# Domain OSINT, TLS Certificate & Security Headers Recon

> Domain OSINT, TLS Certificate & Security Headers Recon is a paid API for AI agents from preflight.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Performs live DNS resolution, TLS certificate inspection, and HTTP security header grading for a given domain name.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/whois-lookup?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-domain-osint-tls-certificate-security-headers-1474ee47
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VjHnuCFwqkKWbU8iDthl0

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 preflight-agentdiet-dev-domain-osint-tls-certificate-security-headers-1474ee47
```

Example prompt: Can you do a full security recon on anthropic.com — I want to see its DNS resolution, TLS certificate issuer and expiry, and how its HTTP security headers grade out?

## When to prefer this

Choose this endpoint when you need a combined, live view of a domain's DNS resolution, TLS certificate health, and HTTP security posture in a single call. It is ideal for security due diligence on third-party vendors, monitoring certificate expiry for owned domains, or performing lightweight OSINT on infrastructure. Prefer it over manual DNS tools or separate certificate checkers when you want a unified, structured response from a single API call priced per use.

## Known failure modes

- Domain does not exist or fails DNS resolution — returns an error or empty DNS records
- Domain's HTTPS endpoint is unreachable — TLS and security header data may be unavailable
- Invalid or malformed domain input — returns a validation error
- Domain uses non-standard ports or configurations — may produce incomplete results
- Rate limiting or payment failure at the x402 layer — returns 402 Payment Required

## How this service works

Inspects live IPv4/IPv6 DNS resolution, TLS certificate issuer/expiry, and HTTP security grade. (Live x402 v2, IETF MPP & MCP endpoint at https://preflight.agentdiet.dev/v1/whois-lookup)

## Output

Returns live DNS resolution results (IPv4 and IPv6 addresses), TLS certificate metadata (issuer, expiry date, validity status), and an HTTP security header grade reflecting the presence and quality of headers like HSTS, CSP, X-Frame-Options, and similar security controls.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "domain"
 ],
 "properties": {
  "domain": {
   "type": "string",
   "minLength": 1,
   "description": "Target domain name (e.g. anthropic.com, openai.com) for DNS, TLS certificate, and security header OSINT"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/preflight-agentdiet-dev-domain-osint-tls-certificate-security-headers-1474ee47/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)