Historical reference — The original USDJ/CDP system has been discontinued
This article describes the original USDJ/CDP system, which was shut down on November 17, 2025. The mechanisms and procedures described below are retained for historical reference and should not be treated as current operating instructions.
For updated fund-handling arrangements and exchange options, please refer to Updates on Handling of Funds Not Timely Returned Following USDJ System Shutdown.
Historical CDP overview
The original system allowed users to lock TRX collateral in a Collateralized Debt Position (CDP) and generate USDJ against it. This text-only reference summarizes that historical workflow. It does not provide instructions for using an active service.
The collateralization ratio was the value of TRX collateral divided by the value of outstanding USDJ debt, multiplied by 100%. The collateral value had to be at least 150% of the debt value under the historical rules. Collateral price changes could alter this ratio.
1. Create a CDP and generate USDJ
The historical interface used TronLink to connect a wallet. A holder specified the amount of TRX to lock and the amount of USDJ to generate. The “Stake to generate USDJ” flow combined three actions: opening a CDP, depositing TRX collateral and generating USDJ. The holder reviewed the details and confirmed the transaction in the wallet. Once confirmed on-chain, the CDP had a unique identifier and recorded its collateral and debt.
2. Add or withdraw collateral
The Deposit action added TRX to an existing CDP. Adding collateral without generating additional USDJ increased the collateralization ratio. The Withdraw action removed collateral; the historical interface allowed withdrawal only when the position satisfied its collateralization requirements. Withdrawing collateral without repaying debt reduced the ratio and could increase liquidation risk.
3. Generate additional USDJ
The Generate action increased the USDJ debt of an existing CDP. Generating more USDJ against the same collateral reduced the collateralization ratio. The holder specified an amount, reviewed the resulting position and confirmed the transaction. The CDP and wallet balances updated after confirmation.
4. Repay part of the debt
The Payback or Repay action returned USDJ to reduce outstanding debt. Partial repayment while keeping collateral in the CDP increased the collateralization ratio. The applicable stability fee was settled with the repayment.
The historical documentation described two payment paths. When paying the stability fee directly with JST, the wallet needed enough JST to cover the fee. The original CDP tutorial also documented a separate “Use USDJ to pay the stability fee” option, which used a smart contract to convert USDJ into JST for payment.
The USDJ option was a selected payment path in the tutorial; it should not be interpreted as an automatic fallback whenever the wallet had insufficient JST. The statement that insufficient JST would cause a payment to fail applies to direct JST payment, rather than every payment path described in the historical documentation.
5. Close a CDP
Closing a CDP required the holder to repay all outstanding USDJ debt, settle the stability fee and retrieve the locked TRX collateral. The original tutorial described selecting the USDJ fee-payment option for this flow. The closure and return of collateral completed after the transaction was confirmed.
Key terms in the historical interface
- CDP ID: The unique identifier of a collateralized debt position.
- Collateralization ratio: Collateral value divided by outstanding USDJ debt value, multiplied by 100%.
- Minimum ratio: The collateralization threshold used to determine whether a position was eligible for liquidation.
- Current price: The collateral price used to value the position.
- Liquidation penalty: A penalty applied when a position was liquidated, deducted from the collateral under the historical rules.
- Stability fee: A fee accrued on USDJ debt based on the applicable annualized borrowing rate and settled when repaying debt.
Current fund-handling arrangements
The original USDJ/CDP service is no longer available. For current arrangements and exchange options, use the official update linked at the top of this article.