Oracle Price Feeder

Setting up the oracle price feeder is necessary for validators.

Exocore relies on an external price oracle to determine the total vote power for each validator, who may be staking multiple assets. Validators are required to run a price feeder to participate in the network, which periodically fetches prices from data sources and submits them to the oracle module. Failing to run the price feeder tool may result in penalties like slashing.

Before you start, make sure to set in grpc.enable = true in app.toml, as previously advised.

There are two methods to run the price feeder tool. The first method is recommended for most validators, while the second method is suited for the more technical and risk-averse validators.

Option 1: Embedded version

1. Set up the configuration of the price feeder tool. It requires two files: the first for its own configuration and the second for the price sources.

   $HOMEDIR/config/oracle_feeder.yaml

   sources:
     chainlink
   tokens:
     - ETHUSDT
     - WSTETHUSDT
   sender:
     # either path or mnemonic must be supplied. if both are supplied,
     # mnemonic takes priority. alternatively, the mnemonic may be supplied
     # via CLI flag `--mnemonic`.
     path: "$HOMEDIR/config" # actual value not `$HOMEDIR`
     mnemonic: "your consensus mnemonic goes here"
   exocore:
     chainid: exocoretestnet_233-4
     appName: exocore
     rpc: 127.0.0.1:9090
     ws:
       addr: !!str ws://127.0.0.1:26657
       endpoint: /websocket

   The prices are sourced from Chainlink contracts on Ethereum, so you’ll need an RPC URL from providers like Alchemy and Infura or a self-hosted version.

   $HOMEDIR/config/oracle_env_chainlink.yaml

   urls:
     mainnet: !!str https://eth-mainnet.g.alchemy.com/v2/${YOUR_API_KEY}
     sepolia: !!str https://eth-sepolia.g.alchemy.com/v2/${YOUR_API_KEY}
   tokens:
     ETHUSDT: 0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419_mainnet
     WSTETHUSDT: 0xaaabb530434B0EeAAc9A42E25dbC6A22D7bE218E_sepolia

2. Run your validator as described on the next page.

Option 2: As an independent binary

This option is designed for validators who would like to decouple the two processes for security and/or reliability.

1. Download and save the price feeder tool to a location within $PATH.

   VERSION="0.1.8"
   wget -O price-feeder_${VERSION}.tar.gz "https://github.com/ExocoreNetwork/price-feeder/releases/download/v${VERSION}/price-feeder_${VERSION}_$(uname -s)_$(uname -m | sed 's/x86_64/amd64/' | sed 's/aarch64/arm64/').tar.gz"
   tar -xvzf price-feeder_${VERSION}.tar.gz
   mv bin/price-feeder /usr/bin/

2. Set up its configuration as described under Option 1 Step 1.

3. Start the price feeder tool

   price-feeder start --config $HOMEDIR/config/oracle_feeder.yaml --sources $HOMEDIR/config/

4. If everything works, productionize the process with systemd or another tool of your choice and keep it running. The expected logs are shown below.

   2024/09/11 18:02:04 Triggered, height:31, feeder-parames:{feederID:1, startBlock:20, interval:10, roundID:1}:
   2024/09/11 18:02:04 price not changed, skip submitting price for roundID:2, feederID:1