400.js

const baseBet = 1 * 100     // how many satoshis to bet initially
const target = 1.75         // target multiplier
const betMultiplier = 3.06  // what to multiply the bet size by when we lose a wager
const MAX_BET = 2000 * 100   // maximum bet amount to stop script at (satoshis)
const MAX_GAMES = -1        // maximum number of games to play before stopping (set to -1 for unlimited)
const BET_SPEED = 500      // time between bets in (ex 500 = 500ms = 0.5s)

let lossCount = 0
this.log(`Starting martingale with a base bet of ${baseBet/100} bits.`)

let running = true
let gameNum = 0
while (running) {
  let bet = betSize(lossCount)
  if (MAX_GAMES !== -1 && gameNum >= MAX_GAMES) {
    // stop after playing max num of games
    this.log(`Stopped after playing ${MAX_GAMES} games.`)
    running = false
  } else if (bet >= MAX_BET) {
    // stop if bet amount reaches max bet
    this.log(`Stopped due to max bet exceeded (${baseBet/100} bits.`)
    running = false
  } else {
    // make the bet and wait for the result
    const { multiplier } = await this.bet(bet, target)

    if (multiplier < target) { // loss
      lossCount++
      this.log(`Lost bet. Multiplying bet size by ${betMultiplier} for new bet size of ${bet/100} bits.`)
    } else { // win
      lossCount = 0
      this.log(`Won bet. Setting bet size to ${baseBet/100} bits.`)
    }
  }
  gameNum++
  await sleep(BET_SPEED)
}

function betSize(lossCount) {
  const bet = baseBet * Math.pow(betMultiplier, lossCount)
  return Math.round(bet / 100) * 100
}

function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms))
}