Getting Started with Defender

This setup shows how to pause contract on Spotter alert.

Setup Defender

• Create a Defender relay and send some native currency (ETH, BNB, etc) to this address, so it can cover transaction cost.
• Create a Defender autotask with webhook trigger and connect your relayer to it.

Here is an example of the autotask code to pause your contract.

const { Relayer } = require('defender-relay-client');
const { ethers } = require('ethers');
const your_contract = "0x72876a20Ca6b383b5401CD5FC97ed693d26dF43C"
exports.handler = async function(event) {
  if('subscribe' in event.request.body
    && 'address' in event.request.body.subscribe
    && event.request.body.subscribe.address == your_contract) {
      console.log(event.request.body.subscribe);
  	  const relayer = new Relayer(event);
      let ABI = [
        "function pause()"
      ];
      let iface = new ethers.utils.Interface(ABI);
      const tx_pause = await relayer.sendTransaction({
        to: your_contract, 
        value: 0, 
        gasLimit: '100000', 
        speed: 'fast', 
        data: iface.encodeFunctionData("pause", [])
      });
     console.log("tx pause sended", tx_pause.hash);
  }
  return "ok";
}

Using webhook to receive Spotter alert

Use /webhook command in Spotter telegram bot and send URL webhook from defender.

Setup Spotter subscription

Use /add command in Spotter to subscribe on alerts for the addresses of interest. For the example above it is 0x72876a20Ca6b383b5401CD5FC97ed693d26dF43C on BSC.