Dns

What dns does

The dns MCP server provides read-only checks for DNS, email authentication, and related domain security controls. Its 81 tools cover areas including SPF, DMARC, DKIM, DNSSEC, SSL/TLS, MTA-STS, MX, NS, CAA, BIMI, TLS-RPT, DANE, HTTP security headers, reverse DNS, DNS hygiene, subdomain takeover, and DNSKEY strength.

A domain scan combines many checks into a parallel audit and assigns findings to scoring categories. Results can include a Stage 0–4 maturity classification, from Unprotected to Hardened. The scoring system caps stages according to the observed score rather than allowing a high label from limited evidence.

The server also supports trust-surface analysis, supply-chain mapping, attack-path simulation, compliance mapping for NIST 800-177, PCI DSS 4.0, SOC 2, and CIS Controls, and provider-aware remediation artifacts. Checks do not change target systems or require authorization from the scanned domain.

How it works

The hosted endpoint uses Streamable HTTP with JSON-RPC 2.0 at https://dns-mcp.blackveilsecurity.com/mcp. Clients can also use the native stdio CLI from the blackveil-dns npm package or the legacy HTTP+SSE transport. Streamable HTTP clients must retain the Mcp-Session-Id returned during initialization and send it with later requests. They must also send the negotiated MCP-Protocol-Version.

Most checks use public Cloudflare DNS-over-HTTPS lookups. Authoritative infrastructure checks query authoritative and root nameservers directly over TCP port 53. For authenticated callers, the authoritative infrastructure check can test whether nameservers refuse zone transfers, without retrieving zone data.

The recommended starter tools are scan_domain, explain_finding, and compare_baseline. Tool metadata also identifies functional groups, scoring tiers, and whether a check runs inside scan_domain.

Setup and configuration

Hosted use requires no installation and no API key. Add the Streamable HTTP endpoint to an MCP client, or verify availability with GET https://dns-mcp.blackveilsecurity.com/health. Claude Desktop users can install the provided .mcpb extension. Claude Code can add the server with its HTTP transport, and Smithery provides an installation command for the repository.

For local stdio use, install or otherwise run the blackveil-dns-mcp CLI supplied by the blackveil-dns npm package. The material does not specify required environment variables for running the server.

Tools and capabilities

The dns MCP server includes tools for:

• Running single-domain, batch, comparative, and baseline scans.
• Checking email authentication, DNS records, TLS, resolver consistency, DNS hygiene, and infrastructure configuration.
• Finding lookalike, shadow, sibling, and subdomain assets.
• Assessing spoofability, shared SaaS senders, MX reputation, fast flux, RBL status, and other threat signals.
• Generating fix plans and publishable SPF, DMARC, DKIM, MTA-STS, and rollout artifacts, then validating applied changes.
• Mapping third-party supply-chain dependencies, attack paths, and compliance controls.
• Starting asynchronous brand-discovery jobs and retrieving their status and findings.

Some additional reconnaissance, threat-feed, cloud-bucket, OSINT, and Microsoft Entra capabilities depend on operator deployments or bindings. They may be unavailable or degrade to an unprovisioned state in self-hosted deployments without those bindings.

Limitations and notes

The service is primarily a passive DNS and security assessment tool. It does not authorize changes on scanned domains, and its checks are read-only. Certain operations are asynchronous, including some brand-discovery, bucket-discovery, and OSINT workflows, so clients must start a job, poll its status, and fetch the resulting findings or report.

The hosted endpoint uses session handling: unsupported protocol versions return HTTP 400, while expired or terminated sessions return HTTP 404 and require a new initialization. The project is source-available under BUSL-1.1.