# BuiltWith API

> BuiltWith returns website technology data and detection dates as a workflow and API.

BuiltWith returns technologies shown on a free profile, grouped in displayed order; provide a domain or company name. Get website technologies includes detection dates only when shown on the free profile; paid and historical details are excluded.

- Page: https://fous.com/tools/builtwith
- Handle: `@builtwith`
- Category: [Marketing](https://fous.com/tools/category/marketing)
- Source website: https://builtwith.com
- Last verified: Sep 29, 2026

## Methods

### Get website technologies

Operation `get_website_technologies`, version 1. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.

Get technologies shown in a website’s free BuiltWith profile, grouped in its displayed order. Company names are matched to a website using public search. Per-technology detection dates are included only when the free profile shows them; paid and historical details are excluded.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `website` | string | yes | `"Allbirds"` | Website domain or company name, for example shopify.com or Allbirds. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "website"
  ],
  "properties": {
    "website": {
      "type": "string",
      "description": "Website domain or company name, for example shopify.com or Allbirds.",
      "examples": [
        "Allbirds",
        "shopify.com"
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "website": "Allbirds"
    },
    {
      "website": "shopify.com"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `domain` | string | `"allbirds.com"` |  |
| `technologies` | array |  |  |
| `technologies[].type` | string | `"Analytics and Tracking"` |  |
| `technologies[].description` | string or null | `"Dynamic Yield, owned by Mastercard, is a platform that allows companies to rapidly create and A/B test personalized and` |  |
| `technologies[].last_detected` | string or null |  | YYYY-MM-DD when shown; otherwise null. |
| `technologies[].first_detected` | string or null |  | YYYY-MM-DD when shown; otherwise null. |
| `technologies[].technology_link` | string or null | `"https://trends.builtwith.com/analytics/Dynamic-Yield"` |  |
| `technologies[].technology_name` | string | `"Dynamic Yield"` |  |
| `website_used` | string | `"https://www.allbirds.com/"` | Website selected for the lookup. |
| `builtwith_page_link` | string | `"https://builtwith.com/allbirds.com"` |  |

**Example input**

```json
{
  "website": "Allbirds"
}
```

**Example output**

```json
{
  "domain": "allbirds.com",
  "technologies": [
    {
      "type": "Analytics and Tracking",
      "description": "Dynamic Yield, owned by Mastercard, is a platform that allows companies to rapidly create and A/B test personalized and optimized user experiences.",
      "last_detected": null,
      "first_detected": null,
      "technology_link": "https://trends.builtwith.com/analytics/Dynamic-Yield",
      "technology_name": "Dynamic Yield"
    },
    {
      "type": "Analytics and Tracking",
      "description": "Data collection and marketing monitoring tool.",
      "last_detected": null,
      "first_detected": null,
      "technology_link": "https://trends.builtwith.com/analytics/Elevar",
      "technology_name": "Elevar"
    },
    {
      "type": "Analytics and Tracking",
      "description": "A unified platform to send lifecycle, blast marketing, and transactional emails with real-time analytics, user segmentation, A/B testing and more.",
      "last_detected": null,
      "first_detected": null,
      "technology_link": "https://trends.builtwith.com/analytics/Iterable",
      "technology_name": "Iterable"
    }
  ],
  "website_used": "https://www.allbirds.com/",
  "builtwith_page_link": "https://builtwith.com/allbirds.com"
}
```

## Quick start

Replace `YOUR_API_KEY` with a Fous API key. To create one, open Developers at the bottom of Fous Studio, turn on Developer mode, then go to API keys (https://app.fous.com/keys). Change the values in `input` to run the same tool on new data.

```bash
curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 180 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@builtwith",
  "visibility": "public",
  "operation": "get_website_technologies",
  "version": 1,
  "input": {
    "website": "Allbirds"
  },
  "response": {
    "format": "json"
  }
}'
```

```python
# Save as fous.py and run with python3 fous.py. No packages needed.
import json
import urllib.error
import urllib.request

api_key = "YOUR_API_KEY"

body = json.loads("{\n  \"api\": \"@builtwith\",\n  \"visibility\": \"public\",\n  \"operation\": \"get_website_technologies\",\n  \"version\": 1,\n  \"input\": {\n    \"website\": \"Allbirds\"\n  },\n  \"response\": {\n    \"format\": \"json\"\n  }\n}")
request = urllib.request.Request(
    "https://api.fous.com/v1/query",
    data=json.dumps(body).encode("utf-8"),
    headers={
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=180) as response:
        result = json.load(response)
except urllib.error.HTTPError as error:
    raise RuntimeError(f"HTTP {error.code}: {error.read().decode('utf-8', errors='replace')}") from error
if result.get("success") is False:
    raise RuntimeError(result.get("error", {}).get("message", "Request failed"))
print(json.dumps(result["data"]["output"], indent=2))
```

```typescript
// Save as fous.mts and run with npx tsx fous.mts.
const apiKey = "YOUR_API_KEY";

const response = await fetch("https://api.fous.com/v1/query", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  signal: AbortSignal.timeout(180_000),
  body: JSON.stringify({
  "api": "@builtwith",
  "visibility": "public",
  "operation": "get_website_technologies",
  "version": 1,
  "input": {
    "website": "Allbirds"
  },
  "response": {
    "format": "json"
  }
}),
});
type ApiResult = { success: boolean; data?: { output: unknown }; error?: { message: string } };
const result: ApiResult = await response.json();
if (!response.ok || result.success === false) {
  throw new Error(result.error?.message ?? `HTTP ${response.status}`);
}
if (!result.data) throw new Error("Missing API response data");
console.log(result.data.output);
```

## Use from an AI assistant

Connect this tool to Claude Code, Claude Desktop, Cursor, VS Code, Codex and any MCP client as its own MCP server. Each method is a typed tool whose arguments are the method’s input.

- Server URL: `https://api.fous.com/mcp/tools/builtwith`
- Authorization: `Authorization: Bearer <Fous API key>`

**Tools**

- `get_website_technologies`: Get website technologies. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.
- `fous_get_run`: the result of a run that was still going, by its `request_id`. Free.

Claude Code:

```bash
claude mcp add --scope user --transport http fous-builtwith https://api.fous.com/mcp/tools/builtwith --header "Authorization: Bearer ${FOUS_API_KEY:?Set FOUS_API_KEY to your Fous API key}"
```

To give the assistant every tool, connect `https://api.fous.com/mcp`: it finds one with `fous_search_tools` and runs it with `fous_run_tool`. Setup for other clients: https://fous.com/llms-full.txt.

## Use cases

- Review technologies shown on a company website profile
- Compare displayed technology stacks across company websites
- Check available technology detection dates

## FAQ

### Can I run it with my own inputs?

Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.

### Can I call this BuiltWith tool as an API?

Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.

### How much does it cost?

Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.

### Do I need a BuiltWith account?

No. You only need a Fous account.

### How current is the data?

Fous gets the data from builtwith.com when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.

### What technologies are shown on a website?

Get website technologies returns technologies shown in the free profile, grouped in displayed order.

### When were technologies first or last detected?

Get website technologies returns first and last detection dates when shown in the free profile; otherwise, those dates are null.

## Related

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- [Wayback Machine API](https://fous.com/tools/wayback-machine.md): Wayback Machine lets you explore archived websites, find the closest page capture to a past date, and review captures over time; the nearest capture may fall outside the requested period.
- [Have I Been Pwned API](https://fous.com/tools/have-i-been-pwned.md): Find public records of known data breaches.
- [Website Reader API](https://fous.com/tools/website-reader.md): Website Reader returns public-page content and company contacts (home page plus up to five relevant pages), and Westminster’s PeopleFirst link details with up to 2,000 text characters.
- [ICANN Lookup API](https://fous.com/tools/icann-lookup.md): Public domain registration lookup using ICANN registration data.
- [Google PageSpeed Insights API](https://fous.com/tools/google-pagespeed-insights.md): Check web page speed and quality on mobile and desktop.
- [Can I use API](https://fous.com/tools/can-i-use.md): Browser compatibility tables for web features.
- [All Marketing tools](https://fous.com/tools/category/marketing)