Trust lines
On the XRPL, an account can only hold an issued token after opening a trust line to its issuer. XRP requires no trust line; USDC.axl and the XRP/USDC LP token do. The app checks the relevant trust line before every action that sends or delivers an issued token, and offers to open or raise it in one transaction.
Opening a trust line
When you supply or repay a token your wallet cannot hold, the modal displays a Trustline required panel in place of the amount form:
Your wallet has no trustline to USDC.axl (issuer rfmS…Yhw). You cannot hold or send this token without it. Opening it locks 0.2 XRP of your balance as XRPL reserve.
Click Open ‹asset› trustline and approve the TrustSet transaction in your wallet. The trust line is opened with a limit of 1,000,000 units. The amount form is then displayed.
When you borrow or withdraw a token your wallet cannot receive, the same panel is displayed with the message Borrowed or withdrawn tokens cannot be delivered to your wallet without it.
XRPL reserve
Each trust line locks an additional 0.2 XRP of owner reserve for as long as it exists. The button is disabled with Not enough spendable XRP for the 0.2 XRP reserve when your balance cannot cover it.
Raising a trust line limit
A trust line has a limit: the maximum balance the account accepts. The XRPL rejects a delivery that would bring the balance above the limit. For a borrow or a withdrawal, the rejection would happen after the action has executed on XRPL EVM: the tokens would already have left your position, and the delivery would need a manual recovery by the bridge operators. The app therefore checks the trust line before signing. Two cases apply in Securd:
- an LP trust line created by an AMM deposit has a limit of 0;
- a trust line whose limit is lower than the amount being borrowed or withdrawn.
Before a borrow or a withdrawal, the modal displays:
Trust line limit too low Your XRP/USDC LP trust line cannot receive this amount — its limit is too low (an AMM deposit opens it with a limit of 0). Raise the limit to 1000000 XRP/USDC LP before withdrawing or borrowing.
Click Raise ‹asset› trust line limit and approve the transaction in your wallet. The new limit is 1,000,000 units, or twice the balance after the delivery, whichever is higher.
If the trust line can receive part of the amount but not all of it, the amount form remains displayed with the button disabled: Your ‹asset› trust line limit is too low to receive this amount — raise it first.
USDC.axl and Circle USDC
Two tokens named USDC exist on the XRPL.
| Token | Issuer | Accepted by Securd |
|---|---|---|
| USDC.axl (bridged by Axelar) | rfmS3zqrQrka8wVyhXifEeyTwe8AMz2Yhw (Axelar gateway) | Yes. The only USDC accepted by the USDC market |
| Circle USDC | rGm7WCVp9gb4jZHWTEtGUr4dd74z2XuWhE | No |
Circle USDC sent to the Axelar gateway cannot be recovered
The app only builds payments in USDC.axl. However, a manual payment of Circle USDC to the Axelar gateway bridges to a different token on XRPL EVM and cannot be returned. Acquire USDC.axl for use with Securd, and verify the issuer before any manual payment.
The XRP/USDC AMM pool holds Circle USDC as its own asset. This does not affect Securd: the asset you supply is the LP token, not the USDC in the pool.
Wallet column
In Supply Markets, the Wallet column displays — for a token without a trust line. Once the trust line exists, the balance is displayed and refreshed every 15 seconds.