# Testing and Debugging

The DSP provides several tools to test and debug campaign delivery.

## Debug mode

In non-production environments, or when debug mode is enabled, the bid response includes additional information:

```json
{
  "id": "response-uuid",
  "seatbid": [...],
  "ext": {
    "lineItems": [...],
    "eligibility": {
      "imp-id": [
        { "lineItemId": 123, "reason": null },
        { "lineItemId": 456, "reason": "targeting:Country:included (expected=[US], actual=FR)" }
      ]
    }
  }
}
```

### Enabling debug mode

* Set `test=1` in the OpenRTB bid request
* Add `nexx360_debug=1` as a URL query parameter on the publisher page

When no bid is returned in debug mode, the response also includes the full `bidRequest` object for inspection.

## Forced parameters

Forced parameters bypass normal eligibility checks, allowing you to test specific line items, creatives, and prices. They can be passed as URL query parameters on the publisher page (`site.page`) or via the OpenRTB request extension (`ext`).

Both hyphen and underscore variants are supported for URL parameters.

| URL parameter      | Underscore variant | Request ext field         | Description                                                  |
| ------------------ | ------------------ | ------------------------- | ------------------------------------------------------------ |
| `forced-line-item` | `forced_line_item` | `nexx360ForcedLineItemId` | Force a specific line item (bypasses all eligibility checks) |
| `forced-creative`  | `forced_creative`  | `nexx360ForcedCreativeId` | Force a specific creative within the forced line item        |
| `forced-price`     | `forced_price`     | `nexx360ForcedPrice`      | Override the bid price (in the target currency)              |

### What forced line item bypasses

When a line item is forced, the following checks are skipped:

* Status check (even `paused` line items will deliver)
* Date range validation
* Media type matching
* All targeting criteria
* Split targeting
* Delivery capping
* Delivery ratio / pacing

### URL parameter example

```
https://example.com/page?forced_line_item=12345&forced_creative=678&forced_price=5.5
```

### Request ext example

```json
{
  "ext": {
    "nexx360ForcedLineItemId": 12345,
    "nexx360ForcedCreativeId": 678,
    "nexx360ForcedPrice": 5.5
  }
}
```

{% hint style="info" %}
Request ext fields take priority over URL parameters when both are provided.
{% endhint %}

## Exchange test creative price override

Independently from the DSP forced parameters above, the exchange supports forcing a test creative at a specific CPM price. This is useful for verifying pricing flows end-to-end without involving the DSP.

| Endpoint type     | Parameter                                                                                                                                                    | Description                             |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------- |
| VAST / ReachTV    | `nexx360_force_creative_price=10` (URL query param)                                                                                                          | Force a Nexx360 test creative at CPM 10 |
| OpenRTB / Booster | `"nexx360_force_creative_price": 10` (in request `ext`) **or** `?nexx360_force_creative_price=10` appended to the publisher page URL (read from `site.page`) | Force a Nexx360 test creative at CPM 10 |

When set, the test creative is automatically enabled (no need to also pass `force_test_creative=1` or `nexx360_force_creative=1`).

{% hint style="info" %}
On the Booster / OpenRTB endpoints, if both the page URL and the body `ext` are provided, the body value wins.
{% endhint %}

## Use cases

| Scenario                                | Parameters                                                                                                                                             |
| --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Preview a campaign creative             | `forced_line_item` + `forced_creative`                                                                                                                 |
| Test at a specific price point          | `forced_line_item` + `forced_price`                                                                                                                    |
| Debug why a line item isn't bidding     | Enable `nexx360_debug=1` and check `ext.eligibility`                                                                                                   |
| Verify targeting setup                  | Enable debug mode and inspect rejection reasons                                                                                                        |
| Test exchange pricing at a specific CPM | `nexx360_force_creative_price=10` (VAST URL query, or publisher page URL for Booster/OpenRTB) or `"nexx360_force_creative_price": 10` in ext (OpenRTB) |


---

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