How to Set Up Tellor as your Oracle

solidity

smart contracts

price feeds

oracles

beginner

️Tellor

Tellor Docs

June 29, 2021

1 minute read

Pop Quiz: Your protocol is just about finished, but it needs an oracle to plug in to get an active off chain data feed going...What do you do?

(Soft) Prerequisites

This post aims to make accessing an oracle feed as simple and straightforward as possible. That said, we're assuming the following about your coding skill-level to focus on the oracle aspect.

Assumptions:

• you can navigate a terminal
• you have npm installed
• you know how to use npm to manage dependencies

Tellor is a live and open-sourced oracle ready for implementation. This beginner's guide is here to showcase the ease with which one can get up and running with Tellor, providing your project with a fully decentralized and censorship-resistent oracle.

Overview

Tellor is an oracle system where parties can request the value of an off-chain data point (e.g. BTC/USD) and miners compete to add this value to an on-chain data-bank, accessible by all Ethereum smart contracts. The inputs to this data-bank are secured by a network of staked miners. Tellor utilizes cryptoeconomic incentive mechanisms, rewarding honest data submissions by miners and punishing bad actors through the issuance of Tellor’s token, Tributes (TRB) and a dispute mechanism.

In this tutorial we'll go over:

• Setting up the initial toolkit you'll need to get up and running.
• Walk through a simple example.
• List out testnet addresses of networks you currently can test Tellor on.

UsingTellor

The first thing you'll want to do is install the basic tools necessary for using Tellor as your oracle. Use this package to install the Tellor User Contracts to test the implementation of Tellor in your contracts:

npm install usingtellor

Once installed this will allow your contracts to inherit the functions from the contract 'UsingTellor'.

Great! Now that you've got the tools ready, let's go through a simple exercise where we request the bitcoin price:

BTC/USD Example

Inherit the UsingTellor contract, passing the Tellor address as a constructor argument:

Here's an example

1import "usingtellor/contracts/UsingTellor.sol";
2
3contract BtcPriceContract is UsingTellor {
4
5  //This contract now has access to all functions in UsingTellor
6
7  uint256 btcPrice;
8  uint256 btcRequestId = 2;
9
10  // Input Tellor oracle address. See below for available addresses or
11  // deploy the TellorPlayground yourself
12  constructor(address payable _tellorAddress) UsingTellor(_tellorAddress) {}
13
14  function setBtcPrice() public {
15    bool _didGet;
16    uint _timestamp;
17
18    (_didGet, btcPrice, _timestamp) = getCurrentValue(btcRequestId);
19  }
20}
21
22
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Want to try a different price feed? Check out the list of supported prices here: Current Data Feeds

Looking to do some testing first? See the list below for our active testnet addresses:

Addresses:

Mainnet: 0x88df592f8eb5d7bd38bfef7deb0fbc02cf3778a0

Rinkeby: 0x88df592f8eb5d7bd38bfef7deb0fbc02cf3778a0

Kovan: 0x20374E579832859f180536A69093A126Db1c8aE9

Ropsten: 0x20374E579832859f180536A69093A126Db1c8aE9

Goerli: 0x20374E579832859f180536A69093A126Db1c8aE9

The following networks use the 'Fellowship' instead of the POW miners:

BSC Testnet: 0xbc2f9E092ac5CED686440E5062D11D6543202B24

Polygon Mumbai Testnet: 0xbc2f9E092ac5CED686440E5062D11D6543202B24

For a more robust implementation of the Tellor oracle, check out the full list of available functions here.

Last edit: , Invalid DateTime

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