---
title: aggregates-custom-events
product: vercel
url: /docs/rest-api/web-analytics/aggregates-custom-events
canonical_url: "https://vercel.com/docs/rest-api/web-analytics/aggregates-custom-events"
last_updated: 2026-10-05
type: reference
prerequisites:
  []
related:
  - /docs/rest-api
summary: Learn about aggregates-custom-events on Vercel.
install_vercel_plugin: npx plugins add vercel/vercel-plugin
---

# Aggregates custom events

```http
GET /v1/query/web-analytics/events/aggregate
```

Counts custom events on a project, within the requested date range. Results are either aggregated or broken down over time. Results can additionally be broken down by one dimension, and filtered by multiple dimensions.

## Authentication

**bearerToken**: HTTP bearer

## Query parameters

| Name | Type | Required | Description |
|---|---|---|---|
| `projectId` | string | Yes | The project identifier or the project name |
| `by` | array | Yes | Up to two dimensions used to break down results.  At most one time granularity is allowed: hour, day, week, month, year.  Other dimensions: country, deviceType, environment, requestPath, referrerHostname, osName, browserName, route, utmSource, utmMedium, utmCampaign, utmContent, utmTerm, eventName.  JSON dimensions: flags, eventData. Used bare, they break down results by key, for example flags returns one group per flag name. With a key, they break down results by that key's value, for example eventData/plan. Wrap keys containing characters other than letters, digits, and underscores in single quotes, for example flags/'my-flag'. |
| `since` | object | Yes | Timestamp in milliseconds, or a valid Date string.  Selects data from (including) this date and time. Will be adjusted according to the desired time granularity. |
| `until` | object | Yes | Timestamp in milliseconds, or a valid Date string.  Selects data until (including) this date. Will be adjusted according to the desired time granularity. |
| `limit` | integer. min: 1; max: 100; default: 10 | No | Number of distinct results, default to 10. Other results are grouped into "Others" group. |
| `filter` | string. maxLength: 2048 | No | OData-compliant filter. Encode the value when sending it in a URL.  Allows filtering on one or multiple dimensions. By default, filters for production environment only.  Supported dimensions: country, deviceType, environment, requestPath, referrerHostname, osName, browserName, route, utmSource, utmMedium, utmCampaign, utmContent, utmTerm, eventName.  JSON dimensions filtered by key: flags/<name>, eventData/<property>, for example eventData/plan eq 'pro'. Wrap keys containing characters other than letters, digits, and underscores in single quotes, for example flags/'my-flag' eq 'true'.  Supported operations include eq, ne, in, and logical operators and, or, not with parentheses. Functions such as startswith are supported by the OData parser. |
| `teamId` | string | No | The Team identifier to perform the request on behalf of. |
| `slug` | string | No | The Team slug to perform the request on behalf of. |


## Example request

### TypeScript

```typescript
const response = await fetch('https://api.vercel.com/v1/query/web-analytics/events/aggregate?projectId=string&by=[]&since=value&until=value&limit=123&filter=string&teamId=string&slug=string', {
  method: 'GET',
  headers: {
    'Authorization': 'Bearer YOUR_ACCESS_TOKEN',
    'Content-Type': 'application/json',
  },
});

const data = await response.json();
console.log(data);
```

### Next.js

```typescript
'use server';

export async function callEndpoint() {
  const response = await fetch('https://api.vercel.com/v1/query/web-analytics/events/aggregate?projectId=string&by=[]&since=value&until=value&limit=123&filter=string&teamId=string&slug=string', {
    method: 'GET',
    headers: {
      'Authorization': `Bearer ${process.env.VERCEL_ACCESS_TOKEN}`,
      'Content-Type': 'application/json',
    },
    next: { revalidate: 3600 }
  });

  if (!response.ok) {
    throw new Error('Request failed');
  }

  return response.json();
}
```

### cURL

```bash
curl -X GET 'https://api.vercel.com/v1/query/web-analytics/events/aggregate?projectId=string&by=[]&since=value&until=value&limit=123&filter=string&teamId=string&slug=string' \
  -H 'Authorization: Bearer YOUR_ACCESS_TOKEN' \
  -H 'Content-Type: application/json'
```

## Example response

```json
{
  "data": [
    {
      "browserName": "Example Name",
      "country": "string",
      "deviceType": "string",
      "environment": "string",
      "eventData": "string",
      "eventName": "Example Name",
      "flags": "string",
      "osName": "Example Name",
      "projectId": "example_id",
      "projectName": "Example Name",
      "referrerHostname": "Example Name",
      "requestHostname": "Example Name",
      "requestPath": "string",
      "route": "string",
      "utmCampaign": "string",
      "utmContent": "string",
      "utmMedium": "string",
      "utmSource": "string",
      "utmTerm": "string",
      "visitorId": "example_id",
      "timestamp": "2024-01-01T00:00:00Z"
    }
  ],
  "query": {
    "filter": "string",
    "groupBy": [],
    "limit": "123",
    "since": "string",
    "until": "string"
  },
  "version": "123"
}
```

## Responses

### 200: No description

Content-Type: `application/json`

```json
{
  "type": "object",
  "required": [
    "data",
    "query",
    "version"
  ],
  "properties": {
    "data": {
      "oneOf": [
        {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "timestamp"
            ]
          }
        },
        {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "browserName",
              "country",
              "deviceType",
              "environment",
              "eventData",
              "eventName",
              "flags",
              "osName",
              "projectId",
              "projectName",
              "referrerHostname",
              "requestHostname",
              "requestPath",
              "route",
              "utmCampaign",
              "utmContent",
              "utmMedium",
              "utmSource",
              "utmTerm",
              "visitorId"
            ]
          }
        }
      ]
    },
    "query": {
      "type": "object",
      "required": [
        "limit",
        "since",
        "until"
      ],
      "properties": {
        "filter": {
          "type": "string"
        },
        "groupBy": {
          "type": "array",
          "items": {}
        },
        "limit": {
          "type": "number"
        },
        "since": {
          "type": "string"
        },
        "until": {
          "type": "string"
        }
      }
    },
    "version": {
      "type": "number"
    }
  }
}
```

### 400: One of the provided values in the request query is invalid.

### 401: The request is not authorized.

### 402: No description

### 403: You do not have permission to access this resource.

### 404: No description

### 410: No description

### 503: No description

---

## Related

- [web-analytics endpoints](/docs/rest-api#web-analytics)

- [REST API overview](/docs/rest-api)

- [OpenAPI spec](https://vercel.com/openapi.json) (machine-readable, all endpoints)

---

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