Join the Testnet

::: warning You need to install spend before you go further :::

Setting Up a New Node

These instructions are for setting up a brand new full node from scratch.

First, initialize the node and create the necessary config files:

spend init <your_custom_moniker>

::: warning Note Monikers can contain only ASCII characters. Using Unicode characters will render your node unreachable. :::

You can edit this moniker later, in the ~/.spend/config/config.toml file:

# A custom human readable name for this node
moniker = "<your_custom_moniker>"

You can edit the ~/.spend/config/spend.toml file in order to enable the anti spam mechanism and reject incoming transactions with less than the minimum gas prices:

# This is a TOML config file.
# For more information, see https://github.com/toml-lang/toml

##### main base config options #####

# The minimum gas prices a validator is willing to accept for processing a
# transaction. A transaction's fees must meet the minimum of any denomination
# specified in this config (e.g. 10ustaking).

minimum-gas-prices = ""

Your full node has been initialized!

Genesis & Seeds

Copy the Genesis File

Fetch the testnet's genesis.json file into spend's config directory.

mkdir -p $HOME/.spend/config
curl https://raw.githubusercontent.com/Spend/Spendchain/master/genesis/genesis.json > $HOME/.spend/config/genesis.json

To verify the correctness of the configuration run:

spend start

Add Seed Nodes

Your node needs to know how to find peers. You'll need to add healthy seed nodes to $HOME/.spend/config/config.toml

For more information on seeds and peers, you can read this.

A Note on Gas and Fees

::: warning On Spend Hub testnet, the accepted denom is ustaking, where 1staking = 1.000.000ustaking :::

Transactions on the Spend Hub network need to include a transaction fee in order to be processed. This fee pays for the gas required to run the transaction. The formula is the following:

fees = ceil(gas * gasPrices)

The gas is dependent on the transaction. Different transaction require different amount of gas. The gas amount for a transaction is calculated as it is being processed, but there is a way to estimate it beforehand by using the auto value for the gas flag. Of course, this only gives an estimate. You can adjust this estimate with the flag --gas-adjustment (default 1.0) if you want to be sure you provide enough gas for the transaction.

The gasPrice is the price of each unit of gas. Each validator sets a min-gas-price value, and will only include transactions that have a gasPrice greater than their min-gas-price.

The transaction fees are the product of gas and gasPrice. As a user, you have to input 2 out of 3. The higher the gasPrice/fees, the higher the chance that your transaction will get included in a block.

::: tip For testnet, the recommended gas-prices is 0.025ustaking. :::

Set minimum-gas-prices

Your full-node keeps unconfirmed transactions in its mempool. In order to protect it from spam, it is better to set a minimum-gas-prices that the transaction must meet in order to be accepted in your node's mempool. This parameter can be set in the following file ~/.spend/config/spend.toml.

The initial recommended min-gas-prices is 0.025ustaking, but you might want to change it later.

Run a Full Node

Start the full node with this command:

spend start

Check that everything is running smoothly:

spendcli status

View the status of the network with the Spend Explorer.

Export State

Spend can dump the entire application state to a JSON file, which could be useful for manual analysis and can also be used as the genesis file of a new network.

Export state with:

spend export > [filename].json

You can also export state from a particular height (at the end of processing the block of that height):

spend export --height [height] > [filename].json

If you plan to start a new network from the exported state, export with the --for-zero-height flag:

spend export --height [height] --for-zero-height > [filename].json

Verify testnet

Help to prevent a catastrophe by running invariants on each block on your full node. In essence, by running invariants you ensure that the state of testnet is the correct expected state. One vital invariant check is that no stakings are being created or destroyed outside of expected protocol, however there are many other invariant checks each unique to their respective module. Because invariant checks are computationally expensive, they are not enabled by default. To run a node with these checks start your node with the assert-invariants-blockly flag:

spend start --assert-invariants-blockly

If an invariant is broken on your node, your node will panic and prompt you to send a transaction which will halt testnet. For example the provided message may look like:

invariant broken:
    loose token invariance:
        pool.NotBondedTokens: 100
        sum of account tokens: 101
    CRITICAL please submit the following transaction:
        spendcli tx crisis invariant-broken staking supply

When submitting a invariant-broken transaction, transaction fee tokens are not deducted as the blockchain will halt (aka. this is a free transaction).

Upgrade to Validator Node

You now have an active full node. What's the next step? You can upgrade your full node to become a Spend Validator. The top 100 validators have the ability to propose new blocks to the Spend Hub. Continue onto the Validator Setup.