Devpack Wrapper Reference

Back to Syscalls

The devpack provides syscall access at two abstraction levels.

Low-Level: Syscalls.sol

Located at devpack/contracts/Syscalls.sol. Provides typed wrappers for the Neo N3 syscall surface, plus convenience functions for native contract calls.

Key features:

• Typed wrappers for the registered syscall surface exposed as internal Solidity functions
• Data structures: Block, Transaction, Signer, StorageContext, Iterator, Notification
• Constants: trigger types, witness scopes, witness conditions, named curve hashes
• Native contract script hash constants for the runtime-supported native contracts: NEO, GAS, ContractManagement, Policy, Oracle, RoleManagement, Notary, Treasury, Ledger, CryptoLib, and StdLib

High-Level: Ergonomic Libraries

Library	File	Built On
Storage	devpack/libraries/Storage.sol	System.Storage.* syscalls
Runtime	devpack/libraries/Runtime.sol	System.Runtime.* syscalls
Neo	devpack/libraries/Neo.sol	Multiple syscall categories + native calls

The Storage library adds batch operations, typed accessors (putUint256, getAddress, putBool), iterator helpers (findKeys, findValues, count), key derivation for mappings and arrays, and storage patterns like expiration and checksummed writes.

// Low-level: direct syscall
Syscalls.StorageContext memory ctx = Syscalls.getStorageContext();
Syscalls.storagePut(ctx, "key", abi.encode(42));

// High-level: ergonomic wrapper
Storage.putUint256("key", 42);
uint256 value = Storage.getUint256("key");