Tutorial: Order Trigger Bot

5min

Introduction
Order Trigger Bots (Trigger Bots) are responsible for marking orders that satisfy the trigger condition, including: 
Trigger Market Orders - Stop Market and Take Profit 
Trigger Limit Orders - Stop Limit and Take Profit Limit
Trigger Bots receive a small compensation for each successfully marked order.
See Keepers & Decentralised Orderbook﻿ for a technical explanation of how the decentralised orderbook (DLOB) and matching incentives work.
Trigger Bots are similar to Tutorial: Order Matching Bot﻿ in that they: 
also maintain a local copy of the Keepers & Decentralised Orderbook﻿; 
do not require the operator to manage collateral; and 
receive a small reward for performing their duties.
Getting Started
The reference implementation of a Trigger Bot is available here.
Follow the instructions at Keeper Bots﻿ to set the required environment variables and make sure a ClearingHouseUser is initialised.
Start the Trigger Bot:
Shell
yarn run dev:trigger
yarn run dev:trigger
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Technical Explanation
1. Get nodes from the DLOB that are ready to be triggered
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The DLOB implementation includes a method for getting orders ready to be triggered:
TypeScript
const market = this.driftClient.getMarketAccounts()[0]; // get a MarketAccount

const oraclePriceData =
    this.driftClient.getOracleDataForMarket(marketIndex);

const nodesToTrigger = this.dlob.findNodesToTrigger(
    marketIndex,
    this.slotSubscriber.getSlot(),
    oraclePriceData.price
);
const market = this.driftClient.getMarketAccounts()[0]; // get a MarketAccount

const oraclePriceData =
    this.driftClient.getOracleDataForMarket(marketIndex);

const nodesToTrigger = this.dlob.findNodesToTrigger(
    marketIndex,
    this.slotSubscriber.getSlot(),
    oraclePriceData.price
);
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2. Call trigger_order on DriftClient 
TypeScript
const user = this.userMap.get(nodeToTrigger.node.userAccount.toString());
const txSig = await this.driftClient.triggerOrder(
    nodeToTrigger.node.userAccount,
    user.getUserAccount(),
    nodeToTrigger.node.order
)
const user = this.userMap.get(nodeToTrigger.node.userAccount.toString());
const txSig = await this.driftClient.triggerOrder(
    nodeToTrigger.node.userAccount,
    user.getUserAccount(),
    nodeToTrigger.node.order
)
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