# reconciliation.refund.apply

Save the exact reviewed mixed transfer/fee refund from reconciliation.refund.preview. Requires the same selected entries, amounts, reviewed revisions, sourceFingerprint, evidence-supported reason, confirmed:true and a stable idempotencyKey. Atomically reuses the existing bank-only credit record when selected, allocates cash once, links both original reversals, preserves source documents and returns before/after postings. No money moves or notifications are sent.

`POST /api/v1/accounting/reconciliation.refund.apply`

Permissions: `accounting:read`, `accounting:write` · Roles: admin, finance · Idempotency key required

MCP tool: `accounting_reconciliation_refund_apply`

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `transactionId` | string (ID) | Yes | The ID of a bank or card transaction, from transactions.list. |
| `expectedTransactionRevision` | integer | Yes | The bank transaction's current revision, from the last time you read it. at most 9007199254740991; greater than 0. |
| `transferEntryId` | string (ID) | Yes | The ID of the related record. |
| `expectedTransferRevision` | integer | Yes | The related record's current revision, from the last time you read it. at most 9007199254740991; greater than 0. |
| `feeEntryId` | string (ID) | Yes | The ID of the related record. |
| `expectedFeeRevision` | integer | Yes | The related record's current revision, from the last time you read it. at most 9007199254740991; greater than 0. |
| `transferAmountMinor` | string | Yes | An amount in cents (the currency's smallest unit), written as a whole-number string such as "1250" for $12.50. Matches ^[1-9]\d{0,18}$. |
| `feeAmountMinor` | string | Yes | An amount in cents (the currency's smallest unit), written as a whole-number string such as "1250" for $12.50. Matches ^[1-9]\d{0,18}$. |
| `creditEntryId` | string (ID) |  | The ID of the related record. |
| `expectedCreditRevision` | integer |  | The related record's current revision, from the last time you read it. at most 9007199254740991; greater than 0. |
| `sourceFingerprint` | string | Yes | SHA-256 hash as 64 lowercase hex characters. |
| `reason` | string | Yes | A short note saying why, kept in the record's history. 10–1000 characters. |
| `confirmed` | true | Yes |  |
| `idempotencyKey` | string | Yes | Any unique text you generate once per intended change, so a retried request only happens once. Send it as the Idempotency-Key header instead if you prefer; if you send both they must match. 8–200 characters. |

## Example request

```bash
curl https://app.getoatmilk.com/api/v1/accounting/reconciliation.refund.apply \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "transactionId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
  "expectedTransactionRevision": 3,
  "transferEntryId": "1a2b3c4d-5e6f-4a7b-8c9d-0e1f2a3b4c5d",
  "expectedTransferRevision": 3,
  "feeEntryId": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
  "expectedFeeRevision": 3,
  "transferAmountMinor": "1",
  "feeAmountMinor": "1",
  "sourceFingerprint": "9f2b5c1d7e3a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2b4c",
  "reason": "Synthetic example from the docs",
  "confirmed": true
}'
```

Reference page: https://app.getoatmilk.com/docs/api/reconciliation.refund.apply