# BuiltWith Technology Profiler (Free Tier) via Locus x402

> BuiltWith Technology Profiler (Free Tier) via Locus x402 is a paid API for AI agents from builtwith.x402.paywithlocus.com, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-14).

Profiles a website's technology stack using BuiltWith data, detecting frameworks, analytics tools, CDNs, CMSs, and hundreds of other technologies used by a given domain.

## Facts

- Endpoint: POST https://builtwith.x402.paywithlocus.com/builtwith/free
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/builtwith-technology-profiler-free-tier-via-locus-x402-c5b69297
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xtpjfj1ntb1la8HTdLg-y

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability builtwith-technology-profiler-free-tier-via-locus-x402-c5b69297 -d '<json body>'
```

Example prompt: What tech stack is stripe.com running on? I want to know their CMS, frontend framework, analytics tools, and any other notable technologies BuiltWith can detect.

## When to prefer this

Use this endpoint when you need to quickly identify what technologies a specific website uses, especially for competitive intelligence, sales prospecting, or technical due diligence. Prefer this free-tier endpoint for single-domain lookups at low cost ($0.015 USDC). Choose BuiltWith over manual inspection when you need structured, categorized tech-stack data across hundreds of technology categories without crawling the site yourself.

## Known failure modes

- Unknown or uncrawled domain returns empty or sparse data object
- Invalid domain format causes request failure
- Domain has no detectable technologies (minimal JS/static site)
- Service temporarily unavailable returns non-success response
- Payment settlement failure via x402 protocol blocks the request

## How this service works

Technology profiling for websites — detect tech stacks, find sites using specific technologies, discover domain relationships, trends, and competitive intelligence across 100M+ websites.

## Output

Returns a JSON object containing detected technologies for the queried domain, including categories such as CMS, frontend frameworks, analytics platforms, CDN providers, advertising tools, and other third-party integrations, drawn from BuiltWith's database of 100M+ websites. Also includes payment metadata (settled USDC amount) and a request tracking ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "LOOKUP": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "payment": {
   "scheme": "exact",
   "settledUsdc": "0.001000",
   "authorizedMaxUsdc": "0.001000"
  },
  "request": {
   "id": "00000000-0000-4000-8000-000000000000",
   "statusUrl": "/requests/00000000-0000-4000-8000-000000000000"
  },
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/builtwith-technology-profiler-free-tier-via-locus-x402-c5b69297/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from builtwith.x402.paywithlocus.com](https://www.zero.xyz/host/builtwith.x402.paywithlocus.com/llms.txt)