👶Babylon

Testnet

Initialize the Node Directory​

First, initialize a node configuration directory under ~/.babylond. The $NODENAME variable specifies the name you aim to give your node.

babylond init $NODENAME --chain-id bbn-test-3

Then, retrieve the genesis file and place it in the node directory:

wget https://github.com/babylonchain/networks/raw/main/bbn-test-3/genesis.tar.bz2
tar -xjf genesis.tar.bz2 && rm genesis.tar.bz2
mv genesis.json ~/.babylond/config/genesis.json

Add Peers and Modify Configuration​

Edit the configuration file at ~/.babylond/config/config.toml and modify the seeds and persistent_peers attributes to contain appropriate seeds and peers of your choice. The full list of Babylon approved seeds and peers can be found under the bbn-test-3 network info page.

Edit the configuration file at ~/.babylond/config/app.toml and modify the btc-network attribute to contain the appropriate BTC network parameters as below and iavl-cache-size=0 to handle caching issues.

iavl-cache-size = 0

[btc-config]
network = "signet"

On the same file, you can also modify the minimum-gas-prices attribute and set it to a value of your choosing. For example,

minimum-gas-prices = "0.00001ubbn"

Setup Cosmovisor​

To install the latest version of Cosmovisor

go install cosmossdk.io/tools/cosmovisor/cmd/cosmovisor@latest

Create the necessary directories

mkdir -p ~/.babylond
mkdir -p ~/.babylond/cosmovisor
mkdir -p ~/.babylond/cosmovisor/genesis
mkdir -p ~/.babylond/cosmovisor/genesis/bin
mkdir -p ~/.babylond/cosmovisor/upgrades

Copy the babylond binary into the cosmovisor/genesis folder

cp $GOPATH/bin/babylond ~/.babylond/cosmovisor/genesis/bin/babylond

Setup a cosmovisor service:

sudo tee /etc/systemd/system/babylond.service > /dev/null <<EOF
[Unit]
Description=Babylon daemon
After=network-online.target

[Service]
User=$USER
ExecStart=$(which cosmovisor) run start --x-crisis-skip-assert-invariants
Restart=always
RestartSec=3
LimitNOFILE=infinity

Environment="DAEMON_NAME=babylond"
Environment="DAEMON_HOME=${HOME}/.babylond"
Environment="DAEMON_RESTART_AFTER_UPGRADE=true"
Environment="DAEMON_ALLOW_DOWNLOAD_BINARIES=false"

[Install]
WantedBy=multi-user.target
EOF

Start the Node​

sudo -S systemctl daemon-reload
sudo -S systemctl enable babylond
sudo -S systemctl start babylond

You can check the status of the node by running

systemctl status babylond

Run a Validator

Create a Keyring and Get Funds​

The Getting Testnet Tokens page contains detailed instructions on how to create a keyring and get funds for it through a faucet.

Create a BLS key​

Validators are expected to submit a BLS signature at the end of each epoch. To do that, a validator needs to have a BLS key pair to sign information with.

Using the address that you created on the previous step ($ADDR variable):

babylond create-bls-key $ADDR

This command will create a BLS key and add it to the ~/.babylond/config/priv_validator_key.json. This is the same file that stores the private key that the validator uses to sign blocks. Please ensure that this file is secured properly.

After creating a BLS key, you need to restart your node to load this key into memory. If you followed the setting up a node guide, you would have to

sudo systemctl stop babylond
sudo systemctl start babylond

Modify the Configuration​

It is strongly recommended to modify the timeout_commit value under ~/.babylond/config/config.toml. This value specifies how long a validator will wait before commiting a block before starting on a new height. More information can be found here. Given that Babylon aims to have a 30 second time between blocks, set this value to:

timeout_commit = "30s"

Create the Validator​

Contrary to a vanilla Cosmos SDK chain, a validator for Babylon is created through the babylond tx checkpointing create-validator command. This command expects that a BLS validator key exists under the ~/.babylond/config/priv_validator_key.json.

To create the validator (using sample parameters):

# Note the variables
# - $CHAIN_ID the chain ID
# - $VAL_KEY the name of the key (with a test keyring backend) used for the validator
babylond tx checkpointing create-validator /path/to/validator.json \
    --chain-id="$CHAIN_ID" \
    --gas="auto" \
    --gas-adjustment="1.5" \
    --gas-prices="0.025ubbn" \
    --from=$VAL_KEY

where /path/to/validator.json contains

# - $AMOUNT the amount to delegate in ubbn, e.g. 1000000ubbn (must be less than the delegator's balance, and unit must be included)
{
  "pubkey": {"@type":"/cosmos.crypto.ed25519.PubKey","key":"BnbwFpeONLqvWqJb3qaUbL5aoIcW3fSuAp9nT3z5f20="},
  "amount": "$AMOUNT",
  "moniker": "my-moniker",
  "website": "https://myweb.site",
  "security": "[e-mail]",
  "details": "description of your validator",
  "commission-rate": "0.10",
  "commission-max-rate": "0.20",
  "commission-max-change-rate": "0.01",
  "min-self-delegation": "1"
}

and pubkey can be obtained through the following command

babylond tendermint show-validator

In order to become an active validator, you need to have more ubbn tokens bonded than the last validator ordered by the tokens bonded (or the validator set to not be full) as well as have at least 1000000ubbn bonded.

Verify your Validator​

On the Babylon system, one can become a validator only after an epoch ends. For the testnet, an epoch lasts for around 1 hour.

To verify that you have become a validator, first find your validator address:

babylond keys show $KEYNAME -a --bech val

where $KEYNAME is the name of the key that you used for the self-delegation (e.g. my-key on our example). This will return an address which you can use as the $ADDR variable to perform the following query:

babylond query staking validator $ADDR

If all goes well, you should see a response indicating the parameters that you specified on the create-validator transaction.

After the epoch ends and if you have enough stake to be an active validator, performing this query will return you a status BOND_STATUS_BONDED. Congrats! You are now a validator on the Babylon system.