# CDPs Mento’s CDP system is a **fork of** [**Liquity v2**](https://www.liquity.org/) maintained in a **separate repository**: [**mento-protocol/bold**](https://github.com/mento-protocol/bold). Same contract architecture and mechanics as Liquity v2, with **USDm as collateral** and **FX-pegged Mento stables** as the debt token; Mento deploys **one independent instance per FX currency**, each with its own TroveManager, StabilityPool, and FX price feed. In practice, **all Mento CDP deployments are FX CDPs**: borrow `XXXm`, post `USDm`, and price the branch from an FX feed via `FXPriceFeed -> OracleAdapter`. For a protocol-level overview (what you can do, collateral vs debt, Stability Pool, app/SDK usage), see [**CDPs**](/mento-v3/dive-deeper/cdp.md) in Dive Deeper. *** ## Contract overview The CDP system is implemented by the Liquity v2 contract suite. Mento’s fork lives in [mento-protocol/bold](https://github.com/mento-protocol/bold) (not in mento-core): | Role | Purpose | | ---------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | **BorrowerOperations** | Open, adjust, and close troves; add/withdraw collateral, borrow, repay. | | **TroveManager** | Trove state, collateralization checks, liquidations, redemption order. | | **Stability Pool** | Holds debt-token deposits; absorbs debt from liquidated troves in exchange for collateral; used by CDPLiquidityStrategy for expansion rebalancing. | | **Collateral / Debt** | In Mento’s fork: collateral is **USDm**; debt is the FX-pegged stable (e.g. GBPm) for that instance. | | **FXPriceFeed** | Mento-specific: fetches FX rates (e.g. GBP/USD) from Mento’s OracleAdapter; supports watchdog-triggered shutdown. | | **SystemParams** | Minimum debt, liquidation penalties, CCR/MCR/BCR, redemption fee floor, gas compensation, etc. | Liquidations, redemptions, gas compensation, and fee flows follow Liquity v2; Mento’s fork differs in **collateral (USDm)**, **debt (FX-pegged tokens)**, **oracles (FXPriceFeed)**, and **multi-instance deployment**. ## FX Market Hours Because Mento CDPs use `FXPriceFeed`, and `FXPriceFeed.fetchPrice()` calls `OracleAdapter.getFXRateIfValid(rateFeedID)`, **all Mento CDP branches inherit FX market-hours gating**. When the FX market is closed, price-dependent CDP operations revert instead of using a stale weekend price. Under the current `MarketHoursBreaker`, FX is treated as closed: * from **Friday 21:00 UTC** until **Sunday 23:00 UTC** * on **Dec 25** and **Jan 1** * after **22:00 UTC** on **Dec 24** and **Dec 31** ### Blocked While FX Markets Are Closed These operations depend on `priceFeed.fetchPrice()` and therefore are **not available** during weekend / holiday FX closures: * **Open trove** * **Adjust trove**: add collateral, withdraw collateral, borrow more, repay, combined adjustments * **Close trove** * **Zombie trove adjustment / reactivation** * **Standard liquidations** * **Standard redemptions** * **Some interest-rate / batch-manager operations** when they require a price-dependent upfront-fee or TCR check ### Still Available These user-facing Stability Pool operations do **not** call `fetchPrice()` and therefore are **still available** during FX closures: * **Deposit to Stability Pool** * **Withdraw from Stability Pool** * **Claim accumulated Stability Pool collateral gains** The indirect effect is that the Stability Pool usually will **not** receive new liquidation-driven offsets while the FX market is closed, because standard liquidations are themselves blocked. ### Shutdown Exception If a CDP branch has already entered **shutdown**, `FXPriceFeed` returns `lastValidPrice` instead of calling the live oracle path. In that emergency mode, the branch follows shutdown-specific logic such as **urgent redemption**, rather than the normal market-hours-gated flow. **Critical risk considerations** (USDm depeg risk, FX exposure for borrowers and SP depositors, Stability Pool FX loss on liquidations, and double liquidation risk from both FX moves and USDm depeg) are summarized in [**CDPs (Dive Deeper)**](/mento-v3/dive-deeper/cdp.md#critical-risk-considerations) and discussed in depth in the [mento-protocol/bold README](https://github.com/mento-protocol/bold). *** ## Where to find full contract documentation Contract-level behavior, state variables, and all protocol rules are not re-documented here. * [**Liquity v2 documentation**](https://docs.liquity.org/) — technical resources and contract behavior. * [**Liquity v2 whitepaper**](https://www.liquity.org/blog/liquity-v2-whitepaper) — design and economics. **Mento fork:** The [**mento-protocol/bold** README](https://github.com/mento-protocol/bold) describes key differences (USDm collateral, FX-pegged stables, FXPriceFeed, multi-instance architecture) and Mento-specific risks and economics. For deployment addresses, parameter choices, and integration with [CDPLiquidityStrategy](/mento-v3/build/smart-contracts/liquidity-strategies.md), see [mento-core](https://github.com/mento-protocol/mento-core) and the [Deployments](/mento-v3/build/deployments.md) section. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.mento.org/mento-v3/build/smart-contracts/cdps.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. 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