# Add Auto-Assign Rule

Add an automatic book assignment rule to a collection.

**Endpoint**: `POST /api/collections/{id}/rules`
**Auth**: Required
**Content-Type**: `application/json`

## Path Parameters

| Parameter | Type | Required | Description |
|-----------|------|-----------|-------------|
| id | string (UUID) | Yes | Collection UUID |

## Request Body

| Field | Type | Required | Description |
|--------|------|-----------|-------------|
| field | string | Yes | Field to match on (genre, author, series, language, publisher, copyright_year, tags) |
| operator | string | Yes | Comparison operator (equals, not_equals, contains, not_contains, starts_with, ends_with, greater_than, less_than) |
| value | string/number | Yes | Value to compare against |
| priority | integer | No | Rule priority (1 = highest, default: 1) |
| enabled | boolean | No | Whether rule is active (default: true) |

### Supported Fields

| Field | Type | Description |
|-------|------|-------------|
| genre | string | Book genre |
| author | string | Book author |
| series | string | Book series name |
| language | string | Book language |
| publisher | string | Publisher name |
| copyright_year | number | Publication year (numeric comparison) |
| tags | string | Book tags |

### Supported Operators

| Operator | Type | Description |
|----------|------|-------------|
| equals | all | Exact match |
| not_equals | all | Not equal |
| contains | string | Contains substring (case-insensitive) |
| not_contains | string | Does not contain |
| starts_with | string | Starts with (case-insensitive) |
| ends_with | string | Ends with (case-insensitive) |
| greater_than | number | Greater than |
| less_than | number | Less than |

### Example Request

```json
{
  "field": "genre",
  "operator": "equals",
  "value": "Science Fiction",
  "priority": 1,
  "enabled": true
}
```

## Response (201 Created)

```json
{
  "id": "rule-uuid-here",
  "field": "genre",
  "operator": "equals",
  "value": "Science Fiction",
  "priority": 1,
  "enabled": true,
  "created_at": "2026-02-01T10:00:00Z"
}
```

## Error Responses

| Code | Description |
|------|-------------|
| 400 | Invalid request (validation failed) |
| 401 | Authentication required |
| 404 | Collection not found |
| 500 | Internal server error |

## Try It Out
