Overview
Fetches the complete orderbook for a prediction market by reading all escrow applications created by the market contract. The orderbook is organized into YES and NO sides, each containing bids (buy orders) and asks (sell orders).
Only includes limit orders (slippage = 0) with remaining unfilled quantity.
Method Signature
async getOrderbook(marketAppId: number): Promise<Orderbook>
Parameters
The market application ID on the Algorand blockchain
Returns
Returns an Orderbook object structured as follows:
All orders for the YES outcomeBuy orders for YES tokens
Sell orders for YES tokens
All orders for the NO outcomeSell orders for NO tokens
OrderbookEntry Type
Each OrderbookEntry contains:
Price in microunits (e.g., 500000 = $0.50)
Remaining quantity in microunits (e.g., 1000000 = 1 share)
The escrow application ID for this order
Algorand address of the order owner
Example Usage
import { AlphaClient } from '@alpha-arcade/sdk';
import algosdk from 'algosdk';
const algodClient = new algosdk.Algodv2('', 'https://mainnet-api.algonode.cloud', 443);
const indexerClient = new algosdk.Indexer('', 'https://mainnet-idx.algonode.cloud', 443);
const account = algosdk.mnemonicToSecretKey('your mnemonic...');
const client = new AlphaClient({
algodClient,
indexerClient,
signer: algosdk.makeBasicAccountTransactionSigner(account),
activeAddress: account.addr.toString(),
matcherAppId: 741347297,
usdcAssetId: 31566704,
});
// Fetch markets and get orderbook
const markets = await client.getLiveMarkets();
const orderbook = await client.getOrderbook(markets[0].marketAppId);
console.log('YES Bids:', orderbook.yes.bids);
console.log('YES Asks:', orderbook.yes.asks);
console.log('NO Bids:', orderbook.no.bids);
console.log('NO Asks:', orderbook.no.asks);
Finding Best Bid/Ask
To find the best available prices:
const orderbook = await client.getOrderbook(marketAppId);
// Best bid for YES (highest buy price)
const bestYesBid = orderbook.yes.bids
.sort((a, b) => b.price - a.price)[0];
if (bestYesBid) {
console.log(`Best YES bid: $${bestYesBid.price / 1e6}`);
console.log(`Quantity available: ${bestYesBid.quantity / 1e6} shares`);
}
// Best ask for YES (lowest sell price)
const bestYesAsk = orderbook.yes.asks
.sort((a, b) => a.price - b.price)[0];
if (bestYesAsk) {
console.log(`Best YES ask: $${bestYesAsk.price / 1e6}`);
console.log(`Quantity available: ${bestYesAsk.quantity / 1e6} shares`);
}
How It Works
- Discovers escrow apps: Queries the Algorand indexer for all applications created by the market’s contract address
- Reads global state: Fetches and decodes the global state of each escrow app
- Filters limit orders: Only includes orders with
slippage === 0 and unfilled quantity
- Categorizes orders: Organizes by position (YES/NO) and side (buy/sell)
Notes
- Quantities are in microunits (1,000,000 = 1 share)
- Prices are in microunits (500,000 = $0.50)
- Only active limit orders are included (market orders with slippage > 0 are excluded)
- The orderbook is fetched directly from the blockchain, so it reflects real-time on-chain state
