# Tech Detect — Website Technology Stack Fingerprinter

> Tech Detect — Website 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).

Detects the technology stack (frameworks, libraries, CMSs, analytics tools, etc.) used by a given domain URL, returning each technology with confidence scores and supporting evidence.

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/umami?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-website-technology-stack-fingerprinter-ca5fc43f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wIu6Fyd2xnKtVsnlOEAly

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-website-technology-stack-fingerprinter-ca5fc43f -d '<json body>'
```

Example prompt: Can you detect the full technology stack for shopify.com — I want to know every framework, CMS, analytics tool, and library they use, along with confidence scores for each hit?

## When to prefer this

Choose this endpoint when you need per-call, pay-as-you-go technology stack detection with no API key or subscription required. Particularly well-suited for agents that need to enrich CRM records, conduct competitive analysis, or monitor stack changes on an ad-hoc basis. The optional 'previous' parameter makes it ideal for change-detection workflows. The x402 payment model makes it trivially embeddable in autonomous agent pipelines without credential management.

## Known failure modes

- Unresolvable or offline domain returns no technologies or an error
- Heavily obfuscated sites may yield low-confidence or sparse results
- Rate limiting or payment failure via x402 protocol results in HTTP 402 with no data
- Invalid URL format triggers input validation error
- Sites with aggressive bot-blocking may defeat fingerprinting probes

## How this service works

Purpose-bound Umami observation (analytics) using the existing fresh Stack-Monitor. Returns stack_umami_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

Returns a list of detected technologies for the given domain, each entry including the technology name, its category (e.g. 'CMS', 'Analytics', 'JavaScript Framework'), detected version if available, a confidence score, and evidence supporting the detection. Optionally compares against a previously observed snapshot to highlight changes.

## 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-website-technology-stack-fingerprinter-ca5fc43f/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)