# Storage query (/docs/guides/evm/precompiles/storage-query)

| Property            | Value                                        |
| ------------------- | -------------------------------------------- |
| Rust implementation | `StorageQueryPrecompile`                     |
| Solidity interface  | None                                         |
| Address             | `0x0000000000000000000000000000000000000807` |
| Status              | Deployed · deprecation planned               |

This precompile has no named Solidity functions or four-byte function selector.
The complete call data is interpreted as a raw Substrate storage key. It returns
the stored SCALE-encoded bytes, or empty bytes when the key does not exist.

Only keys whose first 16 bytes match an authorized pallet prefix are accepted:
SubtensorModule, Swap, Balances, Proxy, Scheduler, Drand, Crowdloan, Sudo,
Multisig, and Timestamp.

Raw storage access is brittle because callers depend on runtime storage names,
hashers, key formats, and SCALE encodings.

## Planned deprecation [#planned-deprecation]

<Callout type="warning">
  Storage Query is still deployed and callable. Deprecation is planned, but it
  does not begin until suitable typed replacement coverage is available.
</Callout>

The planned lifecycle is:

1. Add typed views for all storage currently authorized through this
   precompile.
2. Soft-deprecate Storage Query. Existing calls continue to execute identically
   while the registry and documentation direct new callers to typed functions.
3. Allow a documented migration window for existing contracts and tooling.
4. Hard-deprecate Storage Query so calls return a descriptive precompile error.
5. Eventually disable the precompile through the existing Root-controlled
   precompile switch.

No migration-window length or activation block has been assigned. The general
lifecycle rules are described in
[Precompile design and lifecycle](/docs/guides/evm/precompile-design#phasing-out-raw-storage-reads).

## Replacement destinations [#replacement-destinations]

Typed coverage should be completed at existing domain addresses whenever a
compatible domain already exists. A new address is proposed only when no
existing precompile has a coherent responsibility for that state.

| Authorized storage prefix | Typed replacement                                                                                                                                                                                                                                                                          |
| ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `SubtensorModule`         | Extend [Staking V2](./staking-v2), [Metagraph](./metagraph), [Subnet](./subnet), [Neuron](./neuron), [Alpha](./alpha), [Leasing](./leasing), [UID lookup](./uid-lookup), [Address mapping](./address-mapping), and [Voting power](./voting-power), according to the meaning of each value. |
| `Swap`                    | Extend [Alpha](./alpha) with typed liquidity, fee, balancer, reservoir, initialization, and migration-status views.                                                                                                                                                                        |
| `Balances`                | Extend [Account balance](./account-balance) with typed account, issuance, lock, reserve, hold, and freeze views.                                                                                                                                                                           |
| `Proxy`                   | Extend [Proxy](./proxy) with typed announcement, last-call-result, and fee-payer views.                                                                                                                                                                                                    |
| `Crowdloan`               | Extend [Crowdloan](./crowdloan) with typed ID, contribution-limit, current-operation, and migration-status views.                                                                                                                                                                          |
| `Scheduler`               | Use the typed [Scheduler](./scheduler) precompile.                                                                                                                                                                                                                                         |
| `Drand`                   | Use the typed [Drand](./drand) precompile.                                                                                                                                                                                                                                                 |
| `Sudo`                    | No dedicated EVM precompile is proposed; this access must be addressed explicitly before Storage Query is deprecated.                                                                                                                                                                      |
| `Multisig`                | No dedicated EVM precompile is proposed; this access must be addressed explicitly before Storage Query is deprecated.                                                                                                                                                                      |
| `Timestamp`               | Use the typed [Timestamp](./timestamp) precompile; `getTimestamp()` is equivalent to the existing EVM `block.timestamp` value.                                                                                                                                                             |

Source: [`storage_query.rs`](https://github.com/RaoFoundation/subtensor/blob/main/precompiles/src/storage_query.rs)