Syscoin Price Peg Server

The Syscoin Price Peg Server is a NodeJS server application for maintaining a Syscoin "Alias Peg" on the the Syscoin network's blockchain. An Alias peg provides information to the network on how many Syscoins are needed to equal 1 unit of any other currency supported by the peg.

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How it Works

The peg server uses data from multiple sources to derives the necessary values to convert values between various currencies. Fixer.io is used for all fiat currency conversion information, Coinbase is used for all BTC/USD conversion information, and a mix of Poloniex and Bittrex are used for all other blockchain currency information. The server watches each configured currency pair independently and when any one currency exchange rate moves outside the configured threshold the updated values are writted to the peg-alias on the Syscoin blockchain.

Installation and Setup (Ubuntu Linux)

Syscoin Price Peg Server installation requires NPM and Node 7+.

Note: Prior to setup make sure you have the latest versions of the required tools using the commands:

• GIT: sudo apt-get install git
• NodeJS/NPM
  • curl -sL https://deb.nodesource.com/setup_7.x | sudo -E bash -
  • sudo apt-get install -y nodejs

1. If installing from source first clone the repository using git clone https://github.com/syscoin/pricepeg.git.
2. Install the required dependencies using npm install.
3. This guide assumes you have already installed the latest Syscoin wallet and created a Syscoin.conf file with the required parameters to enable its JSONRPC server functionality.
4. The server comes with a default config.ini file which controls all aspects of the server, including which currencies it supports. For more information please refer to the configuration section.
5. Update the configuration file to reflect the Alias you with to use as a peg and the currencies you wish to support. You MUST create the peg alias on the Syscoin network with a public value of {"rates":[]} BEFORE attempting to run Price Peg Server to manage it! The wallet responsible for maintaining the peg Alias must also have a minimal balance to support transaction fees associated with the aliasupdate operation (50-100 SYS per year recommended).

Supported Currencies

The full list of supported currencies can be found in src/common.ts: supportedCurrencies or in the table at the bottom of this page.

Running the Server

The Price Peg Server must be run as a daemon. There are two optons for this:

• (Recommended) Install pm2 for better running and monitoring of the server in daemon mode.
  1. Install pm2 globall using sudo npm install -g pm2.
  2. Ensure pm2 is updated- pm2 update.
  3. Change to the Syscoin Price Peg Server directory using cd pricepeg. Run the server in daemon mode using pm2 start dist/server.js $CONFIG --name "pegserver" (may need permission).
  4. (Optional) You can now use pm2's tooling for insights on how many resources the Peg Server is using and even launch it in multiprocess or clustered mode.
• If you use the screen application you can start the server by simply running screen npm run start. Make sure to detach from the screen without terminating it!

Server Configuration

The Syscoin Price Peg Server can easily be reconfigured with zero coding knowledge. Below are the configuration properties and options. The default configuration file can also be used as a reference.

We've also included some sample configurations to further illustrate how to customize the Syscoin Price Peg Server:

• Sample Config #1 DOGE/USD Peg w/ mods
• Sample Config #2 BTC/XMR/ZEC/ETH Peg w/ mods

Property Name	Description	Default Value	Required/Optional
currencies.[CurrencySymbol]	Defines a currency to be supported by this peg server. Each currency entry should represent a seperate currency, and should define the CurrencyConfig to be used for that currency.	[ ]	required
maxUpdatesPerPeriod	Maximum number of peg updates that will be allowed to occur in a single period	6	required
updatePeriod	Duration of a single period in seconds	3600	required
updateThresholdPercentage	Percentage at which an update is attempted, if value of any peg-supported currency's exchange rate changes +/- this range vs. what is currently stored in the peg alias	0.05	required
updateInterval	Time in second to check for price change updates of a single period in seconds	300	required
pegalias	Alias on Syscoin network to update monitor and update as an alias-peg	pegtest1	required
pegalias_aliaspeg	Alias on Syscoin network specified as the aliaspeg of the peg-alias. Typically the same value as pegalias	pegtest1	required
enableLivePegUpdates	Debug mode, disables live updates to peg on network	true	optional
enablePegUpdateDebug	Debug mode, updates peg on set interval w fixed increment rather than market rates	false	optional
debugPegUpdateInterval	Debug mode, how frequently to update peg in seconds	5	optional
debugPegUpdateIncrement	Debug mode, how much to increment USD conversion	50	optional
rpcserver	Syscoin JSONRPC host server	localhost	required
rpcuser	Auth info for Syscoin JSONRPC	username	required
rpcpassword	Auth info for Syscoin JSONRPC	password	required
rpcport	Syscoin JSONRPC port	8336	optional
rpctimeout	Syscoin JSONRPC server timeout	30000	optional
httpport	Port from which the Syscoin Price Peg server will server HTTP content	8080	optional
logLevel	Should define a LogLevel to control the verbosity of the log output	logNetworkEvents=false logBlockchainEvents=true logPriceCheckEvents=true logUpdateLoggingEvents=true	optional
debugLogFilename	Name of the file that peg log output will be saved	peg.log	optional
updateLogFilename	Name of the file that the peg-update-history will be written to; this differs from debugLogFilename in that it only contains the history of the peg-alias data, so that in the case of a server stop/start the history is maintained without needing to re-query the blockchain	peg-update-history.log	optional

Currency Config

Property Name	Description	Default Value	Required/Optional
currencySymbol	Symbol used to identify this currency on exchanges- ie: USD, EUR, SYS, BTC, etc.	n/a	required
isFiat	Whether or not this currency is a fiat currency	n/a	required
dataSources	Comma-delimitted list of exchanges from which to pull exchange values from for this currency. The results will be averaged for more accurate market pricing. Valid values are "Bittrex", "Poloniex" or "Bittrex, Poloniex"	n/a	optional - only required for non-fiat currency
escrowFee	Percentage fee that arbiters will earn when their involvement is needed, specific to this currency	n/a	optional
fee	Service fee associated with Syscoin services, specific to the alias peg and currency used	n/a	optional
precision	Precision of currency conversion in decimals	n/a	required

LogLevel Config

Property Name	Description	Default Value	Required/Optional
logNetworkEvents	Should network events be written to the log- such as requests for exchange data, parsing that data, etc.	false	optional
logBlockchainEvents	Should blockchain events be written to the log- such as queiries for data from the blockchain, the results of those queries, attempts to update blockchain data, etc.	true	optional
logPriceCheckEvents	Should exchange price-check events be written to the log- comparing the current values stored in the peg alias to those being returned from the exchange data sources, if the price has changed outside the configured threshold, etc.	true	optional
logUpdateLoggingEvents	Should history-update events be written to the log- attempts to read and write from the updateLogFilename and their success/failure	true	optional

IMPORTANT NOTE: Many properties that are typically required are marked as optional in the above table because the Syscoin Price Peg server has been developed in a way to provide all required values, in the form of their default values if the operator fails to override them (with the exception of CurrencyConfig. The server also has rudimentary configuration file validation- in situations where the server fails to start please review the output in the debugLogFilename for information on what the issues are with the configuration file.

Example Config.ini

Syscoin Price Peg Server is controlled through config.ini which uses the INI configuration file format. Below are some example configurations, for more info or questions please create an issue or ask in the Syscoin Slack.

Sample Config #1 - Peg supporting DOGE and USD with modified triggers.

• Support DOGE and USD
• Use peg-alias of "doge.peg"
• Limit to 3 updates per period
• Change update period to 3 days rather than the default 1hr
• Change update threshold to 1% rather than default 5%
• Change the auth info for server

;BASIC CONFIG
;maximum number of peg updates that will be allowed to occur in a single period
maxUpdatesPerPeriod = 3

;defintion of the duration of a single period in seconds
updatePeriod = 259200

;percentage at which an update is attempted, if value of peg fluctuates +/- this range
updateThresholdPercentage = 0.01

rpcuser = secretuser
rpcpassword = secretpassword
pegalias = doge.peg
pegalias_aliaspeg = doge.peg

;MODIFY BELOW SECTION TO CHANGE CURRENCY SUPPORT
[currencies.USD]
isFiat = true
escrowFee = 0.01
precision = 2

[currencies.BTC]
isFiat = false
dataSources = Poloniex, Bittrex
escrowFee = 0.01
fee = 75
precision = 8

Sample Config #2 - Peg supporting only XMR, ZCash, BTC, and ETH with modified triggers and logging customizations

• Support XMR, ZCash, BTC, and ETH
• Use peg-alias of "multicrypto.peg"
• Change update threshold to 10% rather than default 5%
• Change the auth info for server
• Change LogLevel config
• Change log file name

;BASIC CONFIG
;percentage at which an update is attempted, if value of peg fluctuates +/- this range
updateThresholdPercentage = 0.1
debugLogFilename = mypeg.log

rpcuser = secretuser
rpcpassword = secretpassword
pegalias = multicrypto.peg
pegalias_aliaspeg = multicrypto.peg

[logLevel]
logNetworkEvents = true
logBlockchainEvents = false
logPriceCheckEvents = true
logUpdateLoggingEvents = false

;MODIFY BELOW SECTION TO CHANGE CURRENCY SUPPORT
[currencies.BTC]
isFiat = false
dataSources = Poloniex, Bittrex
escrowFee = 0.01
fee = 75
precision = 8

[currencies.XMR]
isFiat = false
dataSources = Poloniex
escrowFee = 0.05
fee = 100
precision = 8

[currencies.ZEC]
isFiat = false
dataSources = Poloniex, Bittrex
escrowFee = 0.05
fee = 75
precision = 5

[currencies.ETH]
isFiat = false
dataSources = Poloniex, Bittrex
escrowFee = 0.1
fee = 200
precision = 5

Building

Syscoin Price Peg Server is built using Typescript and ES6. Developers are encouraged to extend and enhance the native functionality, or add more currency support. Devs will need to work in the native Typescript files then transpile the code for distribution. The only command needed to rebuild code after changes is npm run build to rebuild the source and all resources to dist.

Further Development

We encourage community contributon! If you wish to contribute please issue a pull request with your changes, the team will review and merge or provide feedback. All development should happen in the /src folder. All new files should be Typescript, using ES6 JS syntax.

Full Supported Currencies List

Symbol	Name	isFiat
USD	US Dollar	true
GBP	British Pound	true
CNY	Chinese Yuan	true
EUR	Euro	true
CAD	Canada	true
AUD	Australian Dollar	true
BGN	Bulgarian Lev	true
BRL	Brazilian Real	true
CHF	Swiss Franc	true
CZK	Czech Republic Koruna	true
DKK	Danish Krone	true
HKD	Hong Kong Dollar	true
HRK	Croatian Kuna	true
HUF	Hungarian Forint	true
IDR	Indonesian Rupiah	true
ILS	Israeli New Shekel	true
INR	Indian Rupee	true
JPY	Japanese Yen	true
KRW	South Korean Won	true
MXN	Mexican Peso	true
MYR	Malaysian Ringgit	true
NOK	Norwegian Krone	true
NZD	New Zealand Dollar	true
PHP	Philippine Peso	true
PLN	Polish Zloty	true
RON	Romanian Leu	true
RUB	Russian Ruble	true
SEK	Swedish Krona	true
SGD	Singapore Dollar	true
THB	Thai Baht	true
TRY	Turkish Lira	true
ZAR	South African Rand	true
AMP	Synereo Amp	false
ARDR	Ardor	false
BBR	Boolberry	false
BTC	Bitcoin	false
BCN	Bytecoin	false
BCY	Bitcrystals	false
BELA	Bellacoin	false
BITS	Bitstar	false
BLK	Blackcoin	false
BTCD	Bitcoindark	false
BTM	Bitmark	false
BTS	Bitshares	false
BURST	Burst	false
C2	Coin2.0	false
CLAM	Clams	false
CURE	Curecoin	false
DASH	Dash	false
DCR	Decred	false
DGB	Digibyte	false
DOGE	Dogecoin	false
EMC2	Einsteinium	false
ETC	Ethereum Classic	false
ETH	Ethereum	false
EXP	Expanse	false
FCT	Factom	false
FLDC	Foldingcoin	false
FLO	Florincoin	false
GAME	Gamecredits	false
GRC	Gridcoin Research	false
HUC	Huntercoin	false
HZ	Horizon	false
IOC	IO Digital	false
LBC	LBRY Credits	false
LSK	Lisk	false
LTC	Litecoin	false
MAID	Maidsafecoin	false
MYR	Myriadcoin	false
NAUT	Nautiluscoin	false
NAV	Navcoin	false
NEOS	Neoscoin	false
NMC	Namecoin	false
NOBL	Noblecoin	false
NOTE	DNotes	false
NSR	Nushares	false
NXC	Nexium	false
NXT	NXT	false
OMNI	Omni	false
PINK	Pinkcoin	false
POT	Potcoin	false
PPC	Peercoin	false
QBK	Qibuck	false
QORA	Qora	false
QTL	Quatloo	false
RADS	Radium	false
RBY	Rubycoin	false
REP	Augur	false
RIC	Riecoin	false
SBD	Steem Dollars	false
SC	Siacoin	false
SDC	Shadow	false
SJCX	Storjcoin X	false
STEEM	Steem	false
STR	Stellar	false
STRAT	Stratis	false
SYS	Syscoin	false
UNITY	Supernet	false
VIA	Viacoin	false
WAVES	Waves	false
VOX	Voxels	false
VTC	Vertcoin	false
XBC	Bitcoinplus	false
XCP	Counterparty	false
XEM	NEM	false
XMG	Magi	false
XMR	Monero	false
XPM	Primecoin	false
XRP	Ripple	false
XVC	VCash	false
ZEC	ZCash	false