---
name: api.x402dataapi.com
description: api.x402dataapi.com provides two DNS and HTTP inspection utilities: one checks a domain's email security configuration (MX, SPF, DMARC) and returns a numeric risk score, and the other checks whether a public URL is accessible to AI agents by inspecting HTTP status, robots.txt, sitemap, and anti-bot challenge signals. Both are single-shot, read-only checks against publicly observable infrastructure.
host: api.x402dataapi.com
---

# api.x402dataapi.com

This host serves agents and developers that need lightweight pre-flight checks before interacting with external domains or URLs. It covers two distinct but complementary concerns: whether a domain is configured to resist email spoofing and phishing, and whether a target URL can be crawled by an AI agent without being blocked. It does not perform active email sending, real-time uptime monitoring, or any checks requiring authentication.

## When to use this host

Use this host when an agent needs to perform pre-flight due diligence on an external domain or URL — specifically to assess email anti-spoofing configuration or to verify AI crawlability before attempting to fetch content. For email security checks (SPF, DMARC, MX scoring), this is the appropriate tool. For agent accessibility checks (robots.txt, llms.txt, challenge detection), use check-agent-accessibility. Do not use this host for real-time email deliverability testing, inbox placement verification, uptime monitoring, or any checks against private or authenticated endpoints. It is not a substitute for a full security audit or a web scraping framework — it only inspects publicly observable DNS and HTTP signals.

## Capabilities

### Domain Security Assessment

Inspects a domain's DNS-level email security records (MX, SPF, DMARC) and produces a numeric score with a list of identified configuration issues, enabling agents to evaluate phishing risk or anti-spoofing posture.

- **`check-mail-security`** — Checks a domain's MX records, SPF, and DMARC configuration and returns a numeric security score with a list of identified issues.

### Agent Accessibility Inspection

Determines whether a public URL is reachable and permissible for AI agent crawling by checking HTTP status, robots.txt rules, sitemap presence, llms.txt discovery, and anti-bot challenge detection.

- **`check-agent-accessibility`** — Checks whether a public URL is accessible to AI agents and browsers by inspecting HTTP status, robots.txt rules, sitemap availability, llms.txt discovery, and challenge detection.

## Workflows

### Domain Trust Pre-Flight

*Use when an agent needs to evaluate the overall trustworthiness and reachability of an unknown domain before interacting with it — covering both its email security posture and whether its web presence is accessible to AI agents.*

1. **`check-mail-security`** — Retrieve the domain's MX, SPF, and DMARC configuration and score to assess phishing and spoofing risk.
2. **`check-agent-accessibility`** — Check whether the domain's primary URL is accessible to AI agents, confirming robots.txt permissions and absence of anti-bot challenges.

## Skill reference

### `check-mail-security`

**Mail Security Check** — Checks a domain's MX records, SPF, and DMARC configuration and returns a numeric security score with a list of identified issues.

*Use when:* Use when an agent needs to assess a domain's email security posture, validate anti-spoofing configuration (SPF/DMARC), evaluate phishing risk, or confirm mail sender-policy setup before trusting or communicating with that domain.

*Not for:* Do not use for real-time email deliverability testing or inbox placement checks; this endpoint inspects DNS-level mail security records only, not actual email sending behavior.

**Inputs:**

- `domain` (string, required) — Public domain name to inspect for MX, SPF, and DMARC records.

**Returns:** Returns domain, parsed MX records, SPF and DMARC objects with raw records and policy fields, an integer security score (0–100), and an array of issues (empty if none).

**Example:** `{"domain":"example.com"}`

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### `check-agent-accessibility`

**Agent Accessibility Check** — Checks whether a public URL is accessible to AI agents and browsers by inspecting HTTP status, robots.txt rules, sitemap availability, llms.txt discovery, and challenge detection.

*Use when:* Use when an agent needs to determine if a target URL can be crawled or scraped by AI agents before attempting to fetch content, or to verify robots.txt permissions and detect anti-bot challenges.

*Not for:* Do not use for private or authenticated URLs; this endpoint only inspects publicly accessible http/https URLs. Not suitable for real-time uptime monitoring — this is a single-shot accessibility check.

**Inputs:**

- `url` (string, required) — Public http or https URL to inspect for agent accessibility, robots.txt rules, and challenge detection.

**Returns:** Returns accessible_by_basic_agent boolean, curl and browser HTTP status codes, robots.txt found/allows flags, challenge_detected boolean, challenge_type, and a notes array.

**Example:** `{"url": "https://example.com"}`

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