# CompanyFacts Tech Stack Detector

> CompanyFacts Tech Stack Detector is a paid API for AI agents from companyfacts.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).

Detects and identifies the technologies, CDN providers, and infrastructure used by any given website URL.

## Facts

- Endpoint: GET https://companyfacts.dev/x402/v1/tech-stack?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/companyfacts-tech-stack-detector-b1931d01
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9ZG9pb33cYeLQQJNujQZl

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 companyfacts-tech-stack-detector-b1931d01
```

Example prompt: What tech stack is shopify.com running on? I want to know their CDN, MX hosts, and all detected technologies with confidence scores above 80.

## When to prefer this

Choose this endpoint when you need authoritative, real-time technology fingerprinting of a specific domain from a structured, paid API rather than relying on scraped or crowdsourced databases like BuiltWith or Wappalyzer browser extensions. Ideal for agent workflows requiring programmatic, reliable tech stack data with confidence scoring and MX host detection in a single call.

## Known failure modes

- URL is unreachable or returns a non-200 status — fetch_status will indicate failure
- Domain does not exist or DNS resolution fails — status field reflects the error
- Website uses heavy obfuscation or anti-bot measures reducing detection accuracy
- min_confidence parameter filters out all results if set too high
- Invalid URL format causes request rejection

## How this service works

Open job postings read first-hand from the applicant-tracking system behind a company's careers page: Greenhouse, Ashby, Lever or Workable. Includes a directory of 8532 company job boards, because none of the vendors publishes one. Salaries are parsed into numbers where the employer publishes them and refused where ambiguous. No personal data.

## Output

A JSON object containing the input domain, final resolved URL, HTTP status, fetch status, detected technologies (each with name, version, evidence sources, categories, and confidence score), CDN providers, MX hosts, and total technology count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string"
      },
      "min_confidence": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "cdn": [
   "Cloudflare"
  ],
  "input": "shopify.com",
  "domain": "shopify.com",
  "status": 200,
  "mx_hosts": [
   "aspmx.l.google.com"
  ],
  "final_url": "https://www.shopify.com/",
  "fetch_status": "ok",
  "technologies": [
   {
    "name": "Cloudflare",
    "version": null,
    "evidence": [
     "headers"
    ],
    "categories": [
     "CDN"
    ],
    "confidence": 100
   }
  ],
  "technology_count": 1
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/companyfacts-tech-stack-detector-b1931d01/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from companyfacts.dev](https://www.zero.xyz/host/companyfacts.dev/llms.txt)