# Tech Detect – Technology Stack Detection API (x402)

> Tech Detect – Technology Stack Detection API (x402) is a paid API for AI agents from stack.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-12).

Detects the technology stack (frameworks, libraries, CMS, analytics, etc.) used by a given domain, returning confidence scores and evidence for each detected technology, paid per call in USDC via x402.

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/mailchimp?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tech-detect-technology-stack-detection-api-x402-42f70fcb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TKflrx3J_v_hWqZ4rrX-8

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-technology-stack-detection-api-x402-42f70fcb -d '<json body>'
```

Example prompt: Can you detect what technology stack stack.halowerk.com is running — frameworks, CMS, analytics tools, anything you can find — and tell me the confidence level for each hit?

## When to prefer this

Choose this endpoint when you need fast, pay-per-call technology fingerprinting without signup or API key management. It is ideal for one-off lookups, agent workflows that need zero-friction access, or when you want to compare a current scan against a previous observation. Prefer it over subscription-based tech detection services (e.g. BuiltWith, Wappalyzer API) when cost-per-call economics and x402 micropayment compatibility are priorities.

## Known failure modes

- Domain unreachable or returns non-200 status — no technologies detected
- URL malformed or exceeds 2048 characters — validation error returned
- Domain blocks scraping/fingerprinting — partial or empty results
- Low-confidence detections for heavily obfuscated or custom-built stacks
- Rate limiting or payment failure via x402 protocol — request rejected

## 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

Returns a list of detected technologies for the given domain, each with a technology name, category (e.g. CMS, analytics, JavaScript framework), version if detectable, a confidence score, and supporting evidence strings. Optionally compares against a previously observed set to surface additions or removals.

## 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-technology-stack-detection-api-x402-42f70fcb/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)