.claude/skills/crane-utilities/SKILL.md
This skill should be used when the user asks about "set collections", "AddressSet", "Bytes32Set", "math utilities", "ConstProdUtils", "AMM math", "hash functions", "BetterMath", "pagination", "EIP-712", "cryptography", or needs utility libraries for Crane Diamond development.
npx skillsauth add cyotee/crane crane-utilitiesInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
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Crane provides utility libraries for collections, math, cryptography, and common operations.
Diamond storage-compatible set implementations for unique value collections.
| Type | File | Use Case |
|------|------|----------|
| AddressSet | AddressSetRepo.sol | Unique addresses (operators, whitelist) |
| Bytes32Set | Bytes32SetRepo.sol | Unique hashes, identifiers |
| Bytes4Set | Bytes4SetRepo.sol | Function selectors, interface IDs |
| StringSet | StringSetRepo.sol | Unique strings |
| UInt256Set | UInt256SetRepo.sol | Unique numeric IDs |
import {AddressSet, AddressSetRepo} from "@crane/contracts/utils/collections/sets/AddressSetRepo.sol";
// In your Repo
struct Storage {
AddressSet operators;
}
// Operations
AddressSetRepo._add(set, value); // Add value, idempotent
AddressSetRepo._remove(set, value); // Remove value, idempotent
AddressSetRepo._contains(set, value); // Check presence
AddressSetRepo._length(set); // Get count
AddressSetRepo._index(set, idx); // Get value at index
AddressSetRepo._indexOf(set, value); // Get index of value
AddressSetRepo._asArray(set); // Get all values as array
For large sets, use pagination:
// Get page of results
(address[] memory page, bool hasMore) = AddressSetRepo._getPage(
set,
pageIndex, // 0-based page number
pageSize // Items per page
);
Core AMM math for constant product pools (xy=k):
import {ConstProdUtils} from "@crane/contracts/utils/math/ConstProdUtils.sol";
using ConstProdUtils for uint256;
// Calculate output for swap
uint256 amountOut = ConstProdUtils._purchaseQuote(
amountIn, // Amount being sold
reserveIn, // Reserve of input token
reserveOut, // Reserve of output token
feeNumerator // Fee (e.g., 9970 for 0.3%)
);
// Calculate input needed for desired output
uint256 amountIn = ConstProdUtils._saleQuote(
amountOut,
reserveIn,
reserveOut,
feeNumerator
);
// Optimal swap amount for balanced deposit
uint256 saleAmt = ConstProdUtils._quoteSaleAmountIn(
amountIn,
reserveIn,
reserveOut,
feeNumerator
);
// Sort reserves by token address
(uint256 knownReserve, uint256 unknownReserve) = ConstProdUtils._sortReserves(
knownToken,
token0,
reserve0,
reserve1
);
Extended math operations including 512-bit arithmetic:
import {Uint512, BetterMath} from "@crane/contracts/utils/math/BetterMath.sol";
using BetterMath for uint256;
using BetterMath for Uint512;
// Safe operations
uint256 sum = a._add(b); // Checked addition
uint256 diff = a._sub(b); // Checked subtraction
uint256 prod = a._mul(b); // Checked multiplication
uint256 quot = a._div(b); // Checked division
// 512-bit multiplication (for intermediate precision)
Uint512 memory product = a._mul512(b);
uint256 result = product._div(c);
// Min/max
uint256 smaller = a._min(b);
uint256 larger = a._max(b);
// Percentage calculations
uint256 portion = total._mulDivDown(numerator, denominator);
uint256 portionUp = total._mulDivUp(numerator, denominator);
import {EIP712Repo} from "@crane/contracts/utils/cryptography/EIP712/EIP712Repo.sol";
// Initialize in DFPkg
EIP712Repo._initialize("MyContract", "1");
// Build domain separator
bytes32 domainSeparator = EIP712Repo._domainSeparator();
// Hash typed data
bytes32 digest = keccak256(abi.encodePacked(
"\x19\x01",
domainSeparator,
structHash
));
Optimized hashing:
import {BetterEfficientHashLib} from "@crane/contracts/utils/BetterEfficientHashLib.sol";
using BetterEfficientHashLib for bytes;
// Hash bytes efficiently
bytes32 hash = someBytes._hash();
// Hash for CREATE3 salt
bytes32 salt = abi.encode(value)._hash();
import {BetterStrings} from "@crane/contracts/utils/BetterStrings.sol";
using BetterStrings for string;
string memory result = str1._concat(str2);
bool isEmpty = str._isEmpty();
uint256 len = str._length();
import {BetterBytes} from "@crane/contracts/utils/BetterBytes.sol";
using BetterBytes for bytes;
bytes memory slice = data._slice(start, length);
bytes memory concat = data1._concat(data2);
import {Bytes32} from "@crane/contracts/utils/Bytes32.sol";
import {Bytes4} from "@crane/contracts/utils/Bytes4.sol";
using Bytes32 for bytes32;
using Bytes4 for bytes4;
// Convert to hex string
string memory hex32 = someHash._toHexString();
string memory hex4 = someSelector._toHexString();
import {BetterAddress} from "@crane/contracts/utils/BetterAddress.sol";
using BetterAddress for address;
// Check if address is contract
bool isContract = addr._isContract();
// Safe ETH transfer
addr._sendValue(amount);
Network and protocol constants:
import "@crane/contracts/constants/Constants.sol";
// Global constants
uint256 constant WAD = 1e18;
uint256 constant RAY = 1e27;
// Network-specific
import "@crane/contracts/constants/networks/BASE_MAIN.sol";
// Provides addresses for Base mainnet
// Protocol constants
import "@crane/contracts/constants/protocols/utils/permit2/PERMIT2_CONSTANTS.sol";
// Provides Permit2 addresses
contracts/utils/
├── collections/
│ └── sets/
│ ├── AddressSetRepo.sol
│ ├── Bytes32SetRepo.sol
│ ├── Bytes4SetRepo.sol
│ ├── StringSetRepo.sol
│ └── UInt256SetRepo.sol
├── cryptography/
│ ├── EIP712/
│ │ └── EIP712Repo.sol
│ ├── ERC5267/
│ │ └── ERC5267Facet.sol
│ └── hash/
│ └── *.sol
├── math/
│ ├── BetterMath.sol
│ ├── ConstProdUtils.sol
│ └── [Protocol]Utils.sol
├── BetterAddress.sol
├── BetterBytes.sol
├── BetterEfficientHashLib.sol
├── BetterStrings.sol
├── Bytes32.sol
├── Bytes4.sol
└── UInt256.sol
For detailed utility patterns and examples:
references/utility-patterns.md - Complete usage patterns and examplesdevelopment
Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".
documentation
Write to contracts and send transactions. Use when executing state-changing contract functions.
development
HTTP and WebSocket transports for blockchain connectivity. Use when configuring network connections.
data-ai
Read contract data with type-safe ABI. Use when querying smart contract view/pure functions.