Setzer

Publish signed prices to an Ethereum oracle.

Commands

Usage: setzer [<opts>] <command> [<args>]
   or: setzer <command> --help

Commands:

   broadcast       Broadcast signed prices over ssb
   deploy          Deploy a new oracle contract
   help            Print help about setzer or one of its subcommands
   latest          Print most recent quorum price messages for a pair
   pairs           List all supported price pairs
   poke            Poke an on-chain oracle with latest prices
   price           Fetch exchange price(s) for a given asset or pair
   sources         Show price sources for a given asset or pair
   test            Test all price sources

Basic usage

setzer deploy [--quorum] <pair>

• Deploys the MakerDAO medianizer contract with the toll modifier removed to allow anyone to read prices from the oracle.
• The initial quorum (bar) required to push new prices to the contract is set to 1 by default or --quorum=<number> if provided.

setzer broadcast [--interval] [<pair>]

• Continuously broadcasts prices over the setzer ssb network at a given interval.
• Prices are signed with an Ethereum key, allowing message authenticity to be verified.
• pair can be singular e.g ethusd or a space-separated list of pairs. If no pairs are specified, all setzer pairs will be used.
• pair is assumed to ba a USD pair and can be upper or lowercase, with or without quote appended e.g ETH or ETHUSD.

setzer poke <address>

• Pokes an on-chain oracle at a given address.
• Retrieves the pair, quorum, and age from the oracle and queries the ssb network for valid price data. If sufficient fresh price data is available from feeds trusted by the oracle, a poke transaction is submitted to update the on-chain price.

Price sources

List price sources for any given pair with sources

$ setzer sources btcusd
binance
bitfinex
bitstamp
coinbase
gemini
kraken
upbit

Specify the source to get a price from a particular exchange. Without a source all sources are queried and the median is returned. Broadcast publishes the median price.

$ setzer price btc binance
10368.1388898810

$ setzer price btc
10304.4800000000

Demo

# Start an Ethereum testnet
$ dapp testnet

# In a new shell
$ export ETH_RPC_URL=http://127.0.0.1:8545
$ export ETH_KEYSTORE=$HOME/.dapp/testnet/8545/keystore
$ export ETH_PASSWORD=/dev/null
$ export ETH_FROM=$(seth accounts ls | sed 1q | awk '{print substr ($0, 0, 42)}')

# Deploy an oracle to testnet and trust the deployer
$ ORACLE=$(setzer deploy ETHUSD --quorum 1)
$ seth send $ORACLE 'lift(address)' $ETH_FROM

# Broadcast signed prices
$ setzer broadcast ETHUSD --interval 120
2019-09-16 07:44:03 ETHUSD 188.9850000000
2019-09-16 07:46:15 ETHUSD 188.9541217800
2019-09-16 07:48:28 ETHUSD 188.9662400800
2019-09-16 07:50:41 ETHUSD 189.4291848000
2019-09-16 07:52:55 ETHUSD 189.3350000000
2019-09-16 07:55:06 ETHUSD 189.4150000000
2019-09-16 07:57:21 ETHUSD 189.5800000000

# Update the testnet oracle with latest prices
$ setzer poke $ORACLE
seth send 0x6816ae807feFbBe49e80331C069Ae4BA7Dd6be3b 'poke(uint256[] memory,uint256[] memory,uint8[] memory,bytes32[] memory,bytes32[] memory)' '[00000000000000000000000000000000000000000000000a1ddf6d3eaf660000]' '[000000000000000000000000000000000000000000000000000000005d7db476]' '[000000000000000000000000000000000000000000000000000000000000001c]' '[e129727276e098cc91e069f6682ae55378255ef5e69733b984007e0fa5a1c415]' '[2d8316fca04337037fa723788603c87ab8c25bce8d8809b79614a14e0a207f6f]'
seth-send: Published transaction with 484 bytes of calldata.
seth-send: Waiting for transaction receipt...
seth-send: Transaction included in block 81.

Not (yet) handled

• Price signer governance
• Staking, Rewards
• ssb invites

Installation

Dependencies:

• GNU bc
• curl
• dapp
• GNU datamash
• GNU date
• jshon
• Jq
• GNU timeout
• seth
• ssb

Install via make:

• make link - link setzer into /usr/local
• make install - copy setzer into /usr/local
• make uninstall - remove setzer from /usr/local

Configuration

• SETZER_DIR - Tmp cache directory (default: ~/.setzer)
• SETZER_CACHE_EXPIRY - Price fetch cache expiry (default: 60) sec.
• SETZER_TIMEOUT - HTTP request timeout (default: 10) sec.
• SETZER_BROADCAST_INTERVAL Price broadcast interval (default: 120) 2 min.
• SETZER_QUORUM Min. signed prices required to update an oracle

Todo

• Specify asset pairs via config file
• Nix | dapp.tools install
• Remove jshon