> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trusset.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Repay Loan

> Repay loan debt, interest first then principal

Repays part or all of a loan's outstanding debt. Accrued interest is settled before principal. Anyone can repay any loan, so a third party can rescue a position approaching liquidation.

Two transactions are required: an approval on the borrow asset, then the repayment. Both come back as ordered steps.

## Path Parameters

<ParamField path="marketId" type="string" required>Market ID.</ParamField>

## Body Parameters

<ParamField body="loanId" type="integer" required>
  On-chain loan ID. Must be a positive integer sent as a JSON number.
</ParamField>

<ParamField body="amount" type="string" required>
  Amount to repay as a decimal string in borrow asset units. The contract caps repayment at the total debt, so overpaying does not transfer more than owed.
</ParamField>

<ParamField body="txHash" type="string">
  Hash of the transaction you broadcast for this operation. Send it to confirm the transaction and record the result. Omit it to receive the calldata.
</ParamField>

## Response Fields

<ResponseField name="data" type="object">
  <Expandable>
    <ResponseField name="txHash" type="string">Transaction hash. Returned when confirming with `txHash`.</ResponseField>
    <ResponseField name="loanId" type="integer">Loan ID, echoed back. Returned when confirming with `txHash`.</ResponseField>
    <ResponseField name="repaidAmount" type="string">Amount submitted, echoed back. Returned when confirming with `txHash`.</ResponseField>
    <ResponseField name="action" type="string">`SIGN_TRANSACTIONS` when `txHash` is omitted.</ResponseField>
    <ResponseField name="steps" type="array">Ordered `approve` then `repay` transactions. Returned when `txHash` is omitted.</ResponseField>
  </Expandable>
</ResponseField>

<Note>
  Repaying the full debt does not release collateral on its own. Follow with [Close Loan](/endpoints/external-securities-lending/close-loan) to unlock the pledged tokens and mark the position repaid.
</Note>

<Tip>
  Read `principal` and `accruedInterest` from [Get Loan](/endpoints/external-securities-lending/get-loan) immediately before repaying. Interest accrues per block, so a payoff quote computed even a minute earlier will leave dust behind and block the subsequent close.
</Tip>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST "https://api.trusset.org/lending-external-securities/api/positions/{marketId}/repay" \
    -H "X-API-Key: trusset_your_key_here" \
    -H "Content-Type: application/json" \
    -d '{"loanId": 5, "amount": "10000"}'
  ```

  ```typescript TypeScript theme={null}
  const loanRes = await fetch(
    `https://api.trusset.org/lending-external-securities/api/positions/${marketId}/loan/5`,
    { headers: { 'X-API-Key': 'trusset_your_key_here' } }
  );
  const { data: loan } = await loanRes.json();
  const payoff = (Number(loan.principal) + Number(loan.accruedInterest)) * 1.0001;

  await fetch(
    `https://api.trusset.org/lending-external-securities/api/positions/${marketId}/repay`,
    {
      method: 'POST',
      headers: {
        'X-API-Key': 'trusset_your_key_here',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({ loanId: 5, amount: payoff.toFixed(6) })
    }
  );
  ```
</RequestExample>

<ResponseExample>
  ```json Calldata Response theme={null}
  {
    "success": true,
    "data": {
      "action": "SIGN_TRANSACTIONS",
      "steps": [
        {
          "action": "SIGN_TRANSACTION",
          "transaction": { "to": "0x98aD0ca091552e23C564B41C74282e5343D03E8a", "data": "0x..." },
          "functionName": "approve",
          "description": "Approve the market to pull USDC"
        },
        {
          "action": "SIGN_TRANSACTION",
          "transaction": { "to": "0x70A0...", "data": "0x..." },
          "functionName": "repay"
        }
      ]
    }
  }
  ```

  ```json Confirmed Response theme={null}
  {
    "success": true,
    "data": {
      "txHash": "0xabc...def",
      "loanId": 5,
      "repaidAmount": "10000"
    }
  }
  ```

  ```json Error - Preflight Failed theme={null}
  {
    "success": false,
    "error": {
      "code": "PREFLIGHT_FAILED",
      "message": "execution reverted: LoanNotActive"
    }
  }
  ```
</ResponseExample>

## Errors

| Code                | HTTP  | Cause                                                                  |
| ------------------- | ----- | ---------------------------------------------------------------------- |
| `NO_MARKET_ADDRESS` | `400` | The market has no on-chain address recorded                            |
| `PREFLIGHT_FAILED`  | `400` | The repayment reverted during simulation. `message` carries the reason |
| `REPAY_FAILED`      | `400` | The transaction failed on-chain                                        |
| `VALIDATION_ERROR`  | `400` | `amount` carries more decimal places than the borrow asset supports    |