# Security Headers Check Watch

> Security Headers Check Watch is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Monitors HTTP security headers for a given URL and reports whether they have changed since the last check, including which fields changed and their before/after values.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/http-headers
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/security-headers-check-watch-c5c4d0d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FuHs7psgXBegJpYD3r1IP

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 security-headers-check-watch-c5c4d0d0
```

Example prompt: Keep an eye on the HTTP security headers for https://example.com and let me know if anything changes compared to the last time you checked — tell me exactly which headers changed and what the before and after values were.

## When to prefer this

Use this endpoint when you need to detect changes in HTTP security headers over time for a specific URL, rather than just retrieving the current state. It is ideal for scheduled monitoring workflows where you want to be alerted to regressions, improvements, or any drift in security posture. Prefer this over a one-shot security headers check when you need change detection with before/after field-level diffs and historical comparison.

## Known failure modes

- URL is unreachable or returns a non-HTTP response, resulting in an error or incomplete headers data
- No previous result exists for the URL (first call), so changed will be false with no diff
- Stored previous result has expired after 90 days, resetting the comparison baseline
- Invalid or malformed URL input causing a request failure
- Rate limiting or payment issues preventing the check from running

## How this service works

Change watch for security headers check: runs the check and compares it with the result from your previous call for the same url (kept 90 days), returning the current answer, changed true/false, exactly which fields changed with before/after values, and when it was last seen. Call it on a schedule to be told when http security headers check for a website changes. $0.01 per check.

## Output

Returns the current HTTP security headers check result, a boolean indicating whether anything changed since the last call for the same URL (stored up to 90 days), a list of exactly which header fields changed with their before and after values, and the timestamp of when the previous result was last seen.

## 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",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/security-headers-check-watch-c5c4d0d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)