---
title: Volume spike event payload
description: Sent when a project's error volume spikes above its learned baseline.
url: https://docs.honeybadger.io/guides/integrations/payloads/volume_spike/
---

Sent when a project’s total error volume spikes above its learned baseline. See [Error volume anomaly detection](https://docs.honeybadger.io/guides/integrations/#error-volume-anomaly-detection) for details on how spikes are detected.

The subject of this event is the **project** (not an individual error), so the payload has no `fault`. Spike facts are in the `volume_spike` object:

* `observed` — the number of errors in the most recent one-hour window
* `baseline_median` — the project’s typical errors-per-hour (median of the trailing baseline window)
* `factor` — the observed volume as a multiple of the baseline median (e.g. `4.7` means 4.7× the typical rate); `null` when the baseline is near zero
* `z_score` — the modified z-score that triggered the alert
* `window_minutes` — the length of the observed window, in minutes

```json
{
  "event": "volume_spike",
  "message": "[Testy McTestFace] Errors are 4.7× your normal rate (412 in the last hour vs ~87/hr typical)",
  "project": {
    "id": 123321,
    "name": "Testy McTestFace",
    "created_at": "2017-08-30T12:54:33.156695Z",
    "disable_public_links": false,
    "pivotal_project_id": null,
    "asana_workspace_id": null,
    "token": "zzz111",
    "github_project": "spacely/testy-mctestface",
    "environments": [
      {
        "id": 68210,
        "project_id": 123321,
        "name": "production",
        "notifications": true,
        "created_at": "2017-09-05T06:10:19.057794Z",
        "updated_at": "2017-09-05T06:10:19.057794Z"
      }
    ],
    "owner": {
      "id": 1,
      "email": "ben@example.com",
      "name": "Spacely Sprockets"
    },
    "last_notice_at": "2023-10-30T19:29:08.000000Z",
    "earliest_notice_at": "2023-05-03T19:37:25.519130Z",
    "unresolved_fault_count": 102,
    "fault_count": 925,
    "active": true,
    "users": [
      {
        "id": 1,
        "email": "ben@example.com",
        "name": "Ben"
      }
    ],
    "sites": [],
    "team_id": 1
  },
  "volume_spike": {
    "observed": 412,
    "baseline_median": 87,
    "factor": 4.7,
    "z_score": 6.2,
    "window_minutes": 60
  }
}
```

---

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