# SiteCheck Web Intel – Security Headers Checker

> SiteCheck Web Intel – Security Headers Checker is a paid API for AI agents from api.webintel-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-25).

Fetches a domain's HTTP response headers and scores them against security best practices, reporting which headers are present or missing.

## Facts

- Endpoint: GET https://api.webintel-api.workers.dev/api/security/security-headers?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-25
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-web-intel-security-headers-checker-d4e7d20f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-OMcbL6dQeUohKSEzcBsV

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 sitecheck-web-intel-security-headers-checker-d4e7d20f
```

Example prompt: Can you check the security headers for wikipedia.org and tell me which ones are missing and what score it gets?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call audit of a domain's HTTP security headers without setting up any account or API key. It is ideal for one-off checks, automated security scanning pipelines, or compliance reporting where you need a scored breakdown of present vs. missing headers like CSP, HSTS, and X-Content-Type-Options.

## Known failure modes

- Domain does not exist or is unreachable — request may fail or return error
- Domain redirects indefinitely — final URL may differ significantly
- Server returns non-standard headers that don't map to expected security header names
- Rate limiting or network timeouts from the target domain
- Invalid domain format provided as input

## How this service works

Checks the live HTTP response headers of a site's home page (one GET, https) for Content-Security-Policy, Strict-Transport-Security, X-Content-Type-Options, X-Frame-Options, Referrer-Policy, Permissions-Policy and Cross-Origin-Opener-Policy. Returns present/missing headers with their values and a score out of 7. It does not judge the quality of the values.

## Output

Returns a JSON object with a numeric security score and max possible score, the domain checked, the final resolved URL, HTTP status, a list of present headers with their values, a list of missing recommended security headers, and the timestamp of the check.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "description": "Domain name such as wikipedia.org (required)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "score": 1,
  "domain": "wikipedia.org",
  "source": "https://wikipedia.org/",
  "missing": [
   "content-security-policy",
   "x-content-type-options"
  ],
  "present": {
   "strict-transport-security": "max-age=106384710; includeSubDomains; preload"
  },
  "finalUrl": "https://www.wikipedia.org/",
  "maxScore": 7,
  "checkedAt": "2026-10-23T09:38:33.527Z",
  "httpStatus": 200
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-web-intel-security-headers-checker-d4e7d20f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.webintel-api.workers.dev](https://www.zero.xyz/host/api.webintel-api.workers.dev/llms.txt)