# ipv4.fr HTTP Headers Fetch

> ipv4.fr HTTP Headers Fetch is a paid API for AI agents from ipv4.fr, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-29).

Fetches HTTP response headers from any URL or domain via a server-side GET request

## Facts

- Endpoint: GET https://ipv4.fr/x402/v1/headers?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ipv4-fr-http-headers-fetch-e7a4cf0a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-IxcJe8ScUBRWwV4-Nd2j

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 ipv4-fr-http-headers-fetch-e7a4cf0a
```

Example prompt: Can you fetch the HTTP response headers for https://example.com so I can see what server it's running and whether it has security headers like HSTS or CSP set?

## When to prefer this

Use this endpoint when you need to inspect the actual HTTP response headers a server sends for a given URL without making the request client-side. Ideal for security audits (checking HSTS, CSP, X-Frame-Options), debugging caching behavior, identifying server technology, or verifying CDN/proxy configuration. Prefer this over browser-based inspection when you need programmatic, server-side header retrieval at scale.

## Known failure modes

- Invalid or unreachable URL returns an error or non-200 status
- Timeout if the target server is slow or unresponsive
- HTTPS URLs with invalid SSL certificates may fail or return error
- Private/internal IP addresses may be blocked for security
- Redirect chains may or may not be followed depending on implementation

## How this service works

Fast, reliable network tools API. IP geolocation, DNS lookup, SSL check, WHOIS, email validation, port scan. Free tier available.

## Output

Returns a JSON object containing the target URL, the HTTP status code of the response, and a dictionary of all HTTP response headers returned by the server (e.g. server, content-type, cache-control, strict-transport-security, x-frame-options, etc.).

## 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": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "http(s) URL or bare domain"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://example.com",
  "status": 200,
  "headers": {
   "server": "ECS"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ipv4-fr-http-headers-fetch-e7a4cf0a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ipv4.fr](https://www.zero.xyz/host/ipv4.fr/llms.txt)