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Setup Test Net validator node from scratch on Ubuntu 20.04


By choosing to participate in the Casper Test Net, you acknowledge that you have reviewed and will abide by the Test Net Code of Conduct and Incentive Requirements. Failure to do so may reduce or fully disqualify any Test Net incentive participation.

Before you set up your node, make sure it conforms to the minimum Recommended Hardware Specifications


Do not execute all the commands below as root. sudo is included where it is required.

Do not create or use the username casper. It will be automatically created during the installation, and is meant to be used by the node software as a no-login user.

Expect that initial setup of a node will take about 15-20 minutes, and you will need to wait for a few hours for the node to sync before bonding it to the network.

Open Firewall Ports

In your firewall set-up, make sure you expose the following ports to public and that they’re routed to your node:

Update Open Files Limit

Before beginning, update the maximum open files limit for your system. Specifically, update the node’s /etc/security/limits.conf file as described below, to ensure proper node operation.

Add the following row to the bottom of the /etc/security/limits.conf file:

casper          hard    nofile          64000

And make sure the bottom part of the file contents looks similar to what is seen below:

#*               soft    core            0
#root            hard    core            100000
#*               hard    rss             10000
#@student        hard    nproc           20
#@faculty        soft    nproc           20
#@faculty        hard    nproc           50
#ftp             hard    nproc           0
#ftp             -       chroot          /ftp
#@student        -       maxlogins       4
casper          hard    nofile          64000

# End of file

Install software

Update package repositories

sudo apt update

Install pre-requisites

sudo apt install -y dnsutils software-properties-common git

The node uses dig to get external IP for autoconfig during the installation process

Install helpers

sudo apt install jq -y

We will use jq to process JSON responses from API later in the process

Remove Previous Versions

If you were running previous versions of the casper-node on this machine, first stop and remove the old versions:

sudo systemctl stop casper-node-launcher.service
sudo apt purge -y casper-client
sudo apt purge -y casper-node-launcher
sudo rm -rf /etc/casper
sudo rm -rf /var/lib/casper

Install Casper node

Add Casper repository

Execute the following in order to add the Casper repository to apt in Ubuntu.

echo "deb [arch=amd64]" focal main | sudo tee -a /etc/apt/sources.list.d/casper.list
curl -O
sudo apt-key add casper-repo-pubkey.asc
sudo apt update

Install the Casper node software

sudo apt install -y casper-client casper-node-launcher

Build smart contracts that are required to bond to the network

Install pre-requisites for building smart contracts

cd ~
sudo apt purge --auto-remove cmake
wget -O - 2>/dev/null | gpg --dearmor - | sudo tee /etc/apt/trusted.gpg.d/kitware.gpg >/dev/null
sudo apt-add-repository 'deb focal main'   
sudo apt update
sudo apt install cmake -y

curl --proto '=https' --tlsv1.2 -sSf | sh

sudo apt install libssl-dev -y
sudo apt install pkg-config -y
sudo apt install build-essential -y

BRANCH="1.0.20" \
    && git clone --branch ${BRANCH} "wabt-${BRANCH}" \
    && cd "wabt-${BRANCH}" \
    && git submodule update --init \
    && cd - \
    && cmake -S "wabt-${BRANCH}" -B "wabt-${BRANCH}/build" \
    && cmake --build "wabt-${BRANCH}/build" --parallel 8 \
    && sudo cmake --install "wabt-${BRANCH}/build" --prefix /usr --strip -v \
    && rm -rf "wabt-${BRANCH}"

Build smart contracts

Pull sources

Go to your home directory and clone the node repository. Later we will use this path to the smart contracts in our bonding request.

cd ~

git clone
cd casper-node/

Checkout the release branch

Verify that the version of your contracts matches the version of the casper-node software you have installed.

git checkout release-1.5.2

Build the contracts

make setup-rs
make build-client-contracts -j

Generate keys and fund your account

Generate node keys

Navigate to the default key directory:

cd /etc/casper/validator_keys

And execute the following command to generate the keys:

sudo -u casper casper-client keygen .

It will create three files in the /etc/casper/validator_keys directory:

Save your keys to a safe place. The public key hex file is used to identify your account when delegators stake their tokens with you or if you are transferring CSPR to this account.

Create account

Install Casper Wallet, and import your secret_key.pem file following the steps described under the Import keys into Casper Wallet section of the Migrating to Casper Wallet from Signer guide.

Fund account

Go to Testnet CSPR.Live, and connect with the account you want to fund. Click Tools from the top navigation menu, then click Faucet. Wait for the faucet page to load, and click the Request tokens button. Wait until the request transaction succeeds.

Configure and Run the Node

Configure the node’s firewall

In order to secure your node somewhat from unauthorized/excessive connections/requests, you can configure the firewall of the node using a template ufw setup:

cd ~; curl -JLO
chmod +x ./

# Look at this and make sure you understand what it does and want to run it on your server.
# You will need to provide `y` to reset and enable steps.
cat ./

# Install firewall
sudo ./

Stage all protocol upgrades

sudo -u casper /etc/casper/ stage_protocols casper-test.conf

The above command will download and stage all available node upgrades to your machine so they are prepped when the node is turned on, and will automatically execute the upgrade and the required time.

Set trusted hash

Set the trusted_hash to the hash value of the latest block on Casper TestNet:

sudo sed -i "/trusted_hash =/c\trusted_hash = '$(casper-client get-block --node-address $NODE_ADDR | jq -r .result.block.hash | tr -d '\n')'" /etc/casper/$PROTOCOL/config.toml

The command above will set the trusted hash on the config file of the 1.5.2 protocol version. Please note that the protocol version should be set to the largest available protocol version you see in ls /etc/casper.

Start the node

sudo logrotate -f /etc/logrotate.d/casper-node
sudo systemctl start casper-node-launcher; sleep 2
systemctl status casper-node-launcher

Monitor the node status

Check the node log

Please note that it is expected to see a lot of connection messages flooding your screen when you check the logs. Don’t be scared by the request timed out and outgoing connection failed messages as long as they are all INFO level messages, and as long as you also see a lot of linear chain block stored messages, which means that your node is successfully fetching and storing existing blocks from other/older peers on the network.

sudo tail -fn100 /var/log/casper/casper-node.log /var/log/casper/casper-node.stderr.log

Check the node status

curl -s | jq

Monitor the node’s sync progres

You can monitor the node’s synchronization progress by using the utility script:

/etc/casper/ watch

When you run the watch command, expect to see something like this:

Every 5.0s: /etc/casper/ node_status ; /etc/casper/ systemd_status

Last Block: 2035316 (Era: 10565)
Peer Count: 214
Uptime: 1day 20h 31m 7s 504ms
Build: 1.5.2-86b7013
Key: 0173a3611a3730d6d1a71e91c15a046b3278f6ae9291df6963067958d87035e1fc
Next Upgrade: None

Reactor State: KeepUp
Available Block Range - Low: 2028872  High: 2035316

● casper-node-launcher.service - Casper Node Launcher
     Loaded: loaded (/lib/systemd/system/casper-node-launcher.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2023-09-08 22:15:57 UTC; 1 day 20h ago
   Main PID: 2775 (casper-node-lau)
      Tasks: 11 (limit: 38291)
     Memory: 29.3G
     CGroup: /system.slice/casper-node-launcher.service
             ├─2775 /usr/bin/casper-node-launcher
             └─2789 /var/lib/casper/bin/1_5_2/casper-node validator /etc/casper/1_5_2/config.toml

If your Reactor State is in “CatchUp” you will need to wait for the node to gather more blocks before it will become “KeepUp” and subsequently show an “Available Block Range”.

If your casper-node-launcher status is not active (running) with increasing time, you are either not running or restarting.

The watch command also allows an --ip argument to use with a node on the same network that is in sync. This will show how far behind your node currently is.

Wait for node to catch up

Before you do anything, such as trying to bond as a validator or perform any RPC calls, make sure your node has fully caught up with the network. You can recognize this by log entries that tell you that joining has finished, and that the RPC and REST servers have started:

{"timestamp":"Feb 09 02:28:35.577","level":"INFO","fields":{"message":"finished joining"},"target":"casper_node::cli"}
{"timestamp":"Feb 09 02:28:35.578","level":"INFO","fields":{"message":"started JSON-RPC server","address":""},"target":"casper_node::components::rpc_server::http_server"}
{"timestamp":"Feb 09 02:28:35.578","level":"INFO","fields":{"message":"started REST server","address":""},"target":"casper_node::components::rest_server::http_server"}

While Monitoring the node’s synchronization progress using the utility script:

/etc/casper/ watch

Make sure the Node is in KeepUp and has synced enough blocks for the current TTL (2 hours / 16.384 = 450 blocks) before continuing with the next steps.

Bond to the network

Once you ensure that your node is running correctly and is visible by other proceed to bonding.

Check your balance

Check your balance to ensure you have funds to bond:

If you followed the installation steps from this document you can run the following script to check the balance:

PUBLIC_KEY_HEX=$(sudo -u casper cat /etc/casper/validator_keys/public_key_hex)
STATE_ROOT_HASH=$(casper-client get-state-root-hash --node-address | jq -r '.result | .state_root_hash')
PURSE_UREF=$(sudo -u casper casper-client query-state --node-address --key "$PUBLIC_KEY_HEX" --state-root-hash "$STATE_ROOT_HASH" | jq -r '.result | .stored_value | .Account | .main_purse')
casper-client get-balance --node-address --purse-uref "$PURSE_UREF" --state-root-hash "$STATE_ROOT_HASH" | jq -r '.result | .balance_value'

Make bonding request

If you followed the installation steps from this document you can run the following script to bond. It substitutes the public key hex value for you and sends recommended argument values:

PUBLIC_KEY_HEX=$(sudo -u casper cat /etc/casper/validator_keys/public_key_hex)
CHAIN_NAME=$(curl -s | jq -r '.chainspec_name')

sudo -u casper casper-client put-deploy \
    --chain-name "$CHAIN_NAME" \
    --node-address "" \
    --secret-key "/etc/casper/validator_keys/secret_key.pem" \
    --session-path "$HOME/casper-node/target/wasm32-unknown-unknown/release/add_bid.wasm" \
    --payment-amount 3000000000 \
    --session-arg=public_key:"public_key='$PUBLIC_KEY_HEX'" \
    --session-arg=amount:"u512='900000000000'" \

Argument Explanation

Remember the deploy_hash returned in the response to query its status later.

Check that you bonding request worked

Sending a transaction to the network does not mean that the transaction processed successfully. It’s important to check to see that the contract executed properly:

casper-client get-deploy --node-address <DEPLOY_HASH> | jq .result.execution_results

Replace <DEPLOY_HASH> with the deploy hash of the transaction you want to check.

Query the auction info and look for your bid

To determine if the bid was accepted, execute the following command:

casper-client get-auction-info --node-address

The bid should appear among the returned bids. If the public key associated with a bid appears in the validator_weights structure for an era, then the account is bonded in that era.

Please note that the Casper Testnet program is implemented by providing rewards through the Casper Association (CA), a not-for-profit, Switzerland-domiciled organization responsible for overseeing the Casper network and supporting its organic evolution and continued decentralization. MAKE Technology LLC is not affiliated with the Casper Association, and has no control over the program sponsorship or the incentivized reward program, and is hosting these guides and documents as a service to the Casper community only.