Overview

For upwards of 2 years, Tellor has been live on Ethereum mainnet. In an effort to facilitate a multi-chain ecosystem, the Tellor oracle has been re-implemented for the Algorand Virtual Machine (AVM). On Algorand, Tellor continues to be secure, decentralized, and easy to integrate.

The primary contracts of the Tellor oracle on Algorand are the feed contracts, the medianzier contracts, and the governance contract. At a high level, each price feed, or “queryId”, uses a “medianizer contract” to calculate the median between 5 independent data submissions on 5 independent “feed contracts”. Tellor on Algorand implements a vigilant governance contract that prevents bad actors from interfering with the security of price feeds.

In short, Tellor on Algorand is a secure, decentralized, and easy-to-use re-implementation of Tellor on Ethereum for the Algorand network. Tellor on Algorand serves to broaden the Tellor network and extend the Algorand ecosystem. This repo supplies the core contracts in PyTeal, contract interaction CLI scripts in python, and thorough testing in Pytest.

For more in-depth information about Tellor checkout our documentation, whitepaper and website.

This repo comes with...

Ready-to-go price feeds

This repo comes equipped with ready-to-go price feeds. This means reporting values from these feeds via the CLI requires no configuration beyond providing accounts. These are the most commonly used data feeds in DeFi (BTCUSD, ETHUSD, etc.). These feeds are listed under feeds in the config.yml file.

Open-source contract interaction

Just like on Ethereum, all Tellor contracts on Alogrand are open-source, freely available, and very forkable. Open-source deployment, testing, and contract interaction scripts in Python are supplied in the repo. These scripts can be called via the command line (very useful for github actions!), or via further python scripting. For CLI examples, see below.

Setting up, interacting with, and testing the contract

An example walkthrough using the BTCUSD feed on testnet

Prerequisites:

• Install docker + docker-compose (on mac and windows, Docker Desktop)
• Fund a reporter account with a minimum of 200 ALGO for staking (for mainnet and testnet)
• Fund a deployment account with 16 ALGO to test (this account will be used for deploying a medianizer and 5 data feed contracts). Algorand addresses have to be funded with a minimum of 15 ALGO but additional is needed to deploy and transact.

1. Run docker and leave it running

2. Create .env file

This sets up accounts to be used securely since the .env file is not pushed to github. You can use the .env.example as an example.

• Create a file called .env
• Copy and paste the variable names from the .env.example file and add your mnemonics to the .env file
• Save the .env file

note: Algorand private keys are mnemonics, not hex strings!

REPORTER_MNEMONIC="<your reporter account mnemonic>"
TIPPER_MNEMONIC="<your tipper account mnemonic>"
MEMBER_1="<the first multisig account's mnemonic>"
MEMBER_2="<the second multisig account's mnemonic>"

3. Open two terminals

One will be used to run and Algorand sanbox node and the other one will run the python commands/environment.

4. Run an Algorand sandbox in one terminal

git clone https://github.com/algorand/sandbox.git
cd sandbox
./sandbox up

5. Set up python environment on the second terminal and install dependencies

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

6. Test repo locally

python -m pytest

7. Deploy medianizer and price feed contracts

This script deploys the medianizer app and five BTCUSD data feeds from the deployment account you set up on the prerequisites section.

• Update the governance_address in the config.yml file to be the deployment address you created and funded on the prerequesites section.

python -m src.scripts.deploy -qid BTCUSD -qd "btc/usd spot price ticker" -tf 120 -n testnet

notes:
- available networks:
    - devnet
    - testnet
    - mainnet
- setting timestamp freshness to 120 reverts reports of data older than 2 minutes

• Update the application ids from terminal into config.yml for the medianizer and feeds (replace the entire array for the feeds).

feeds:
  BTCUSD:
    app_ids:
      medianizer:
        testnet: #put medianizer app id here!
      feeds:
        testnet: [] #put feed app ids in array here!

8. Stake account (become data reporter) on one of five feed apps

note: fid indicates the choice of feed app (choose 1-5) since 5 feed apps were deployed. For testing we are using the first app below.

python -m src.scripts.stake -qid BTCUSD -fid 1 -n testnet

9. Report (submit value) BTCUSD price to contract

python -m src.scripts.report -qid BTCUSD -fid 1 -n testnet

Current Price feeds

These are the current feeds avialable on Algorand. For additional feeds please submit an issue in this repo.

Mainnet price feeds

Contract	DataFeed	Algo Ap
Medianizer	BTC/USD	https://algoexplorer.io/application/733871808
TellorFlex	BTC/USD	https://algoexplorer.io/application/733870916
TellorFlex	BTC/USD	https://algoexplorer.io/application/733871155
TellorFlex	BTC/USD	https://algoexplorer.io/application/733871343
TellorFlex	BTC/USD	https://algoexplorer.io/application/733871516
TellorFlex	BTC/USD	https://algoexplorer.io/application/733871647

Testnet price feeds

Contract	DataFeed	Algo Ap
Medianizer	BTC/USD
TellorFlex	BTC/USD
TellorFlex	BTC/USD
TellorFlex	BTC/USD
TellorFlex	BTC/USD
TellorFlex	BTC/USD

Maintainers

This repository is maintained by the Tellor team

How to Contribute

Join our Discord:

Check out our issues log here on Github or feel free to reach out anytime [email protected]

Copyright

Tellor Inc. 2022