Order

This section explains how orders work in the Opinion prediction market, including order types, sides, and amount specifications.

Order Types

Type	Enum Value	Description	Price Parameter
Market Order	OrderType.MARKET_ORDER	Execute immediately at best available price	Ignored, price is always "0" for market order.
Limit Order	OrderType.LIMIT_ORDER	Execute only at specified price or better	Required (e.g., "0.50")

Order Sides

Side	Enum Value	Description
BUY	OrderSide.BUY	Purchase outcome tokens (predict event occurs)
SELL	OrderSide.SELL	Sell outcome tokens (close position or short)

Price

Prices represent implied probability:

• Valid range: 0.01 to 0.99

• Maximum 4 decimal places

• "0.50" = 50% probability, costs $0.50 per token, pays $1.00 if correct

Amount Specifications

You must specify exactly one of:

Parameter	Type	Usage
makerAmountInQuoteToken	string	Specify USDT to spend/receive
makerAmountInBaseToken	string	Specify exact token quantity

Examples:

• BUY order at price 0.60, spending 100 USDT -> receives ~166.67 tokens

• SELL order at price 0.60, selling 200 tokens -> receives 120 USDT

Restrictions

Side	Order Type	Allowed Amount
BUY	Market	makerAmountInQuoteToken only
SELL	Market	makerAmountInBaseToken only
BUY	Limit	Either
SELL	Limit	Either

Placing Orders

place-orders.ts

import { OrderSide, OrderType, type PlaceOrderDataInput } from '@opinion-labs/opinion-clob-sdk';

// Limit BUY: spend 10 USDT on YES tokens at 0.5
const buyOrder: PlaceOrderDataInput = {
  marketId: 123,
  tokenId: 'yes_token_id',
  side: OrderSide.BUY,
  orderType: OrderType.LIMIT_ORDER,
  price: '0.5',
  makerAmountInQuoteToken: '10',
};
const result = await client.placeOrder(buyOrder);

// Market BUY: spend 10 USDT at market price
const marketBuy: PlaceOrderDataInput = {
  marketId: 123,
  tokenId: 'yes_token_id',
  side: OrderSide.BUY,
  orderType: OrderType.MARKET_ORDER,
  price: '0',
  makerAmountInQuoteToken: '10',
};
const result2 = await client.placeOrder(marketBuy);

// Limit SELL: sell 20 YES tokens at 0.6
const sellOrder: PlaceOrderDataInput = {
  marketId: 123,
  tokenId: 'yes_token_id',
  side: OrderSide.SELL,
  orderType: OrderType.LIMIT_ORDER,
  price: '0.6',
  makerAmountInBaseToken: '20',
};
const result3 = await client.placeOrder(sellOrder);

Cancelling Orders

cancel-orders.ts

// Cancel single order
await client.cancelOrder('order_123');

// Cancel multiple orders
const results = await client.cancelOrdersBatch(['order_1', 'order_2', 'order_3']);

// Cancel all open orders (optionally filter by market/side)
const summary = await client.cancelAllOrders({ marketId: 123, side: OrderSide.BUY });
console.log(`Cancelled: ${summary.cancelled}, Failed: ${summary.failed}`);

Batch Operations

batch-operations.ts

// Place multiple orders at once
const orders = [order1, order2, order3];
const results = await client.placeOrdersBatch(orders, true);

for (const r of results) {
  if (r.success) {
    console.log(`Order ${r.index}: placed successfully`);
  } else {
    console.log(`Order ${r.index}: failed - ${r.error}`);
  }
}

Note: The placeOrdersBatch method accepts an optional second parameter checkApproval (default false). When set to true, it calls enableTrading() once before placing any orders.

Best Practices

• Review orderbook before placing market orders to assess slippage

• Break large orders into smaller limit orders to minimize market impact

• Validate price is within [0.01, 0.99] range before submission

• Use batch methods for multiple orders to reduce latency