# Domain OSINT, TLS Certificate & Security Headers Recon

> Domain OSINT, TLS Certificate & Security Headers Recon is a paid API for AI agents from prompt-guard.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://prompt-guard.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: prompt-guard.agentdiet.dev
- Website: https://prompt-guard.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/prompt-guard-agentdiet-dev-domain-osint-tls-certificate-security-7461fc75
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2G_nvFyjYhVSrm2oLqFyJ

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 prompt-guard-agentdiet-dev-domain-osint-tls-certificate-security-7461fc75
```

Example prompt: Can you run a full domain OSINT scan on stripe.com — I want to see the live DNS resolution (IPv4 and IPv6), who issued the TLS certificate and when it expires, and the HTTP security header grade?

## When to prefer this

Choose this endpoint when you need a combined, single-call view of a domain's DNS resolution, TLS certificate health, and HTTP security posture — particularly useful for security audits, vendor assessments, incident triage, or automated compliance checks where you want live data rather than cached or passive records.

## Known failure modes

- Domain does not exist or fails DNS resolution — empty or error response for DNS fields
- Domain has no TLS certificate (HTTP-only) — TLS fields will be null or absent
- Domain is unreachable or times out — partial or error response
- Invalid domain format provided — validation error returned
- Rate limiting or payment failure ($0.01 per call via x402) — 402 Payment Required response

## 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://prompt-guard.agentdiet.dev/v1/subdomain-scan)

## Output

Returns live DNS resolution results (IPv4 and IPv6 addresses), TLS certificate metadata (issuer, expiry date, validity status), and an HTTP security header audit including presence/absence of headers like HSTS, CSP, X-Frame-Options, and an overall security grade.

## 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/prompt-guard-agentdiet-dev-domain-osint-tls-certificate-security-7461fc75/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from prompt-guard.agentdiet.dev](https://www.zero.xyz/host/prompt-guard.agentdiet.dev/llms.txt)