# Tech Detect — GA4 Technology Stack Detection

> Tech Detect — GA4 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 whether a given domain uses Google Analytics 4 (GA4) and returns confidence scores and evidence for the technology hit, paid per call via x402 USDC.

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/ga4?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-ga4-technology-stack-detection-5e807e63
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UcD0QMvs6fP2CPmaudnLe

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-ga4-technology-stack-detection-5e807e63 -d '<json body>'
```

Example prompt: Can you check whether stripe.com is running Google Analytics 4 — I want confidence scores and evidence for any GA4 hits you find?

## When to prefer this

Choose this endpoint when you need fast, pay-as-you-go technology detection for a specific domain with no API key or subscription required. It is especially suited for GA4-specific detection tasks, one-off competitive intelligence lookups, or enrichment pipelines where you only pay for calls made. Prefer it over full-crawl solutions when you need a lightweight, per-domain signal with confidence scoring rather than a broad technology audit.

## Known failure modes

- Invalid or unreachable URL returns an error or empty technology list
- Payment failure over x402 results in 402 response and no data returned
- Domain with heavy bot protection may yield low-confidence or incomplete results
- Malformed URL input exceeding 2048 characters rejected by schema validation
- If previous observations array exceeds 150 items the request will be 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 structured technology detection result for the queried domain, including whether GA4 is present, a confidence score, supporting evidence for the detection, technology category, and version information where available.

## 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-ga4-technology-stack-detection-5e807e63/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)