Is the SecurityTrails API free to use?

SecurityTrails offers a Free Tier API plan which allows 50 API requests per month. This is excellent for specific, targeted OSINT investigations. For automated or large-scale recon, you would need a commercial subscription.

What is historical DNS good for?

Companies often migrate infrastructure and hide behind WAFs like Cloudflare. Historical DNS reveals the original origin IP addresses used before the WAF was implemented, which might still be active and vulnerable to direct attacks. It's a critical tool in penetration testing.

How can I find related domains for a target company?

Use the `get_associated_domains` tool. It uses proprietary correlation to find other domains owned by the same entity. You can also use `get_domains_by_ip` to find what else is hosted on their IP space.

SecurityTrails MCP Connector for Claude

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Uncover IT infrastructure — access DNS history, subdomains, reverse IP lookups, WHOIS data and advanced domain intelligence for ultimate OSINT.

10 tools Official Updated Jun 28, 2026 Official Vinkius Partner

More Details Connect to Claude

Connect your SecurityTrails account to any AI agent and empower your OSINT, bug bounty, and threat intelligence workflows with the world's most comprehensive domain and IP database.

What you can do

Attack Surface Mapping — Instantly enumerate all subdomains for any target organization to map their external footprint
Historical DNS Analysis — Look back in time at DNS records (A, MX, NS, TXT) to find hidden infrastructure, bypassed firewalls, or legacy systems
Reverse IP Lookups — Find all domains hosted on a specific IP address to identify shared hosting or related corporate assets
Advanced Threat Hunting — Use the SecurityTrails DSL (Domain Specific Language) to query the entire internet for specific tech stacks or vulnerable infrastructure
Ownership Intelligence — Access current and historical WHOIS records to track domain ownership changes and unmask hidden threat actors
Corporate Associations — Discover domains strongly associated with your primary target to expand your investigation scope

How it works

Subscribe to this server
Sign up at SecurityTrails to get your API key (Free tier available)
Run intelligence queries directly from Claude, Cursor, or any MCP-compatible client

Who is this for?

Security Researchers & Pentesters — accelerate recon and asset discovery during engagements
Bug Bounty Hunters — find forgotten subdomains and out-of-scope assets associated with target companies
Threat Intelligence Analysts — correlate IPs, domains and WHOIS records to track APT infrastructure
Brand Protection Teams — identify typosquatting and malicious domains targeting your organization
System Administrators — audit their own external attack surface and verify DNS propagation