# Partial Liquidation

> Markdown export of the Gearbox Protocol documentation page for agents and retrieval systems.

Canonical page: https://docs.gearbox.finance/developers/partial-liquidation
Source file: content/developers/partial-liquidation.mdx
Section router: https://docs.gearbox.finance/developers/llms.txt
Section full export: https://docs.gearbox.finance/developers/llms-full.txt

A partial liquidation repays part of a Credit Account's debt and transfers one
selected collateral asset to the liquidator at the liquidation discount. The
account remains open and must finish with a health factor of at least `1.0`.

This flow is only for immediately receivable collateral. It does not transfer
redeemers or liquidate delayed-redemption positions. Use
[Full Liquidation](https://docs.gearbox.finance/developers/full-liquidation) when an account has delayed
withdrawals.

Before continuing, [install and attach the Gearbox SDK](https://docs.gearbox.finance/developers/sdk-setup).
The caller supplies these inputs:

| Variable | Type | Meaning |
|---|---|---|
| `sdk` | `OnchainSDK` | Attached Gearbox SDK instance |
| `liquidator` | `Address` | Wallet supplying repayment and receiving collateral |
| `supportedCollateral` | `Address[]` | Collateral assets the liquidator is willing to receive |
| `supportedRepaymentTokens` | `Address[]` | Market underlyings the liquidator is willing to repay |

## 1. Find liquidatable accounts

Use the same discovery service as full liquidation, but exclude every account
that holds a delayed-withdrawal position:

```typescript
const candidates = await sdk.liquidations.getLiquidatableAccounts({
  assets: supportedCollateral,
  delayed: false,
});
```

`delayed: false` is the boundary between the two liquidation processes. Partial
liquidation does not assign redeemers to the liquidator.

The `assets` filter matches each account's main collateral. The selected output
is checked again during preview.

## 2. Inspect one candidate

Load a fresh account snapshot, confirm that no delayed withdrawal has appeared,
and calculate the default partial-liquidation parameters:

```typescript
import { isAddressEqual } from "viem";

const candidate = candidates[0];
if (!candidate) throw new Error("No supported liquidation candidates");
if (candidate.paused) throw new Error("Credit Facade is paused");

const account = await sdk.accounts.getCreditAccountData(
  candidate.creditAccount,
);
if (!account) throw new Error("Credit Account not found");
if (!account.success) throw new Error("Collateral computation failed");

const compressor = sdk.withdrawalCompressor;
if (!compressor) throw new Error("Delayed-withdrawal state unavailable");

const currentWithdrawals = await compressor.getCurrentWithdrawals(
  account.creditAccount,
);
if (
  currentWithdrawals.pending.length > 0 ||
  currentWithdrawals.claimable.length > 0
) {
  throw new Error("Use full liquidation for delayed withdrawals");
}

const creditManager = sdk.marketRegister.findCreditManager(
  account.creditManager,
);
const repaymentToken = creditManager.underlying;

if (
  !supportedRepaymentTokens.some(token =>
    isAddressEqual(token, repaymentToken),
  )
) {
  throw new Error("Unsupported repayment token");
}

const preview = sdk.accounts.defaultPartialLiquidationParams(account);

if (
  !supportedCollateral.some(token =>
    isAddressEqual(token, preview.tokenOut),
  )
) {
  throw new Error("Unsupported collateral token");
}
```

| Value | Type | Meaning |
|---|---|---|
| `account` | `CreditAccountData` | Fresh state of the account being liquidated |
| `compressor` | `IWithdrawalCompressorContract` | SDK reader used to confirm that the account has no delayed withdrawals |
| `currentWithdrawals` | `CurrentWithdrawals` | Current delayed withdrawals; partial liquidation requires both lists to be empty |
| `creditManager` | `CreditSuite` | Credit Manager suite for the account |
| `repaymentToken` | `Address` | Market underlying supplied by the liquidator |
| `preview.tokenOut` | `Address` | Collateral selected for the liquidator to receive |
| `preview.repaidAmount` | `bigint` | Amount of market underlying supplied by the liquidator |
| `preview.minSeizedAmount` | `bigint` | Minimum acceptable amount of `tokenOut` |
| `preview.optimalHF` | `bigint` | Target post-liquidation health factor, where `10000` is `100%` |

The SDK selects the most valuable enabled non-underlying collateral and
calculates a repayment intended to restore the account to its optimal health
factor. Pass the preview values explicitly when building so the transaction
matches the inspected parameters.

## 3. Obtain the execution payload

Build immediately before execution:

```typescript
const transaction = await sdk.accounts.partiallyLiquidate({
  account,
  to: liquidator,
  ...preview,
});
```

Approve `repaymentToken` for `account.creditManager` with an allowance of at
least `preview.repaidAmount`. The Credit Manager is the spender.

`transaction` contains the unsigned `partiallyLiquidateCreditAccount()` call
with current on-demand price updates. Pass the approval requirement and
transaction to the operator's existing transaction pipeline.

Execution reverts if the account is no longer liquidatable, the seized amount
is below `preview.minSeizedAmount`, or the account would remain below a health
factor of `1.0`.

## Integration boundary

This page provides Gearbox discovery, delayed-position exclusion, parameter
calculation, approval requirements, and unsigned liquidation calldata. The
operator's existing infrastructure owns execution and service operation.

## Sources

- [Gearbox SDK partial-liquidation builder](https://github.com/Gearbox-protocol/sdk/blob/next/src/sdk/accounts/CreditAccountsServiceV310.ts#L679-L724)
- [Credit Facade partial-liquidation implementation](https://github.com/Gearbox-protocol/core-v3/blob/next/contracts/credit/CreditFacadeV3.sol#L372-L438)