# Tech Detect — Technology Stack Detection via x402

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

Analyzes a domain URL and returns its detected technology stack with confidence scores and evidence, billed per-call in USDC via x402 protocol

## Facts

- Endpoint: POST https://stack.halowerk.com/stack/articles/caddy?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-technology-stack-detection-via-x402-babbadcd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Huq2_FdQDRENzn_C_b1WM

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-via-x402-babbadcd -d '<json body>'
```

Example prompt: What technologies is stripe.com running — web server, framework, CDN, analytics, all of it? Give me confidence scores and evidence for each hit.

## When to prefer this

Choose this endpoint when you need pay-as-you-go technology stack detection without API key signup — ideal for one-off queries, agent workflows, or low-volume use cases billed in USDC via x402. Prefer it over subscription-based alternatives like BuiltWith or Wappalyzer when you want frictionless access with per-call pricing. The optional `previous` field makes it especially useful for change-detection workflows where you want to diff against a prior observation.

## Known failure modes

- Invalid or unreachable URL returns an error or empty technology list
- Domain blocks fingerprinting requests, leading to low or zero detections
- Version information unavailable for obfuscated or CDN-proxied sites
- Payment failure via x402 protocol results in 402 response and no data returned
- Malformed input schema (missing required fields) returns validation error

## 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 name, category (e.g. web server, CMS, JavaScript framework, analytics), version (if detectable), confidence score, and supporting evidence indicating how the technology was identified.

## 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-via-x402-babbadcd/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)