# POST /api/v1/loans/accrue-interest

> Run interest accrual across all active loans

- **Tag:** loans
- **Operation ID:** `run_loan_interest_accruals_api_v1_loans_accrue_interest_post`

## Description

Accrue interest on every active loan through a date.

**Request Body:**
- `through_date`: Date to accrue through (typically a month-end).

**Effect:**
- Posts one accrual journal entry per loan with interest due
  (actual/365 simple interest on the outstanding balance).
- Loans with nothing to accrue are skipped, so this is safe to run
  as a recurring month-end batch.

**Returns:** Per-loan accrual results and the total interest posted.

## Authentication

Bearer token in `Authorization` header.
Required header: `x-business-id: <business uuid>`.

## Request body

Schema: `LoanRunAccrualsRequest`

- `through_date` (string · date · required)

## Responses

### 201 — Successful Response

Schema: `SuccessEnvelope_LoanRunAccrualsResponse_`

- `success` (boolean)
- `message` (string)
- `code` (string)
- `data` (LoanRunAccrualsResponse)

### 400 — Bad Request - Invalid input

### 401 — Unauthorized - Authentication required

### 403 — Forbidden - Insufficient permissions

### 422 — Validation Error

Schema: `HTTPValidationError`

- `detail` (array · ValidationError) → `ValidationError`
  - `loc` (array · string | integer · required)
  - `msg` (string · required)
  - `type` (string · required)
  - `input` (object)
  - `ctx` (object)

## Code samples

### cURL

```bash
curl -X POST 'https://api.ondayzero.com/api/v1/loans/accrue-interest' \
  -H 'Authorization: Bearer dz_your_token' \
  -H 'x-business-id: YOUR_BUSINESS_ID' \
  -H 'Content-Type: application/json' \
  -d '{
  "through_date": "2026-01-01"
}'
```

### JavaScript

```javascript
const response = await fetch('https://api.ondayzero.com/api/v1/loans/accrue-interest', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer dz_your_token',
    'x-business-id': 'YOUR_BUSINESS_ID',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "through_date": "2026-01-01"
}),
});
const data = await response.json();
```

### Python

```python
import httpx

headers = {
    "Authorization": "Bearer dz_your_token",
    "x-business-id": "YOUR_BUSINESS_ID",
}

payload = {
  "through_date": "2026-01-01"
}

response = httpx.post("https://api.ondayzero.com/api/v1/loans/accrue-interest", headers=headers, json=payload)
data = response.json()
```

## See also

- HTML version: https://www.ondayzero.com/docs/reference/loans/run-loan-interest-accruals
- OpenAPI slice: https://www.ondayzero.com/docs/reference/loans/run-loan-interest-accruals/openapi.json
- Other endpoints in **loans**: https://www.ondayzero.com/docs/reference/loans