rpc.state.getStorage(storageKey);
const accountInfo = api.createType('FrameSystemAccountInfo', raw);
console.log(accountInfo.data.free.toHuman());

Tips

• Construct storage keys with helper functions (api.query.system.account.key in polkadot.js) to avoid hashing mistakes.
• When iterating large sets, use state_getKeysPaged to collect keys first, then fetch values in batches.
• Always decode using runtime metadata corresponding to the block hash you queried.