# Tech Detect — Web Technology Stack Fingerprinter

> Tech Detect — Web Technology Stack Fingerprinter is a paid API for AI agents from stack.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-13).

Given a domain or URL, returns the detected technology stack with confidence scores and evidence for each identified technology.

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/vercel?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tech-detect-web-technology-stack-fingerprinter-fca79a29
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ENFln9BS2cpwRvg0823fb

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 tech-detect-web-technology-stack-fingerprinter-fca79a29 -d '<json body>'
```

Example prompt: What's the tech stack behind stripe.com — frameworks, CDN, analytics, everything you can detect, with confidence scores for each hit?

## When to prefer this

Choose this endpoint when you need per-call, no-signup technology detection with explicit confidence and evidence per technology, especially in automated pipelines where you want pay-as-you-go pricing via USDC over x402. It supports incremental scanning via the optional 'previous' payload to diff stack changes over time, making it ideal for monitoring use cases. Prefer it over Wappalyzer-style browser extensions or BuiltWith when you need programmatic, agent-native access without API key management.

## Known failure modes

- Domain unreachable or returns non-200 response — detection fails with an error
- Private/intranet domains that are not publicly accessible cannot be scanned
- Bot-blocking or anti-scraping measures may prevent fingerprinting
- Obfuscated or minified assets may reduce detection confidence or miss technologies
- Malformed URL input returns validation error

## How this service works

Purpose-bound Vercel observation (hosting) using the existing fresh Stack-Monitor. Returns stack_vercel_decision, direct versus inferred status, evidence, optional version difference against a caller-owned baseline and reusable snapshot. Missing fingerprints do not prove absence. No background scheduling, CVE, compatibility or installed-extension inventory. Existing outbound safeguards remain in the injected motor. One public HTTPS root domain, up to150 baseline technologies; 9s timeout.

## Output

A structured list of detected technologies, each with a name, category (e.g. framework, CDN, analytics), version if detectable, a confidence score, and supporting evidence. May include frontend libraries, backend stacks, hosting providers, CMS platforms, analytics tools, and more.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048
  },
  "previous": {
   "type": "object",
   "required": [
    "observed_at",
    "technologies"
   ],
   "properties": {
    "observed_at": {
     "type": "string",
     "maxLength": 40
    },
    "technologies": {
     "type": "array",
     "items": {
      "type": "object",
      "required": [
       "name",
       "category",
       "version"
      ],
      "properties": {
       "name": {
        "type": "string",
        "maxLength": 150
       },
       "version": {
        "type": [
         "string",
         "null"
        ],
        "maxLength": 80
       },
       "category": {
        "type": "string",
        "maxLength": 80
       }
      },
      "additionalProperties": false
     },
     "maxItems": 150
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tech-detect-web-technology-stack-fingerprinter-fca79a29/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stack.halowerk.com](https://www.zero.xyz/host/stack.halowerk.com/llms.txt)