Integrate Tellor on a New Chain

Follow these steps to provide tellor data on a new evm chain

In this guide, we will go through the steps of providing access to tellor data on a new chain. You do not have to perform these steps yourself, and the tellor team would be happy to help if you contact us on Discord or this google form.

For those with a do-it-yourself attitude, this guide will involve:

• deploying the TellorDataBridge contract

• deploying an example user contact SimpleLayerUser

• installing the relayer

• running the relayer

Following the steps in this guide does not guarantee access to absolutely secure oracle data. See the Tellor Security 201 article for more information.

Clone Tellor and Install

First, clone tellor layer:

git clone https://github.com/tellor-io/layer.git

Move to the evm directory:

cd layer/evm

Install the tellor hardhat project:

npm i

Deploy Contracts

Create an env file:

cp .env.example .env

Open your new .env file and add your ethereum private key and an rpc node url.

Open the hardhat.config.js file and add your evm chain information under networks. You can use the sepolia section as a guide.

TellorDataBridge

Now we're going to use deployment scripts to deploy the TellorDataBridge contract. This is the contract responsible for verifying that relayed data is authentic tellor data.

Open the deployment script ./scripts/DeployTellorDataBridge.js. At the top of the file, you will see a variable guardianaddress. You will need to choose an address who is responsible for resetting the TellorDataBridge validator set in the event that it becomes stale (no updates within 21 days). As long as the validator set is always kept up to date in the contract, the guardian will have no special privileges or responsibilities.

Set the address to one of your own addresses:

var guardianaddress = "0xYOUR_ADDRESS"

You should also update the PK and NODE_URL variables to match those in your .env file.

Now you should be able to deploy the TellorDataBridge contract:

npx hardhat run scripts/DeployTellorDataBridge.js --network YOUR_NETWORK

The following should print in your logs:

deploy TellorDataBridge
TellorDataBridge deployed to: 0xYOUR_DATA_BRIDGE_ADDRESS

We will use the address 0xYOUR_DATA_BRIDGE_ADDRESS in the steps below.

SimpleLayerUser

Now we will deploy the SimpleLayerUser contract as an example oracle user.

Open the deployment script ./scripts/DeploySimpleLayerUser.js. Set the TellorDataBridge address

var dataBridgeAddress = "0xYOUR_DATA_BRIDGE_ADDRESS"

You will also need a queryId. We will use the ETH/USD spot price queryId in this example.

var queryId = "0x83a7f3d48786ac2667503a61e8c415438ed2922eb86a2906e4ee66d9a2ce4992"

Update the PK and NODE_URL variables to match those in your .env file.

Now we are ready to deploy the SimpleLayerUser:

npx hardhat run scripts/DeploySimpleLayerUser.js --network YOUR_NETWORK

This will print in your logs:

deploying SimpleLayerUser
SimpleLayerUser deployed to: 0xYOUR_TELLOR_USER_ADDRESS

We will use 0xYOUR_TELLOR_USER_ADDRESS when running the relayer below.

Setup and Run the Relayer

The relayer is used to get oracle data from tellor and submit it to your user contract.

Follow the setup instructions for the relayer. We recommend you set your ETH_PRIVATE_KEY in the relayer .env file, using the same evm address you used to deploy the contracts in the steps above. Only the deployer address can initialize the TellorDataBridge contract, but any address can run the relayer after initialization. You should also set the WEB3_PROVIDER_URL.

Initialize TellorDataBridge

We need to initialize the TellorDataBridge contract with the current tellor validator set information.

relayer init --data-bridge-address 0xYOUR_DATA_BRIDGE_ADDRESS

Now you should be ready to relay data to your contract.

Relay Data

relayer relay --layer-user-address 0xYOUR_TELLOR_USER_ADDRESS --data-bridge-address 0xYOUR_DATA_BRIDGE_ADDRESS --contract-type SimpleLayerUser --sleep-time 3600

The relayer should gather tellor oracle data and submit it to your contract. If you see a transaction hash printed in the relayer logs, that's a good sign. Check your evm chain's block explorer to see whether you relayed data successfully.

Given the sleep-time argument we entered in that last command, the relayer will continuously submit new oracle data once every hour. You may also see the relayer update the validator set in the TellorDataBridge contract occasionally.