# domain_check_v1

Measures how resilient a public web domain is from the outside and returns a weighted score out of 100, a per-category breakdown, and prioritised findings explaining what to fix first. Use it to audit a domain you do not control, to verify a fix after deployment, or to compare several domains on the same scale. Covers TLS certificate validity and protocol version, HTTP to HTTPS redirection, HSTS, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, cache directives, response time, DNS redundancy, IPv6 availability, CDN detection and software version disclosure. Everything is read from the public internet: nothing is authenticated, no ports are scanned, and no credentials are needed. Do not use it for private, internal, or localhost hostnames, for IP addresses, or to test a service you need logged-in access to. For a free score without the detailed findings, use domain_check_score_v1 instead. Price: $0.01 per call (x402, USDC on Base). No signup, no API key.

Agent View of the PolicyLayer registry record for `domain_check_v1`. HTML page: https://policylayer.com/tools/com-feranor-resilience/domain-check-v1

## Facts

- Tool: `domain_check_v1`
- Server: Feranor Resilience (`https://www.feranor.com/mcp`) — https://policylayer.com/tools/com-feranor-resilience.md
- Homepage: https://github.com/https://www.feranor.com/mcp
- Risk category: Read (Low risk)
- Registry record: grade C, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 1 (1 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `domain` | string | yes | Bare domain name, apex or subdomain, for example 'example.com' or 'www.example.com'. Scheme, path, port and query string are ignored if present. IP addresses an |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "domain_check_v1",
    "arguments": {
      "domain": "<domain>"
    }
  }
}
```

## Why domain_check_v1 is rated Low

domain_check_v1 performs passive external assessment of a domain's security posture via public DNS/HTTP/TLS queries. It retrieves and analyzes publicly available information with no side effects on the target domain or any system. The tool cannot modify, execute code on, delete from, or charge money to any system.

From the tool's own definition: "Tool measures and returns a weighted score, per-category breakdown, and findings. Verbs in description are 'Measures', 'returns', 'audit', 'verify', 'compare' — all read-only operations. No mutation, deletion, execution, or financial operations are performed."

Risk signals: Bulk/mass operation — affects multiple targets

## Use case

AI agents call domain_check_v1 to retrieve information from Feranor Resilience without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Feranor Resilience:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "domain_check_v1": {}
  }
}
```

## Other tools on Feranor Resilience (2)

- `domain_check_batch_v1` — Read — https://policylayer.com/tools/com-feranor-resilience/domain-check-batch-v1.md
- `domain_check_score_v1` — Read — https://policylayer.com/tools/com-feranor-resilience/domain-check-score-v1.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-feranor-resilience · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-feranor-resilience