# 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 (IPv4/IPv6), TLS certificate inspection (issuer/expiry), and HTTP security header grading for a given domain.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/subdomain-scan?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-8c026212
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9E1w8cEwMEZov7dHbq3-a

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-8c026212
```

Example prompt: Can you run a full DNS and TLS security recon on anthropic.com — I want to see the IPv4/IPv6 addresses it resolves to, who issued the SSL certificate and when it expires, and how its HTTP security headers are graded?

## When to prefer this

Choose this endpoint when you need a quick, live OSINT snapshot of a domain's DNS posture, TLS certificate health, and HTTP security header configuration in a single call. It is ideal for pre-launch audits, competitive intelligence, incident response triage, or verifying that a domain is properly secured before integrating with it.

## Known failure modes

- Domain does not exist or is unresolvable — returns DNS resolution failure
- Domain has no HTTPS — TLS certificate fields may be empty or null
- Firewall or rate-limiting on the target domain blocks header inspection
- Invalid or malformed domain input — returns validation error
- Timeout if the target server is slow or unresponsive

## 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/subdomain-scan)

## Output

Returns live DNS resolution results (IPv4 and IPv6 addresses), TLS certificate metadata including issuer and expiry date, and an HTTP security header grade/score for the target domain.

## 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-8c026212/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)