Chainlink demo project for Harmony

This project mainly helps to deploy chainlink smart contracts to Harmony and run a consumer who makes the oracle request.

Chainlink related contracts that can be deployed are:

• LinkToken - chainlink crypto currency used to pay oracle providers
• Oracle - chainlink oracle contract deployed by oracle providers
• Consumer - contract that invokes chainlink oracle request

Requirements

• Node, Yarn

Installation

yarn install

Compile contracts

truffle compile

Deploy

Deploy LinkToken to Harmony testnet. Needs PRIVATE_KEY_LINK env variable set.

node scripts/link.js

Deploy oracle contract to Harmony testnet. Needs PRIVATE_KEY_ORACLE env variable set. Also, link token contract address from deployment above copied to the script oracle.js.

node scripts/oracle.js

Deploy consumer contract. Make sure to copy the link token address from the link deployment to this script. Needs PRIVATE_KEY env variable set.

node scripts/consumer.js

Funding consumer contract so that price request script next succeeds. Make sure to copy the link contract address to this script.

node scripts/fund.js

Request price from oracle

node scripts/request_price.js

Steps for the demo

For the demo, we will get the price of ONE in USDT using binance api https://api.binance.com/api/v1/ticker/price?symbol=ONEUSDT

1. Deploy oracle contract using link contract address: 0x91738e20e365abde6d48e081446917a4b5c05cb6

   • Make sure to setFulfillmentPermission by running oracle_more script with correct address (that is going to fullfill the oracle request) and the newly deployed oracle contract address.

2. Add the following job to your chainlink node using the oracle contract address from previous oracle deployment step.

{
  "initiators": [
    {
      "type": "external",
      "params": {
        "name": "harmony",
        "body": {
          "endpoint": "oracle",
          "addresses": ["<YOUR ORACLE CONTRACT ADDRESS HERE>"]
        }
      }
    }
  ],
  "tasks": [
    {
      "type": "httpget",
      "params": {
        "get": "https://api.binance.com/api/v1/ticker/price?symbol=ONEUSDT"
      }
    },
    {
      "type": "jsonparse",
      "params": { "path": ["price"] }
    },
    {
      "type": "multiply",
      "params": { "times": 100000000 }
    },
    {
      "type": "EthUint256"
    },
    {
      "type": "harmony-adapter"
    }
  ]
}

3. Send your oracle contract address and jobId so that we can include them in the aggregator deployment and invoke price feed.

Deploy an Aggregator with oracles and jobIds for aggregating the price

node scripts/aggregator.js

After deploying the aggregator, fund the aggregator contract before running price_feed.js using fund.js.

Running the price feed using the aggregator contract, add your aggregator contract to price_feed.js

node scripts/price_feed.js

Testnet Oracle Providers

Node	Oracle Contract	Job Id
SNZ Pool	0x0185b239a9d2080fd03536213413488a4b171334	cb0aa54f6b1941ca94de3c82eb5db79b
Stafi Protocol	0x702d75a957a623fb7af3cf021a7c4c4223951589	ff5dcf90d8a94e62ab9547eb9169e473
Validator Capital	0x6c6184e1b23d85ca0a13d874ede26adb1fa91cbb	db6879bf38384f5699321db973ba07a5
Chainode Tech	0x7694c1d0915ba4f921b8c06805f1f8b5154eab77	ba017f71c7ad4f2686f83190cb795a08

Testnet ONE to USDT price feed aggregator

Deployed at: 0x05d511aafc16c7c12e60a2ec4dbaf267ea72d420