# contractorOps.history.rateBackfill.apply

Save agreement-derived hourly rate snapshots for explicitly selected imported timesheets after reviewing the preview. Supply each history row id and expectedRevision plus idempotencyKey. Rechecks the agreement and source row atomically; a changed, split-rate or ambiguous week fails without saving any row. Does not mark paid, prepare, approve or send a payout.

`POST /api/v1/accounting/contractorOps.history.rateBackfill.apply`

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

MCP tool: `accounting_contractor_ops_history_rate_backfill_apply`

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `rows` | array of objects | Yes | 1–500 items. |
| `rows[].id` | string (ID) | Yes | The record's ID. |
| `rows[].expectedRevision` | integer | Yes | The record's current revision, from the last time you read it. If someone changed the record since, the request is refused with a conflict so you can reload and check before trying again. at most 9007199254740991; greater than 0. |
| `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/contractorOps.history.rateBackfill.apply \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "rows": [
    {
      "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
      "expectedRevision": 3
    }
  ]
}'
```

Reference page: https://app.getoatmilk.com/docs/api/contractorOps.history.rateBackfill.apply