Starter is the simplest possible hook: it just accepts all transactions and logs that it is running.
to test:
Carbon hook sends a percentage of outgoing payments to a dedicated account.
The beneficiary account is hard-coded, so while the default version of carbon.c works, it works with an account that cannot be imported into Hooks Builder (unless you know its secret key). See later examples for how to parametrize a hook.
to test:
Peggy hook provides an automated way to issue and redeem an over-collateralised XRP-backed stablecoin.
Sending XRP to it creates a vault and sends back stablecoin, which can be redeemed against the vault to get back the original XRP.
The exchange rate between XRP and stablecoin is the limit set on a trustline established between two special oracle accounts.
If the value of XRP falls too far, the vault gets under a minimum collateralization threshold. This means anyone who wants to top up the vault above the threshold can come along and take it over.
Notary hook collects signatures for multi-sign transactions. It has two modes of operation:
It relies on the signer list on the account the hook is running on. Only accounts on this list can propose and endorse multisign transactions through this hook.
to test:
Firewall is an example of cooperating hooks: firewall hook instances filter incoming payments, based on shared state maintained by blacklist hook.
To cooperate, the hooks need information about each other, which must be obtained before deploying them, because it's passed to them as install-time parameters.
to test:
