debug_storageRangeAt

debug_storageRangeAt reads a contract's raw storage on Arbitrum One (chain ID 42161, gas paid in ETH) exactly as it stood right after a chosen transaction in a chosen block executed. You give it a block hash, the index of the transaction within that block, the contract address, a starting storage-key hash, and a page size; it walks the contract's storage trie from that key and returns one page of {key, value} slots plus a nextKey cursor when more remain. Because Arbitrum One is a Nitro rollup with its own ArbOS state, this lets you reconstruct the precise L2 storage of any contract at any historical point. Send the request to https://arbitrum.therpc.io/YOUR_API_KEY.

Use cases

• Dump a contract's full storage layout at a specific transaction boundary for a post-mortem of an Arbitrum One DeFi incident (GMX, Aave, or Camelot pools, for example).
• Verify the slot assignments of an upgradeable proxy on Arbitrum One against its expected layout before and after an upgrade.
• Compare a contract's storage immediately before and after a suspicious transaction to pinpoint which slot a call changed.

Parameters

Response

Example request

1curl https://arbitrum.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        "0x0000000000000000000000000000000000000000",
11        "0x0000000000000000000000000000000000000000000000000000000000000000",
12        5
13      ],
14    "id": 1
15  }'

Try it live in the Arbitrum One playground.

Errors & troubleshooting

Common pitfalls

• Keys come back as raw keccak256 hashes, so mapping entries and dynamic-array elements must be decoded by hand — the method does not know your Solidity variable names.
• Historical blocks need an archive Arbitrum One node; a pruned node only holds recent ArbOS state and returns "block not found" (-32000) for older blocks.
• Large contracts on Arbitrum One can hold thousands of slots; always set a sensible limit and follow nextKey to page rather than trying to pull everything at once.

Supported networks

• Mainnet — Chain ID: 42161
• Sepolia — Chain ID: 421614

See also

• debug_traceTransaction
• debug_traceCall
• trace_replayTransaction

1curl https://arbitrum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"debug_storageRangeAt","params":["0x0000000000000000000000000000000000000000000000000000000000000000",0,"","0x0000000000000000000000000000000000000000000000000000000000000000",10]}'