price-feeder

Oracle Price Feeder

This is a standalone version of Umee's fantastic work and integrating it more closely with the Cosmos SDK.

Changes

• exchange_rates when broadcasting votes has been reverted to the Cosmos SDK denom string, as is used in Se's Oracle module
• config.toml supports an account.prefix property, to provide compatibility across multiple networks

Setup

If a cluster is running Oracle price-feeder, your validator is also required to run a price feeder or your validator will be jailed for missing votes.

Create an account for Oracle Price Feeder Delegate

1. To avoid account sequence errors with the admin account, it's reccomended to create a different account as an Oracle delegate. To do so, you'll need to create the account with seid keys add price-feeder-delegate or any other account name. This may still cause account sequence errors for the delegate account but since it's only being used for the Oracle price feeder, it's not a concern
2. With the account address output, export PRICE_FEEDER_DELEGATE_ADDR=<output>
3. seid tx oracle set-feeder $PRICE_FEEDER_DELEGATE_ADDR --from <validator-wallet> --fees 2000usei -b block -y --chain-id {chain-id}
4. Make sure to send bank a tiny amount to the account in order for the account to be created seid tx bank send [VALIDATOR_ACCOUNT] $PRICE_FEEDER_DELEGATE_ADDR --from [VALIDATOR_ACCOUNT] [AMOUNT] --fees=2000usei -b block -y

Then you need to export PRICE_FEEDER_PASS environment variable to set up the keyring password. That was entered during the account setup.

Ex : export PRICE_FEEDER_PASS=keyringPassword

If this environment variable is not set, the price feeder will prompt the user for input.

Setup Healthchecks

Add this to the config.toml, you need to add the timeout field as it's required

[[healthchecks]]
url = "https://hc-ping.com/xxxxxx"
timeout = "5s"

Make and install the binary

From the root of the Git repo

make install-price-feeder

Run Price Feeder

You can run it as a seperate binary but it's reccomedned to run it as a systemd serivce, you can use the following as an example.

You need to setup a config.toml file (see this for example), you need to set the following fields in

...
[account]
address = "<UPDATE ME>"  <-- $PRICE_FEEDER_DELEGATE_ADDR from above
chain_id = "<UPDATE ME>"
validator = "<UPDATE ME>" <-- validator address
...

Systemd Configuration

In order to run the price feeder as a background process, you can set up a systemd service for it. Here is an example of the service that will run the price feeder process. Then you just need to run systemctl enable <service-name> and systemctl start <service-name>

[Unit]
Description=Oracle Price **Feeder**
After=network.target

[Service]
User=root
Type=simple
Environment="PRICE_FEEDER_PASS={KEYRING_PASSWORD}"
ExecStart=/root/go/bin/price-feeder {PATH-TO-CONFIG-TOML}
Restart=on-failure
LimitNOFILE=6553500

[Install]
WantedBy=multi-user.target

Providers

The list of current supported providers:

• Binance
• MEXC
• Coinbase
• Gate
• Huobi
• Kraken
• Okx

Usage

The price-feeder tool runs off of a single configuration file. This configuration file defines what exchange rates to fetch and what providers to get them from. In addition, it defines the oracle's keyring and feeder account information. The keyring's password is defined via environment variables or user input. More information on the keyring can be found here Please see the example configuration for more details.

$ price-feeder /path/to/price_feeder_config.toml

Configuration

telemetry

A set of options for the application's telemetry, which is disabled by default. An in-memory sink is the default, but Prometheus is also supported. We use the cosmos sdk telemetry package.

deviation

Deviation allows validators to set a custom amount of standard deviations around the median which is helpful if any providers become faulty. It should be noted that the default for this option is 1 standard deviation.

provider_endpoints

The provider_endpoints option enables validators to setup their own API endpoints for a given provider.

server

The server section contains configuration pertaining to the API served by the price-feeder process such the listening address and various HTTP timeouts.

currency_pairs

The currency_pairs sections contains one or more exchange rates along with the providers from which to get market data from. It is important to note that the providers supplied in each currency_pairs must support the given exchange rate.

For example, to get multiple price points on ATOM, you could define currency_pairs as follows:

[[currency_pairs]]
base = "ATOM"
providers = [
  "binance",
]
quote = "USDT"

[[currency_pairs]]
base = "ATOM"
providers = [
  "kraken",
]
quote = "USD"

Providing multiple providers is beneficial in case any provider fails to return market data. Prices per exchange rate are submitted on-chain via pre-vote and vote messages using a time-weighted average price (TVWAP).

account

The account section contains the oracle's feeder and validator account information. These are used to sign and populate data in pre-vote and vote oracle messages.

keyring

The keyring section contains Keyring related material used to fetch the key pair associated with the oracle account that signs pre-vote and vote oracle messages.

rpc

The rpc section contains the Tendermint and Cosmos application gRPC endpoints. These endpoints are used to query for on-chain data that pertain to oracle functionality and for broadcasting signed pre-vote and vote oracle messages.

healthchecks

The healthchecks section defines optional healthcheck endpoints to ping on successful oracle votes. This provides a simple alerting solution which can integrate with a service like healthchecks.io. It's recommended to configure additional monitoring since third-party services can be unreliable.

Keyring

Our keyring must be set up to sign transactions before running the price feeder. Additional info on the different keyring modes is available here. Please note that the test and memory modes are only for testing purposes. Do not use these modes for running the price feeder against mainnet.