Smart Contracts

enum OrderType { LIMIT, DCA }        // uint8: 0, 1
enum TriggerDir { BELOW, ABOVE }     // uint8: 0, 1

struct Order {
  address owner;         // order creator, receives proceeds
  address tokenIn;       // token pulled from owner
  address tokenOut;      // token delivered to owner
  address priceFeed;     // Chainlink feed for LIMIT triggers
  uint256 amountIn;      // pulled per execution
  uint256 minAmountOut;  // slippage guard per execution
  int256  triggerPrice;  // 8-dec Chainlink units; 0 = no condition
  uint64  interval;      // DCA seconds between runs
  uint64  nextExecAt;    // DCA earliest next run
  uint64  expiry;        // unix; 0 = never
  uint32  remainingRuns; // LIMIT: 1
  uint8   orderType;     // 0 LIMIT | 1 DCA
  uint8   triggerDir;    // 0 below | 1 above
  bool    active;
}

function placeOrder(
  address tokenIn, address tokenOut, address priceFeed,
  uint256 amountIn, uint256 minAmountOut,
  int256 triggerPrice, uint8 triggerDir, uint8 orderType,
  uint64 interval, uint32 runs, uint64 expiry
) external returns (uint256 id);

function canExecute(uint256 id)
  external view returns (bool ok, string memory reason);

function executeOrder(uint256 id, address[] calldata path)
  external returns (uint256 amountOut);   // permissionless

function cancelOrder(uint256 id) external; // owner only

function setMaxPriceAge(uint32 age) external; // owner only

event OrderPlaced(uint256 indexed id, address indexed owner,
  address tokenIn, address tokenOut, uint8 orderType, uint256 amountIn);
event OrderExecuted(uint256 indexed id, address indexed keeper,
  uint256 amountIn, uint256 amountOut, uint32 remainingRuns);
event OrderCancelled(uint256 indexed id);