---
title: Querying Workers Analytics Engine from a Worker · Cloudflare Analytics docs
description: If you want to access Analytics Engine data from within a Worker
  you can use fetch to access the SQL API. The API can return JSON data that is
  easy to interact with in JavaScript.
lastUpdated: 2025-10-01T10:02:32.000Z
chatbotDeprioritize: false
source_url:
  html: https://developers.cloudflare.com/analytics/analytics-engine/worker-querying/
  md: https://developers.cloudflare.com/analytics/analytics-engine/worker-querying/index.md
---

If you want to access Analytics Engine data from within a Worker you can use `fetch` to access the SQL API. The API can return JSON data that is easy to interact with in JavaScript.

## Authentication

In order that your Worker can authenticate with the API you will need your account ID and an API token.

* Your 32 character account ID can be obtained from the Cloudflare dashboard.
* An API token can also be generated in the dashboard. Refer to the [SQL API docs](https://developers.cloudflare.com/analytics/analytics-engine/sql-api/#authentication) for more information on this.

We recommend storing the account ID as an environment variable and the API token as a secret in your worker. This can be done through the dashboard or through Wrangler. Refer to the [Workers documentation](https://developers.cloudflare.com/workers/configuration/environment-variables/) for more details on this.

## Querying

Use the JavaScript `fetch` API as follows to execute a query:

```js
const query = "SELECT * FROM my_dataset";
const API = `https://api.cloudflare.com/client/v4/accounts/${env.ACCOUNT_ID}/analytics_engine/sql`;
const response = await fetch(API, {
  method: "POST",
  headers: {
    Authorization: `Bearer ${env.API_TOKEN}`,
  },
  body: query,
});
const responseJSON = await response.json();
```

The data will be returned in the format described in the [FORMAT](https://developers.cloudflare.com/analytics/analytics-engine/sql-reference/statements/#json) section of the documentation, allowing you to extract meta information about the names and types of returned columns in addition to the data itself and a row count.

## Example Worker

The following is a sample Worker which executes a query against a dataset of weather readings and displays minimum and maximum values for each city.

### Environment variable setup

First the environment variables are set up with the account ID and API token.

The account ID is set in the [Wrangler configuration file](https://developers.cloudflare.com/workers/wrangler/configuration/):

* wrangler.jsonc

  ```jsonc
  {
    "$schema": "./node_modules/wrangler/config-schema.json",
    "vars": {
      "ACCOUNT_ID": "<account_id>"
    }
  }
  ```

* wrangler.toml

  ```toml
  [vars]
  ACCOUNT_ID = "<account_id>"
  ```

The API\_TOKEN can be set as a secret, using the wrangler command line tool, by running the following and entering your token string:

```sh
npx wrangler secret put API_TOKEN
```

### Worker script

The worker script itself executes a query and formats the result:

```js
export default {
  async fetch(request, env) {
    // This worker only responds to requests at the root.
    if (new URL(request.url).pathname != "/") {
      return new Response("Not found", { status: 404 });
    }


    // SQL string to be executed.
    const query = `
            SELECT
                blob1 AS city,
                max(double1) as max_temp,
                min(double1) as min_temp
            FROM weather
            WHERE timestamp > NOW() - INTERVAL '1' DAY
            GROUP BY city
            ORDER BY city`;


    // Build the API endpoint URL and make a POST request with the query string
    const API = `https://api.cloudflare.com/client/v4/accounts/${env.ACCOUNT_ID}/analytics_engine/sql`;
    const queryResponse = await fetch(API, {
      method: "POST",
      headers: {
        Authorization: `Bearer ${env.API_TOKEN}`,
      },
      body: query,
    });


    // The API will return a 200 status code if the query succeeded.
    // In case of failure we log the error message and return a failure message.
    if (queryResponse.status != 200) {
      console.error("Error querying:", await queryResponse.text());
      return new Response("An error occurred!", { status: 500 });
    }


    // Read the JSON data from the query response and render the data as HTML.
    const queryJSON = await queryResponse.json();
    return new Response(renderResponse(queryJSON.data), {
      headers: { "content-type": "text/html" },
    });
  },
};


// renderCity renders a table row as HTML from a data row.
function renderCity(row) {
  return `<tr><td>${row.city}</td><td>${row.min_temp}</td><td>${row.max_temp}</td></tr>`;
}


// renderResponse renders a simple HTML table of results.
function renderResponse(data) {
  return `<!DOCTYPE html>
<html>
    <body>
        <table>
            <tr><th>City</th><th>Min Temp</th><th>Max Temp</th></tr>
            ${data.map(renderCity).join("\n")}
        </table>
    </body>
<html>`;
}
```
