debug_storageRangeAt

eth_getStorageAt reads one slot at a block boundary. debug_storageRangeAt goes much deeper: it walks a contract's storage slots in pages, starting from a key hash you supply and returning up to your requested limit, captured at the state that exists immediately after a specific transaction inside a block. On BNB Smart Chain (BSC), where BEP-20 contracts power apps such as Venus and PancakeSwap and gas is paid in BNB, that mid-block snapshot is exactly what an incident review needs. Issue the call against chain ID 56 at https://bsc.therpc.io/YOUR_API_KEY. The method rebuilds historical state, which is heavy work, so it leans on a debug-enabled archive node.

Use cases

Dump the full storage layout of a BEP-20 token or vault contract at one precise execution point for an incident post-mortem.
Check that slot assignments in an upgradeable proxy line up with the layout the implementation contract expects.
Diff a contract's storage just before and just after a suspicious transaction to see which slots the attacker touched.

Parameters

#	Name	Type	Required	Description
1	`blockHash`	string	Yes	Hash of the block containing the transaction of interest.
2	`txIndex`	integer	Yes	Index of the transaction within the block after whose execution the storage is read.
3	`contractAddress`	string	Yes	Address of the contract whose storage to inspect.
4	`startKey`	string	Yes	Storage key hash from which to begin iteration. Use `0x0000…0000` to start from the beginning.
5	`limit`	integer	Yes	Maximum number of storage entries to return in one call.

Response

Type	Description
object	`{storage: Record<keyHash, {key: string, value: string}>, nextKey?: string}` — `nextKey` is present when more entries follow and can be passed as `startKey` for the next page.

Example request

1curl https://bsc.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "debug_storageRangeAt",
7    "params": [
8        "0x0000000000000000000000000000000000000000000000000000000000000000",
9        0,
10        "0x8894E0a0c962CB723c1976a4421c95949bE2D4E3",
11        "0x0000000000000000000000000000000000000000000000000000000000000000",
12        5
13      ],
14    "id": 1
15  }'

Try it live in the BNB Smart Chain playground.

Errors & troubleshooting

Code	Message	Cause
`-32601`	`Method not found`	debug namespace not enabled on the node.
`-32602`	`Invalid params`	Any required parameter is missing, malformed, or txIndex is out of range for the block.
`-32000`	`block not found`	Block hash not found or the node lacks state for that block (archive node required for historical blocks).

Common pitfalls

Keys come back as raw keccak256 hashes, so you rebuild mapping entries and dynamic-array slots by hand from the original key preimages.
Historical blocks require full archive state. A pruned node answers only for the most recent window.
A large contract holds thousands of slots and returns a bulky response, so set a sensible limit and follow nextKey page by page. Expect throttling on lower tiers.

Supported networks

Mainnet — Chain ID: 56
Testnet — Chain ID: 97