# 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 any given domain

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/cert-transparency?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-04eafee7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UBRBwG4ZKPdXPIoU5jX0A

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-04eafee7
```

Example prompt: Can you check the TLS certificate details, DNS resolution, and HTTP security headers for openai.com — I want to know who issued the cert, when it expires, and how the security headers are graded?

## When to prefer this

Choose this endpoint when you need a single-call OSINT sweep of a domain's DNS, TLS, and HTTP security posture without setting up infrastructure. Ideal for security reconnaissance, pre-acquisition due diligence, phishing domain investigation, or vendor security validation. Prefer this over manual lookups or separate DNS/SSL tools when you need combined certificate, DNS, and security header data in one response at low cost ($0.01/call).

## Known failure modes

- Domain does not exist or fails DNS resolution — no records returned
- Domain is unreachable or times out during live probing — connection error
- Domain has no TLS certificate (HTTP only) — TLS fields absent or null
- Invalid domain input (e.g. empty string, malformed) — validation error
- Temporary upstream resolution failure — retry may resolve

## 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/cert-transparency)

## Output

Returns live DNS resolution data (IPv4/IPv6 addresses), TLS certificate metadata (issuer, validity dates, expiry status), and an HTTP security grade reflecting the presence or absence of security headers such as HSTS, CSP, X-Frame-Options, and similar directives for the queried 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-04eafee7/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)