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

# Inspect source changes — HTTP

> Investigate source-level changes between a reference run and the selected run.

Investigate source-level changes between a reference run and the selected run.

**Method:** `GET`

**Path:** `/projects/{project_id}/runs/{run_id}/attribute-drift`

Use the HTTP base for your authorized environment and an `Authorization: Bearer` header. See [authentication](/developers/guides/04-authentication) and [HTTP setup](/developers/guides/06-http-quickstart).

## Parameters

This table covers the standard read profile. It excludes internal application routes and advanced analysis controls.

| Name | Location | Type | Required | Default | Meaning |
| - | - | - | - | - | - |
| `project_id` | path | string | Yes | — | Project ID from list\_projects. Select the project in the intended workspace and environment. |
| `run_id` | path | string | Yes | — | Run ID from list\_runs for this project. Use the exact returned value and check readiness before reading measurements. |
| `aggregation_level` | query | string | No | `"domain"` | domain requests source-domain results; url requests individual-page results. Keep the same reporting unit when comparing measurements. |
| `group_by` | query | string | No | `null` | JSON-encoded array. Split results into rows by the requested dimensions. Check both filters\_applied.group\_by and each row’s group\_by\_values before labeling the groups. |
| `filters` | query | string | No | `null` | JSON-encoded array. Select measured answers with objects containing dimension and values. Use labels from list\_dimension\_options; inspect returned warnings for filters that were not applied. |
| `reference` | query | string | No | `null` | JSON-encoded object. Choose the comparison run: previous\_run, first\_run, or specific\_run. For specific\_run, include run\_id. The request’s run\_id is the checkpoint. |
| `subject` | query | string | No | `null` | JSON-encoded object. Choose sources with kind: leaderboard, all, owned, or specified. For specified, provide domains containing exact source keys for the requested reporting unit. |

## Request example

Set `IQRUSH_API_BASE` and `IQRUSH_ACCESS_TOKEN` through secure configuration. Replace project/run IDs and sample selections with values returned by your account. JSON objects and arrays are encoded as query strings.

```bash theme={null}
curl --fail-with-body --silent --show-error --get \
  --header "Authorization: Bearer ${IQRUSH_ACCESS_TOKEN}" \
  --header "Accept: application/json" \
  --data-urlencode aggregation_level=domain \
  --data-urlencode 'reference={"type":"previous_run"}' \
  --data-urlencode 'subject={"kind":"owned"}' \
  "${IQRUSH_API_BASE%/}/projects/${IQRUSH_PROJECT_ID}/runs/${IQRUSH_RUN_ID}/attribute-drift"
```

## Read the response

Returns source-level contrasts in data.domain\_details. share\_diff compares the checkpoint with the reference; its difference is checkpoint minus reference.

Use the returned significance and correction metadata. Preserve reference and checkpoint IDs. Do not infer direction from separate confidence bands alone.

### Fields to use

These selected fields explain the example and the result to preserve. Field presence depends on the response; this is not a complete response schema.

| Field | Meaning and use |
| - | - |
| `data.domain_details[].domain_or_url` | Source whose citation-share change is described. |
| `data.domain_details[].share_diff.value_a` | Reference-run value. |
| `data.domain_details[].share_diff.value_b` | Checkpoint-run value. |
| `data.domain_details[].share_diff.diff` | Checkpoint minus reference. Preserve the scale when displaying the change. |
| `data.domain_details[].share_diff.ci_diff` | Confidence interval on the difference, not on either individual estimate. |
| `data.domain_details[].share_diff.significant` | Returned significance result. It does not establish business impact or causation. |

Selected response fields from IQRush Dev. Lists are shortened and project/run IDs are placeholders; this is not the full response.

```json theme={null}
{
  "data_ready": true,
  "data": {
    "reference_type": "previous_run",
    "aggregation_level": "domain",
    "domain_details": [
      {
        "domain_or_url": "colorescience.com",
        "share_diff": {
          "value_a": 0.0335164004223577,
          "value_b": 0.026726239624239412,
          "diff": -0.006790160798118287,
          "ci_diff": {
            "lower": -0.019421924882329574,
            "upper": 0.00255965226798446,
            "level": 0.95
          },
          "significant": false
        },
        "is_owned": true
      }
    ]
  }
}
```

Read the actual returned scope, counts, and interval levels before interpreting these fields.

MCP equivalent: [`attribute_drift`](/developers/tools/attribute_drift). Use the parameters and defaults on this page for HTTP.

## If the result is unavailable

Check HTTP status and the response’s `error` field before using data. A successful empty response does not establish a zero value. Preserve `not_available`, `not_available_reason`, `unavailable_reason`, and `linked` where returned. [Errors and recovery](/developers/guides/13-errors) shows observed examples.


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