> For the complete documentation index, see [llms.txt](https://developer.barchart.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.barchart.com/market-replay-docs/getting-started/javascript-example.md).

# JavaScript example

Use JavaScript when you want to call Market Replay from Node.js or a serverless function.

This example uses the built-in `fetch` API.

## What this example does

It shows how to:

* authenticate with `username` and `password`
* call the minute endpoint
* parse the CSV response
* turn rows into structured objects

## Example script

```javascript
const baseUrl = "https://historical.aws.barchart.com/historical/queryminutes.ashx";

const params = new URLSearchParams({
  username: process.env.BARCHART_USERNAME || "YOUR_USERNAME",
  password: process.env.BARCHART_PASSWORD || "YOUR_PASSWORD",
  symbol: "AAPL",
  start: "200902030900",
  end: "200902031200",
  interval: "5"
});

const response = await fetch(`${baseUrl}?${params.toString()}`);
const text = await response.text();

const rows = text
  .trim()
  .split("\n")
  .filter(Boolean)
  .map((line) => {
    const [timestamp, tradingDay, open, high, low, close, volume] = line.split(",");
    return {
      timestamp,
      tradingDay,
      open: Number(open),
      high: Number(high),
      low: Number(low),
      close: Number(close),
      volume: Number(volume)
    };
  });

console.log(`Returned ${rows.length} rows`);
console.log(rows.slice(0, 3));
```

## Sample output shape

Minute data rows use this format:

```
YYYY-MM-DD HH:MM,TRADING_DAY,OPEN,HIGH,LOW,CLOSE,VOLUME
```

## Use environment variables

Keep credentials out of source control.

```javascript
const params = new URLSearchParams({
  username: process.env.BARCHART_USERNAME,
  password: process.env.BARCHART_PASSWORD,
  symbol: "AAPL",
  maxrecords: "10",
  order: "desc"
});
```

{% hint style="warning" %}
Do not put credentials in browser-side code. Use JavaScript on the server side.
{% endhint %}

## Change the endpoint

Swap the request URL and parsing logic based on the dataset:

* `queryticks.ashx` for tick data
* `queryminutes.ashx` for minute bars
* `queryeod.ashx` for end-of-day bars
* `queryevents.ashx` for splits, dividends, and earnings

## Next steps

* Start with [Authentication](/market-replay-docs/reference/authentication.md)
* Use [Quickstart](/market-replay-docs/getting-started/quickstart.md) for the first request flow
* Compare with [Python example](/market-replay-docs/getting-started/python-example.md)
* Copy from [curl examples](/market-replay-docs/getting-started/curl-examples.md)
* Use [Query parameter cheat sheet](/market-replay-docs/reference/query-parameter-cheat-sheet.md)


---

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## Querying This Documentation
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Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://developer.barchart.com/market-replay-docs/getting-started/javascript-example.md?ask=<question>&goal=<endgoal>
```

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