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hardhat-reef-examples shows the use of hardhat-reef plugin to interact with the Reef chain.


Install dependencies with yarn.


Define your Reef chain URL in hardhat.config.js (by default ws://

module.exports = {
  solidity: "0.7.3",
  defaultNetwork: "reef",
  networks: {
    reef: {
      url: "ws://",
    reef_testnet: {
      url: "wss://",
      scanUrl: "", // Localhost verification testing: http://localhost:3000
      seeds: {
        testnet_account: "<MNEMONIC_SEED>",
    reef_mainnet: {
      url: "wss://",
      scanUrl: "wss://",
      seeds: {
        mainnet_account: "<MNEMONIC_SEED>",

Copy .env.example to .env (cp .env.example .env) and update the desired mnemonic variable to your account seed mnemonic for the corresponding network.

You can have multiple accounts by listing them in dictionary with your custom name:

seeds: {
	account1: "<MNEMONIC_SEED1>",
	account2: "<MNEMONIC_SEED2>",

In JS script you can select the account with:

const reef = await hre.reef.getSignerByName("account1");

where account1 is the key of the item in the seeds dictionary.

If you get the following error:

Invalid Transaction: Inability to pay some fees , e.g. account balance too low

it is most likely because the accounts defined in the hardhat.config.js and JS script do not match.


See scripts/ folder for example scripts, e.g. to deploy flipper run:

yarn hardhat run scripts/flipper/deploy.js 

After the contract is deployed, you can interact with it using the flip.js script:

yarn hardhat run scripts/flipper/flip.js 

make sure the flipperAddress corresponds to the deployed address.

Deploy and verify Token contract:

yarn hardhat run scripts/erc20/deploy_and_verify.js --network reef_testnet

Integration localhost tests with reef-explorer

yarn hardhat run scripts/integration-test.js

Deploying on testnet

The above commands will deploy on development (local) network by default. To deploy on testnet, use the --network flag:

yarn hardhat run scripts/flipper/deploy.js --network reef_testnet 

To get initial REEF tokens on the testnet, visit dev Matrix chat and use the following command: