Acala Stablecoin
Last updated
Last updated
To interact with Acala or Karura from Javascript you can use @polkadot/api
along with @acala-network/api
. You can learn more about @polkadot/api
[here]. (https://polkadot.js.org/docs/api).
We do also provide a Stablecoin SDK which provides more some automation around stablecoins.
https://github.com/AcalaNetwork/Acala/tree/master/modules/honzon
These functions only read information from the chain, and thus don't require signing transactions with a private key. Read more about state queries here: State queries docs
Returns amount of collateral
and amount of minted stablecoin as debit
for specific collateral type and account.
Note
debit
reflects the only amount of minted kUSD. The amount of debt is higher as it includes accumulated interest. To calculate the total amount to payback you need to usedebitExchangeRate
parameter (the example for fetchingdebitExchangeRate
is shown below).
Arguments
currencyId
CurrencyId
collateral currency Id
accountId
AccountId
account to fetch vaults for, can be passed as string
Example:
loan-examples/get-positions.js
Returns total amount of collateral
and amount of borrowed stablecoin as debit
for specific collateral type.
Arguments
currencyId
CurrencyId
identificator for currency used as collateral
Example:
loan-examples/total-positions.ts
Each accepted by Karura Collateral Type can have different risk parameters. These values are controlled by Karura Governance.
Arguments
currencyId
CurrencyId
identificator for currency used as collateral
Return values
maximumTotalDebitValue
Number
maximum amount of KUSD that can be borrowed for one vault
interestRatePerSec
Percent
the percentage of borrowed kUSD to be paid each next block. This amount should be added to globalInterestRatePerSec
to calculate the debt
liquidationRatio
Percent
collateral ratio (collateral value / debt value) reaching which the vault gets liquidated
liquidationPenalty
Percent
penalty that is charged from the vault if the vault gets liquidated
requiredCollateralRatio
Percent
Minimum collateral ratio till which user can borrow kUSD
Example:
loan-examples/collateral-params.ts
This parameter is used to calculate the debt. The amount of minted kUSD should be multiplied by this parameter. As the Interest rate is accumulated depends on block number, it makes sense to fetch this parameter for a certain block.
Arguments
currencyId
CurrencyId
identificator for currency used as collateral
Example:
loan-examples/debit-exchange-rate.ts
These transactions write data on-chain and require a private key to sign the transaction. To perform run test code snippets ensure that you have SEED_PHRASE
environment variable defined in your .env
file.
All operations: creating a vault, adding/removing collateral, borrowing, paying back kUSD can be done using a single method: honzon.adjustLoan
Arguments
currencyId
CurrencyId
collateral CurrencyId
collateral_adjustment
Signed Amount
positive means to deposit collateral currency into Vault, negative means withdraw collateral currency from the Vault
debit_adjustment
Signed Amount
positive means to mint some amount of stablecoin to the caller; negative means that caller will pay back stablecoin to the Vault
Example
Sets permission to transfer caller's loan to another Account (to
).
Returns Extrinsic
type that should be signed with a private key.
Arguments
currencyId
CurrencyId
collateral CurrencyId
to
AccountId
sets permission to transfer loan for this accountId
Example:
Removes permission to transfer caller's loan to another Account (to
). This method can be used to decline previously given permission.
Returns Extrinsic
type that should be signed with a private key.
Arguments
currencyId
CurrencyId
collateral CurrencyId
to
AccountId
removes permission to transfer loan for this accountId
Example:
Removes permission to transfer caller's vault to ALL accounts for all Collateral types. This method can be used to decline previously given permission.
Returns Extrinsic
type that should be signed with a private key.
Example:
Transfers Vault to the caller's account if it has permissions (if authorize
was called previously by from
account).
Returns Extrinsic
type that should be signed with a private key.
Arguments
currencyId
CurrencyId
collateral CurrencyId
from
AccountId
transfers collateral from this account to the caller
Example:
This action can be done with adjustLoan
, but there is a shortcut created for this purpose which is applied only to safe vaults (where the collateral ratio is above liquidation level) and where the debt amount is positive.
This method closes the caller's Vault by selling a sufficient amount of collateral on Karura Dex.
Returns Extrinsic
type that should be signed with a private key.
Arguments
currencyId
CurrencyId
collateral CurrencyId
max_collateral_amount
number
the maximum collateral that's allowed to be swapped in DeX to pay back the Vault
maybe_path
CurrencyId[]
swap path that can be used for swapping collateral for kUSD in DeX
Example:
Note the supply amount should be denormalised with KAR decimals for this example