Automatic market maker on Stellar Network
Latest commit 2301334 Jan 21, 2017 @julesGoullee bot delete preview offers & timer to launch other & main entrie point…
… to require bot or oracle


Automatic market maker on Stellar Network

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Garnet is a market-maker bot for the Stellar network. It automatically creates offers on the market depending on its wallets and on market prices.

Its main goal is not to earn money but to help the expansion and introduction of anchors into Stellar network. It allows anchors to diffuse their assets, and users to send path payments with assets they do not hold. It is made to play the essential role of real market-makers until there are enough players on the network.

This repository shows my original idea to strengthen the network and to show a proof-of-concept implementation. It is not intended to be used on public network for now, but to serve as a starter-kit for an anchor.

The bot is launched with an account seed created specifically for it. It first checks his trustlines and balances. Then it creates passive offers for everything the account holds, with rates defined by an oracle. The Oracle is an independent module that tells the bot prices and amount to sell for a pair of assets.

In this project, there are three different oracles:

  • One very basic, that sells everything it holds for a price of 1:1 (oracles/simple.js)
  • One that fetch current market prices of common currences (USD, EUR, BTC, ...) from public APIs (currently (oracles/realWorld.js)
  • One that reads prices and amount in a Redis database. (oracles/redis.js)

Use case

When an anchor wants to get into the stellar network, no one holds its assets. There must be market makers that trust this new anchor to allow path payments and trading of its assets. At the very beginning, an anchor can become its own market maker, choose to trust some others anchor's assets, inject its own asset into the bot and get others assets in exchange. The bot will then, lose anchor assets, but gain others. The anchor must invest money into the market, but it will get others currencies claimable on the real world afterwards. At the end, the anchor assets will be flowing on the network and exchanged by Stellar users. To stay fair and not to lose money, the bot must use an oracle that announce correct market prices.

Running demo

You can watch the current balances and offers for on our demo bot running on testnet on Stellar Portal

On this account, you can see that the bot holds EUR, USD, and BTC and has offers with current market prices. If you send it assets, you will see that it is updating his offers. (If you want to receive some assets, send us a message with your public key and we will fund you)


You can run your own bot and test its behaviour on the testnet. You can use tools like Stellar Portal or Stellar Laboratory for managing and monitoring bot accounts.

  • Create a bot account
  • Create some issuer accounts, create trustlines to issuers assets (corresponding to known currencies, EUR, USD...) on the bot account
  • Fund the bot account with one or two assets
  • Watch offers that it has created.


  • NodeJS v7+

How to use

The easiest way to run the bot is from command line.

  • Install node dependencies
  • Run npm start with SEEDenvironment variable filled with the bot's secret seed.
$ npm install
$ SEED=SDJEUIJRE npm run bot

Npm Installation:

You can implement your own oracle. This is an example of a bot instance with a simple oracle that sells everything at price 1:1 except Lumens.

You Oracle just have to implement two methods getPrice and getAmount. Please notice that they must return promises, and are implemented as async functions here. Assets are instance of StellarSDK's Asset class.

$ npm install garnet-market-maker
const Bot = require('garnet-market-maker').Bot;

class Oracle {

  async getPrice(assetSelling, assetBuying){ // For example 1:1 price

    return {
      n: 1,
      d: 1


  async getAmount(wallet){ // For example bid all ressource

    if(wallet.asset.isNative() ){

      return 0;


    return wallet.balance;



const SEED = 'yourSeed';
const oracle = new Oracle();
const bot = new Bot(SEED, oracle);;


This bot is just a proof-of-concept for a market-maker bot to support the stellar network expansion and new anchors introduction. It is not intended to be used on the real public network as the currently implemented oracle is not returning perfectly correct market prices and may lose some money value. It is currently configured to run on testnet.

The plan is to increase robustness and precision of market prices and external oracles integrations. If anchors want to use it, the code can be adapted to connect their own market estimations, contact us for more information.

If you have something interesting to share with us, we're open to issues or PM.