Deposit BTC

The user adds more Bitcoin to their existing vault as additional collateral, keeping their borrowed UNIT amount unchanged, but improving their collateralization ratio (making liquidation less likely). This is a single transaction which updates the relevant vault record to reflect the increased Bitcoin collateral and its effect on the liquidation price.

The user initiates a transaction to add more BTC collateral to their existing vault UTXO. The MPC Network verifies the incoming BTC deposit amount and confirms the transaction. The transaction builder constructs a PSBT that combines the new BTC with the existing vault collateral. The outputs include an updated vault UTXO with the increased BTC collateral amount, while maintaining the same borrowed UNIT position. In a second transaction, the updated vault state is processed, handling the network fees for both transactions to ensure atomicity. This generates an updated vault token reflecting the new total collateral amount and improved collateralization ratio. The vault UTXO maintains both the user update path and the guardian/oracle liquidation path, with the increased collateral providing a larger safety margin. An OP_RETURN output records the new vault state with the updated collateral amount and improved collateral ratio.

Deposit BTC Transaction Diagram