> ## Documentation Index
> Fetch the complete documentation index at: https://developers.criteo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Line Item Diagnostics

> Check whether line items can serve and identify the configuration issues that prevent delivery.

## Overview

Use the Line Item Diagnostics endpoint to check whether a line item is configured correctly. The response reports a status for each evaluated line item and, when requested, the configuration context, evaluated parameters, and issues that require attention.

> [!NOTE]
>
> **Availability: Coming soon**
>
> This endpoint is documented ahead of availability in the Experimental Retail Media API.

You can check one line item or a page of line items in one campaign. Your access token must be authorized to view the selected resource. See [Authentication](/retail-media/experimental/docs/authentication).

## Endpoint

| Method | Endpoint | Description | Availability |
| - | - | - | - |
| `GET` | `/diagnostics/line-item-checks` | Get diagnostics for one line item or a page of a campaign's line items. | Coming soon |

## Get Line Item Diagnostics

GET

```http theme={null}
https://api.criteo.com/experimental/retail-media/diagnostics/line-item-checks
```

Send exactly one resource selector: `line-item-id` or `campaign-id`. A line-item request returns one result. A campaign request returns a paginated result set.

### Query Parameters

| Parameter | Type | Required | Description |
| - | - | - | - |
| `line-item-id` | string | One selector is required | ID of the line item to evaluate. Do not send it with `campaign-id`. |
| `campaign-id` | string | One selector is required | ID of the campaign whose line items to evaluate. Do not send it with `line-item-id`. |
| `as-approved` | boolean | No | When `true` (default), evaluates the approved Onsite Display line item when one exists. Set to `false` to evaluate the current proposal. |
| `fields` | string | No | Comma-separated optional attributes to include: `context`, `issues`, and `parameters`. All three are included when omitted. |
| `cursor` | string | No | The cursor from the previous campaign response. Only valid with `campaign-id`; it must be a positive integer. |
| `limit` | integer | No | Maximum results in a campaign page. Only valid with `campaign-id`; from `1` to `25`, default `25`. |

`status` and `systemData` are always included. Do not include them in `fields`; the request succeeds but includes an `invalid-fields` warning.

**Sample Request**

```bash theme={null}
curl -L -X GET \
  'https://api.criteo.com/experimental/retail-media/diagnostics/line-item-checks?line-item-id=112233445566778899&fields=context,issues' \
  -H 'Accept: application/json' \
  -H 'Authorization: Bearer <MY_ACCESS_TOKEN>'
```

### Response Attributes

Each result is in `data[].attributes`.

| Attribute | Type | Description |
| - | - | - |
| `status` | string | `CanFullyServe`, `CanPartiallyServe`, `CannotServe`, or `Unknown`. Always included. |
| `systemData` | object | Check and source timestamps: `checkTime`, `lineItemCreatedTime`, and `lineItemUpdatedTime`. Always included. |
| `context` | object | IDs and types associated with the check: `accountId`, `campaignId`, `retailerId`, `lineItemId`, `campaignType`, and `buyType`. |
| `parameters` | object | Name/value pairs used while evaluating rules. |
| `issues` | array | Issues found in the line item's configuration. Each issue includes `ruleId`, `ruleName`, `code`, `severity`, `tags`, `format`, `outputParameters`, `message`, `id`, and optional `parentId`. |

### Status Values

| Status | Description |
| - | - |
| `CanFullyServe` | The line item is correctly configured, with no identified issues that limit serving. |
| `CanPartiallyServe` | The line item can serve in some contexts, but one or more issues limit serving. |
| `CannotServe` | Configuration issues prevent the line item from serving. |
| `Unknown` | The check could not complete. Inspect `warnings` and retry later. |

For campaign requests, `metadata` contains `cursor` (the next page cursor, or `null`), `limit`, and `count`.

**Sample Response** — `200 OK`

```json theme={null}
{
  "data": [
    {
      "attributes": {
        "status": "CannotServe",
        "systemData": {
          "checkTime": "2026-10-21T14:30:00Z",
          "lineItemCreatedTime": "2026-10-01T09:00:00Z",
          "lineItemUpdatedTime": "2026-10-21T14:00:00Z"
        },
        "context": {
          "accountId": "12345",
          "campaignId": "99887766",
          "retailerId": "54321",
          "lineItemId": "112233445566778899",
          "campaignType": "OnsiteDisplay",
          "buyType": "Auction"
        },
        "issues": [
          {
            "ruleId": "creative-required",
            "ruleName": "Creative required",
            "code": "no-approved-creative",
            "severity": "Error",
            "tags": ["creative"],
            "format": "No approved creative is associated with this line item.",
            "outputParameters": {},
            "message": "No approved creative is associated with this line item.",
            "id": 1,
            "parentId": null
          }
        ]
      }
    }
  ],
  "warnings": []
}
```

### Result Availability

An unexpected evaluation failure returns `200 OK` with `status` set to `Unknown` and a `result-unavailable` warning. Treat this as an incomplete result and retry later; do not interpret it as confirmation that the line item can serve.

### Errors

| HTTP status | Code | Description |
| - | - | - |
| `400` | `request-invalid` | Both or neither selector was supplied, or campaign pagination is invalid. |
| `400` | `invalid-fields` | `fields` contains an unsupported or duplicate optional field. |
| `401` | — | The caller is not authenticated. |
| `403` | `not-authorized` | The resource does not exist, has an invalid ID, or the caller cannot access it. |