# Add item(s)

`POST` `/lists/{list_id}/items`

Adds or updates an item in an existing list.

## Parameters

- **list_id** (`string`, required) — List ID without the "@" prefix.

## Request body

- **item** (`object`, required)
  - **values** (`object`, required) — Item content. Validated according to the list type.
  - **description** (`string`) — Optional item description for display in the admin panel.
  - **expiration_in_hours** (`integer`) — Number of hours for automatic expiration. Leave blank to register the item permanently.

```json
{
  "item": {
    "values": null,
    "description": "string",
    "expiration_in_hours": 6
  }
}
```

## Responses

### 201 — Item(s) created successfully.

- **items** (`array`) — List of created items
  - **id** (`string`) — Item ID.
  - **value** (`string`) — Item content.
  - **description** (`string`) — Optional item description.
  - **expires_at** (`date-time`) — Item expiration date and time. If the item is permanent, this field will be null.

```json
{
  "items": [
    {
      "id": "string",
      "value": "string",
      "description": "string",
      "expires_at": "2024-01-01T00:00:00Z"
    }
  ]
}
```

### 401 — Invalid access credentials

- **errors** (`array`)
  - **field** (`string`) — Request field where the error occurred
  - **type** (`string`) — Error type code
  - **message** (`string`) — Error message

```json
{
  "errors": [
    {
      "field": "string",
      "type": "string",
      "message": "string"
    }
  ]
}
```

### 422 — Invalid parameters

- **errors** (`array`)
  - **field** (`string`) — Request field where the error occurred
  - **type** (`string`) — Error type code
  - **message** (`string`) — Error message

```json
{
  "errors": [
    {
      "field": "string",
      "type": "string",
      "message": "string"
    }
  ]
}
```

### 404 — Object not found

- **errors** (`array`)
  - **field** (`string`) — Request field where the error occurred
  - **type** (`string`) — Error type code
  - **message** (`string`) — Error message

```json
{
  "errors": [
    {
      "field": "string",
      "type": "string",
      "message": "string"
    }
  ]
}
```