# Pegs Module Creator Tutorial

TIP

The Pegs Module is in the final stages of production.

The following tutorial is currently only compatible with computer-hardware setups that are running Linux OS's Ubuntu/Debian-based distributions.

For questions and assistance, please reach out to the Komodo team using the #cc-pegs channel on the Komodo Discord live-chat server. Thank you.

# Tutorial Overview

This tutorial assists the reader in discovering the process of creating a new Smart Chain with an active stablecoin using the Pegs Antara Module.

# Tutorial Outline

  • Launch a new test Smart Chain (CREATORUSDK) to activate the Pegs Module
  • Peg the test chain's coins to USD and create a pathway for users to back the stablecoin with KMD
  • Create tokens to represent the KMD coins
  • Create an oracle, register as a publisher, and subscribe to it
  • Create a gateway and bind the previously created token and oracle to it
  • Start the oraclefeed software to bring the blockheader data from the KMD chain to the CREATORUSDK chain through the oracle
  • Create a peg by attaching the gateway to it

Upon completion of this tutorial, the reader may follow the user tutorial and use the Smart Chain created here to discover the possibilities of the Pegs Module.

# Installation

WARNING

The following installation procedure creates a version of the Komodo software daemon that should not be used for any purpose other than testing. Several of the customizations active on this particular version of the daemon are intended for testing purposes only.

# Dependencies

Execute the following commands to install the necessary dependencies.

sudo apt-get update && sudo apt-get upgrade -y
sudo apt-get install build-essential pkg-config libc6-dev m4 g++-multilib autoconf libtool ncurses-dev unzip git python zlib1g-dev wget bsdmainutils automake libboost-all-dev libssl-dev libprotobuf-dev protobuf-compiler libgtest-dev libqt4-dev libqrencode-dev libdb++-dev ntp ntpdate software-properties-common curl clang libcurl4-gnutls-dev cmake clang libsodium-dev -y

# Create a Swap Partition (Optional)

For tutorial users using a VPS with a low amount of RAM, create a swap partition.

On the VPS, execute the following commands to create a 4GB SWAP file. (If sufficient space is available, consider creating an 8GB swap file instead, as this can facilitate better software performance.)

sudo swapon --show
free -h
df -h
sudo fallocate -l 4G /swapfile
ls -lh /swapfile
sudo chmod 600 /swapfile
ls -lh /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
sudo swapon --show
free -h
sudo cp /etc/fstab /etc/fstab.bak
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab
sudo sysctl vm.swappiness=10 # This setting will persist until the next reboot. We can set this value automatically at restart by adding the line to our /etc/sysctl.conf file:
sudo nano /etc/sysctl.conf
vm.swappiness=10

# Build the Komodo daemon

Execute the following commands to build the Komodo daemon.

git clone https://github.com/Mixa84/komodo
cd komodo
git checkout pegsCC
export CONFIGURE_FLAGS='CPPFLAGS=-DTESTMODE' # Tweaks some settings to make it easy for testing
./zcutil/fetch-params.sh
./zcutil/build.sh -j$(nproc)
cd src

This tutorial requires that the tutorial reader compile the Komodo daemon from source code. For more instructions, please see the installation section .If you have access to two VPS, follow this guide. If you want to launch this Smart Chain in your Personal Computer or using a single VPS, follow this guide

# Obtain a pubkey

Recall also that a user must have a pubkey enabled when interacting with an Antara-related Smart Chain. View this linked material for an explanation.

# Launch the Test Smart Chain

The command below creates and launches a new Smart Chain.

The following list explains a few of the Smart Chain customizations that are necessary and desirable for a Smart Chain designed for testing purposes.

  • -ac_name=CREATORUSDK — the name of this Smart Chain is set to CREATORUSDK
  • -ac_import=PEGSCC — the key customization that activated the Pegs Antara Module on the new Smart Chain
  • -ac_end=1 — sets the mining block reward to zero (after the first block)
  • -debug — a debug parameter that instructs the daemon to track various information for console output
  • -printoconsole — instructs the daemon to print the information from the debug parameter to the console
  • -ac_supply=1000000 — the amount of intial coin supply for the chain (an arbitrary amount here that includes enough coin to manage testing purposes of the chain)

Consult the Antara Customizations documentation for explanations of the other parameters in the command.

./komodod -ac_supply=1000000 -ac_reward=10000 -ac_name=CREATORUSDK -ac_cc=2 -ac_import=PEGSCC -ac_end=1 -ac_perc=0 -ac_cbopret=5 -debug=pegscc-2 -debug=importcoin -debug=cctokens -debug=gatewayscc -printtoconsole=1

# Create a Token to Represent KMD Coins

To create tokens that are capable of representing KMD (although the tokens are not yet tied to actual KMD), execute the following command on the test chain.

./komodo-cli -ac_name=CREATORUSDK tokencreate KMD 100000 "KMD_BTC,BTC_USD,*,1"

This creates a total of 100000 * 10^8 tokens named KMD on the CREATORUSDK chain. Each token is capable of representing a single satoshi of the external coin KMD.

All the tokens combined allow up to 100000 KMD coins on the CREATORUSDK chain.

The description of the token, "KMD_BTC,BTC_USD,*,1" specifies the synthetic price to be used by a peg (not yet created).

"KMD_BTC,BTC_USD,*,1" means (KMD/BTC) * (BTC/USD) * 1. This simplifies to KMD/USD, which provides an exchange price between the two currencies. This provides the necessary information to peg the CREATORUSDK stablecoin to USD and to back the coin using KMD.

The command returns a hex value as a response.

{
  "result": "success",
  "hex": "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"
}

Select the hex value (0100000001c05c55f5183a412750a...) and copy it using (CTRL + SHFT + C).

Broadcast this value using sendrawtransaction.

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex

The value of the response is called the tokenid.

0946d12135cca0757a12931944ff930657f21fd676966c12d66d5750848ea712

Copy the tokenid into a text editor and keep it available for future use.

Watch the mempool using getrawmempool to verify that the tokenid is successfully mined.

./komodo-cli -ac_name=CREATORUSDK getrawmempool

Once the tokenid disappears from the mempool the transaction is mined.

Use tokeninfo to check that the token is successfully created.

./komodo-cli -ac_name=CREATORUSDK tokeninfo 0946d12135cca0757a12931944ff930657f21fd676966c12d66d5750848ea712

The tutorial reader may now check the balance of the pubkey used to launch the daemon using tokenbalance.

./komodo-cli -ac_name=CREATORUSDK tokenbalance insert_tokenid insert_pubkey

# Create an Oracle

The Oracles Module is able to add external data to a blockchain. This modules allows the Pegs module to obtain the information needed regarding user activity and accurate prices.

When creating a new oracle, the name of the oracle is identical to the name of the tokens, KMD and the data format starts with Ihh (height, blockhash, merkleroot).

Create the oracle using oraclescreate.

./komodo-cli -ac_name=CREATORUSDK oraclescreate KMD blockheaders Ihh

The response is a hex value.

{
  "hex": "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",
  "result": "success"
}

Broadcast the returned hex value using sendrawtransaction.

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex_data

The response is a transaction id, called the oracleid.

ee684674d3671daf596395a9ca6c409381d1cf6c2c7ff05c65c6bb5c16967a0e

Record this value in the text editor.

Execute the oraclesfund method to fund the oracle.

./komodo-cli -ac_name=CREATORUSDK oraclesfund ee684674d3671daf596395a9ca6c409381d1cf6c2c7ff05c65c6bb5c16967a0e

Send the raw transaction by broadcasting the hex value.

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction 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

Response:

Optionally use the getrawmempool method to ensure that the transaction receives confirmation.

To prepare for the oraclefeed instance, use oraclesregister to register as a publisher for the oracle. This command must be executed on a node which can post KMD block headers and which can execute withdrawal transactions.

./komodo-cli -ac_name=CREATORUSDK oraclesregister insert_oracleid data_fee_in_satoshis`

This returns a hex value which must be broadcast using sendrawtransaction. (Not shown for brevity)

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex_value

Retrieve the data publisher's pubkey using oraclesinfo.

./komodo-cli -ac_name=CREATORUSDK oraclesinfo insert_oracleid

The key, "publisher", in the entry, "registered", of the returned json object is the data publisher's pubkey, also called the publisherpubkey.

Subscribe to the oracle using oraclessubscribe to receive utxo information for data publishing.

The frequency of data-publishing transactions that can be included in a block is equal to the number of active subscriptions committed to the oracle. Therefore, there must be at least one subscription for the oracle to allow publishing.

Subscribe to the oracle using the following command.

./komodo-cli -ac_name=CREATORUSDK oraclessubscribe insert_oracleid insert_publisherpubkey insert_amount_of_funds_to_add

This returns a hex value that must be broadcast using sendrawtransaction (not shown for brevity).

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex_value

In this tutorial example, the tutorial reader needs to be able to publish data more than once per block. Therefore, execute the oraclessubscribe and sendrawtransaction methods several times and with the same amount.

Verify the oracle information to ensure it is properly established.

./komodo-cli -ac_name=CREATORUSDK oraclesinfo insert_oracleid

# Bind the Token and Oracle to a Gateway

Create a gateway and bind the data from this tutorial to the gateway using the gatewaysbind method.

This method requires that tutorial reader decide how many total gateway signatures are desired (represented by the value N), and how many signatures are required to withdraw funds (represented by the value M).

For this tutorial, the reader may set both N and M equal to 1 for simplicity.

The gatewaysbind command requires that the user indicate the pubtype, p2shtype, and wiftype values for the chosen coin. For Smart Chains, these values are 60, 85 and 188 respectively.

./komodo-cli -ac_name=CREATORUSDK gatewaysbind insert_tokenid insert_oracleid KMD insert_tokensupply 1 1 insert_gatewayspubkey 60 85 188

This method returns a hex value that must be broadcast using sendrawtransaction (not shown for brevity).

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex_value

The broadcast returns a transaction id, also called the bindtxid. Copy this information to the text editor.

Assuming everything is properly created and executed, review the new gateway using gatewaysinfo.

./komodo-cli -ac_name=HELLOWORLD gatewaysinfo insert_bindtxid

Use the returned information to verify that the tokenid and oracleid match the information copied from this tutorial to the text editor.

# Start the oraclefeed software

The oraclefeed software instance automates the transfer of merkleroot data from the KMD chain to the oracle on the CREATORUSDK chain.

Change into the directory where komodod and komodo-cli are compiled.

cd  ~/komodo/src/

Compile the oraclefeed software instance.

gcc cc/dapps/oraclefeed.c -lm -o oraclefeed

Initiate the instance.

./oraclefeed CREATORUSDK insert_oracleid insert_mypubkey Ihh insert_bindtxid "cli command to access te external coin(KMD)"

Inserting the values.

./oraclefeed CREATORUSDK ee684674d3671daf596395a9ca6c409381d1cf6c2c7ff05c65c6bb5c16967a0e 02d3431950c2f0f9654217b6ce3d44468d3a9ca7255741767fdeee7c5ec6b47567 Ihh 0b5716554e523aa4678112a8ac3d15039e0aae6f4812b9d4c631cc9cfbf48786 "./komodo-cli"

# Create the Peg

Create a peg that will create CREATORUSDK coins pegged to USD and backed by KMD using the pegscreate method.

The pegscreate method is capable of creating a peg that is backed by more than one external coin. This is accomplished by adding more than one bindtxid to the pegscreate command.

Each associated gateway requires a unique token, oracle, and a running instance of the oraclefeed software, as previously described in this tutorial.

For the sake of simplicity, this tutorial utilizes only one gateway (bound to KMD coins).

./komodo-cli -ac_name=CREATORUSDK pegscreate 100000 1 0b5716554e523aa4678112a8ac3d15039e0aae6f4812b9d4c631cc9cfbf48786

This method returns a hex value that must be broadcast using sendrawtransaction (not shown for brevity).

./komodo-cli -ac_name=CREATORUSDK sendrawtransaction insert_hex_value

The broadcast returns a transaction id, also called the pegstxid. Copy this information to the text editor.

The pegstxid is the reference to the peg created in this tutorial. To make sure all the nodes running the CREATORUSDK chain are aware of the correct pegs contract, after the pegstxid transaction is mined the reader must shutdown any daemons running the chain. The tutorial reader then restarts the nodes, but with a slightly modified version of the launch parameters. The parameters now include -earlytxid, and this parameter is set equal to the value of pegstxid.

In the following command, replace the text <pegstxid> with the pegstxid from this tutorial.

./komodod -ac_supply=1000000 -ac_reward=10000 -ac_name=CREATORUSDK -ac_cc=2 -ac_import=PEGSCC -ac_end=1 -ac_perc=0 -ac_cbopret=5 -debug=pegscc-2 -debug=importcoin -debug=cctokens -debug=gatewayscc -printtoconsole=1 -earkytxid=<pegstxid>

Note

For any Smart Chain, the -earlytxid must be added to the launch parameters before the chain reaches a total block height of 100. The tutorial reader may control the pace of mining on a Smart Chain with the commands ./komodo-cli setgenerate true 1 (starting) and ./komodo-cli setgenerate false (stopping).

Any new node joining the CREATORUSDK network must use the new launch parameters with the -earlytxid included.

# Test the Setup

Follow the Pegs Module Tutorial - User documentation to continue learning about the Pegs Antara Module.