> ## Documentation Index
> Fetch the complete documentation index at: https://docs.skale.space/llms.txt
> Use this file to discover all available pages before exploring further.

# Precompiled Contracts

> Precompiled Contracts on SKALE

SKALE Chains ship extra precompiled contracts beyond Ethereum’s defaults (e.g., `ecrecover`, `sha256`, `modexp`). These precompiles unlock native file storage, logging, randomness, and configuration helpers without deploying custom contracts—ideal for builders who want performance and simplicity.

| Address | Function                 | Sender Who May Call | Description                                                                                                                                                                                            |
| ------- | ------------------------ | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| 0x0A    | readChunk                | Any                 | Reads chunk from file from specific position with specific length                                                                                                                                      |
| 0x0B    | createFile               | Filestorage Only    | Creates an address for an empty file                                                                                                                                                                   |
| 0x0C    | uploadChunk              | Filestorage Only    | Uploads 1MB chunk of data from specific position in specific file by file owner                                                                                                                        |
| 0x0D    | getFileSize              | Any                 | Returns size of file                                                                                                                                                                                   |
| 0x0E    | deleteFile               | Filestorage Only    | Deletes file from filestorage system                                                                                                                                                                   |
| 0x0F    | createDirectory          | Filestorage Only    | Creates directory in filestorage system                                                                                                                                                                |
| 0x10    | deleteDirectory          | Filestorage Only    | Deletes directory in filestorage system                                                                                                                                                                |
| 0x11    | calculateFileHash        | Any                 | Calculates and writes SHA256 hash of file in same directory *\<NAME\_OF\_FILE>.\_hash*                                                                                                                 |
| 0x12    | logTextMessage           | Any                 | <div>Logs a message: <br /><ul><li>0 - Normal</li><li>1 - Debug</li><li>2 - Trace</li><li>3 - Warning</li><li>4 - Error</li><li>5 - Fatal</li></ul><br /><p>Used for IMA SKALE Chain Testing</p></div> |
| 0x13    | getConfigVariableUint256 | Any                 | Returns SKALE Chain config uint256 for IMA SKALE Chain contracts. Used for reading BLS common public key                                                                                               |
| 0x14    | getConfigVariableAddress | Any                 | Returns SKALE Chain config address for IMA SKALE Chain testing                                                                                                                                         |
| 0x15    | getConfigVariableString  | Any                 | Returns SKALE Chain config string for IMA SKALE Chain testing                                                                                                                                          |
| 0x16    | fnReserved0x16           | Any                 | Reserved                                                                                                                                                                                               |
| 0x16    | getConfigPermissionsFlag | Any                 | Returns SKALE Chain config boolean for IMA SKALE Chain testing                                                                                                                                         |
| 0x18    | getBlockRandom           | Any                 | Return a random number based on BLS threshold signature common coin of the current block                                                                                                               |
| 0x19    | getIMABLSPublicKey       | Any                 | Returns relevant BLSPublicKey according to block timestamp                                                                                                                                             |

Use these precompiles to build richer experiences (randomness for gaming, native storage for media, config reads for bridges) without extra gas costs or custom infra.