# Tech Detect — Pay-Per-Call Technology Stack Detection

> Tech Detect — Pay-Per-Call Technology Stack Detection 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 and identifies the technology stack of a given domain URL, returning confidence scores and evidence for each detected technology.

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/yoast?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-pay-per-call-technology-stack-detection-b69d2181
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xVRUJA9awHdehVe78lRJ6

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-pay-per-call-technology-stack-detection-b69d2181 -d '<json body>'
```

Example prompt: What's the full technology stack of yoast.com? I want confidence scores and evidence for every technology detected — CMS, frontend frameworks, analytics, CDN, whatever you can find.

## When to prefer this

Choose this endpoint when you need pay-as-you-go technology stack detection with no API key or signup required, especially for one-off or infrequent lookups billed in USDC via x402. It is well-suited for agents that need to fingerprint arbitrary domains on demand and want per-detection confidence scoring with evidence, rather than a subscription-based bulk crawler.

## Known failure modes

- Domain is unreachable or returns non-200 responses — detection may be incomplete or fail entirely
- Private/intranet domains cannot be scanned from external infrastructure
- Heavily obfuscated or minified stacks may yield low confidence or missed detections
- Invalid URL format returns a validation error
- Rate limiting or bot protection on the target domain may block fingerprinting probes

## How this service works

Domain in, technology stack out. Confidence and evidence for every hit. Pay per call in USDC over x402. No signup, no API key.

## Output

A structured list of detected technologies for the target domain, each with a name, category (e.g. CMS, JavaScript framework, CDN), version where detectable, confidence score, and supporting evidence for the detection hit.

## 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-pay-per-call-technology-stack-detection-b69d2181/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)