docs(examples/ocean-dbtc-burning-bot): DFIP 2201-A, an automated wallet bot to burn dBTC

.eslintrc

@@ -9,7 +9,8 @@
   "ignorePatterns": [
     "dist",
     "*.json",
-    "website"
+    "website",
+    "examples"
   ],
   "rules": {
     "curly": [

examples/ocean-dbtc-burning-bot/.gitignore

@@ -0,0 +1,20 @@
+# Yarn
+.yarn/*
+!.yarn/patches
+!.yarn/releases
+!.yarn/plugins
+!.yarn/sdks
+!.yarn/versions
+.pnp.*
+
+# Node Modules
+node_modules
+package-lock.json
+
+# dist & pack
+dist
+*.tgz
+.next
+tsconfig.build.tsbuildinfo
+
+

examples/ocean-dbtc-burning-bot/README.md

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+# Ocean dBTC Burning Bot
+
+> [DFIP 2201-A: Solving unbacked dBTC](https://github.com/DeFiCh/dfips/issues/101)
+
+Part of DFIP 2201-A requirement; an automated wallet bot to burn dBTC.
+
+This is a very simple dBTC burning bot that is deployed
+on [df1qc8ptw6vc9588w6f53fvcjsjx0fntv3men407a9](https://defiscan.live/address/df1qc8ptw6vc9588w6f53fvcjsjx0fntv3men407a9)
+address.
+
+## Implementation
+
+> BURN-DFI -> DFI Rewards -> BTC Swap -> BTC Burn
+
+With a predefined [`main()`](./src/main.ts) as the entry function, this bot take all DFI accumulated from BURN-DFI pool
+rewards (3.5% from BTC-DFI). Swapping them from DFI to BTC and then finally sending it to the burn
+address `8defichainBurnAddressXXXXXXXdRQkSm`.
+
+## Deployment
+
+Deployed on AWS lambda, this bot is compiled with [vercel/ncc](https://github.com/vercel/ncc) via [build.js](./build.js)
+which produce a single file that support TypeScript and binary addons (tiny-secp256k1).
+
+```shell
+npm i
+npm run build
+
+# Upload ./dist/main.zip into AWS Lambda
+```

examples/ocean-dbtc-burning-bot/build.js

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+const util = require('util')
+const exec = util.promisify(require('child_process').exec)
+
+function handleExec (res) {
+  if (res.stderr) {
+    console.error(res.stderr)
+  }
+
+  if (res.error) {
+    console.log(res.error.message)
+    throw res.error
+  }
+}
+
+/**
+ * Build and ZIP for AWS Lambda Execution
+ */
+async function buildLambda (file = 'main') {
+  {
+    const command = `npx --package @vercel/ncc ncc build ./src/${file}.ts --source-map -o ./dist/${file}`
+    const res = await exec(command, { cwd: __dirname })
+    handleExec(res)
+  }
+
+  {
+    const res = await exec(`zip -r -j ./dist/${file}.zip ./dist/${file}/*`)
+    handleExec(res)
+  }
+
+  console.log(`src/${file}.ts -> dist/${file}.zip`)
+}
+
+buildLambda().catch(
+  e => {
+    console.error(e)
+  }
+)

examples/ocean-dbtc-burning-bot/package.json

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+{
+  "private": true,
+  "scripts": {
+    "build": "node build.js"
+  },
+  "dependencies": {
+    "@defichain/jellyfish-wallet-classic": "latest",
+    "@defichain/whale-api-client": "latest",
+    "@defichain/whale-api-wallet": "latest"
+  },
+  "devDependencies": {
+    "@vercel/ncc": "latest"
+  }
+}

examples/ocean-dbtc-burning-bot/src/main.ts

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+import { WIF } from '@defichain/jellyfish-crypto'
+import { WalletClassic } from '@defichain/jellyfish-wallet-classic'
+import { WhaleApiClient } from '@defichain/whale-api-client'
+import { fromAddress } from '@defichain/jellyfish-address'
+import { MainNet } from '@defichain/jellyfish-network'
+import { WhaleWalletAccount } from '@defichain/whale-api-wallet'
+import { CTransactionSegWit, TransactionSegWit } from '@defichain/jellyfish-transaction'
+import { BigNumber } from 'bignumber.js'
+import { AddressToken } from '@defichain/whale-api-client/dist/api/address'
+
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+const BURN_ADDRESS_SCRIPT = fromAddress('8defichainBurnAddressXXXXXXXdRQkSm', 'mainnet')!.script
+
+/**
+ * Initialize WhaleApiClient connected to ocean.defichain.com/v0
+ */
+const client = new WhaleApiClient({
+  url: 'https://ocean.defichain.com',
+  version: 'v0'
+})
+
+// You can `dumpprivkey [address]` with defi-cli, only Bech32 address (df1...) are supported.
+const PRIVATE_KEY = 'PRIVATE_KEY_IN_WIF'
+
+export async function main (): Promise<void> {
+  const wallet = new WalletClassic(WIF.asEllipticPair(PRIVATE_KEY))
+  const sequencer = new BurnProgram(client, wallet)
+
+  // Refill UTXO if balance is getting low
+  if (await sequencer.accountToUTXO()) {
+    return
+  }
+
+  // Burn dBTC by sending to burn address
+  if (await sequencer.burnDBTC()) {
+    return
+  }
+
+  // Swap DFI to BTC
+  await sequencer.swapDFIDBTC()
+}
+
+export class BurnProgram {
+  constructor (
+    private readonly client: WhaleApiClient,
+    private readonly wallet: WalletClassic,
+    private readonly account = new WhaleWalletAccount(client, wallet, MainNet)
+  ) {
+  }
+
+  /**
+   * Refill UTXO when there is less than 1.1 UTXO.
+   */
+  async accountToUTXO (): Promise<boolean> {
+    const utxoBalance = await this.getUTXOBalance()
+    console.log(`UTXO Balance: ${utxoBalance.toFixed()}`)
+
+    if (utxoBalance.gte(new BigNumber('1.1'))) {
+      return false
+    }
+    console.log('Refilling UTXO')
+
+    const script = await this.account.getScript()
+    const txn = await this.account.withTransactionBuilder().account.accountToUtxos({
+      from: script,
+      balances: [
+        {
+          token: 0,
+          amount: new BigNumber('1.0')
+        }
+      ],
+      mintingOutputsStart: 2 // 0: DfTx, 1: change, 2: minted utxos (mandated by jellyfish SDK)
+    }, script)
+
+    await this.send(txn)
+    return true
+  }
+
+  /**
+   * Burn dBTC there is more than 0.1 BTC
+   */
+  async burnDBTC (): Promise<boolean> {
+    const dBTC = await this.getTokenBalance('BTC', new BigNumber('0.1'))
+    if (dBTC === undefined) {
+      return false
+    }
+    console.log(`Burning dBTC: ${dBTC.amount}`)
+
+    const script = await this.account.getScript()
+    const txn = await this.account.withTransactionBuilder().account.accountToAccount({
+      from: script,
+      to: [{
+        script: BURN_ADDRESS_SCRIPT,
+        balances: [{
+          token: parseInt(dBTC.id),
+          amount: new BigNumber(dBTC.amount)
+        }]
+      }]
+    }, script)
+
+    await this.send(txn)
+    return true
+  }
+
+  /**
+   * Swap DFI to dBTC when there is more than 100 DFI
+   */
+  async swapDFIDBTC (): Promise<boolean> {
+    const dfi = await this.getTokenBalance('DFI', new BigNumber('100'))
+    if (dfi === undefined) {
+      console.log('DFI Account balance less than 100')
+      return false
+    }
+    console.log(`Swap ${dfi.amount} DFI to dBTC`)
+
+    const script = await this.account.getScript()
+    const txn = await this.account.withTransactionBuilder().dex.compositeSwap({
+      poolSwap: {
+        fromScript: script,
+        toScript: script,
+        fromTokenId: 0,
+        toTokenId: 2,
+        fromAmount: new BigNumber(dfi.amount),
+        maxPrice: new BigNumber('9223372036854775807')
+      },
+      pools: []
+    }, script)
+
+    await this.send(txn)
+    return true
+  }
+
+  /**
+   * Get token balance from wallet with minBalance
+   */
+  private async getTokenBalance (symbol: string, minBalance: BigNumber): Promise<AddressToken | undefined> {
+    const address = await this.account.getAddress()
+    const tokens = await this.client.address.listToken(address, 200)
+
+    return tokens.find(token => {
+      return token.isDAT && token.symbol === symbol && new BigNumber(token.amount).gte(minBalance)
+    })
+  }
+
+  /**
+   * Get current wallet UTXO balance
+   */
+  private async getUTXOBalance (): Promise<BigNumber> {
+    const address = await this.account.getAddress()
+
+    return new BigNumber(await this.client.address.getBalance(address))
+  }
+
+  private async send (txn: TransactionSegWit): Promise<void> {
+    const hex: string = new CTransactionSegWit(txn).toHex()
+    const txId: string = await this.client.rawtx.send({ hex: hex })
+
+    console.log(`Send TxId: ${txId}`)
+  }
+}

examples/ocean-dbtc-burning-bot/tsconfig.json

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+{
+  "compilerOptions": {
+    "lib": [
+      "es2020"
+    ],
+    "target": "esnext",
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "strict": true,
+    "esModuleInterop": true,
+    "resolveJsonModule": true
+  },
+  "include": [
+    "src"
+  ]
+}