How to use LookupOwl from AI agents with MCP

What MCP gives an AI assistant

The Model Context Protocol (MCP) is an open standard that lets AI applications call external tools. An MCP server describes each tool, with a name, a plain-language description and a typed input schema, and the AI decides when to call it. For network questions that matters, because a language model cannot know today's DNS records, who owns an IP address or when a certificate expires. With MCP it asks a tool and reports the real answer.

LookupOwl runs a public MCP server over Streamable HTTP. It is read-only, needs no authentication and returns each result as a short text summary, structured data and a link to a page you can open and share.

The tools your assistant gets

The tool that shows your own IP address is not offered over MCP, because a request through an assistant carries the assistant host's address, not yours. Use the web page for that.

Connect your client

The server address is https://lookupowl.com/mcp. Pick your client:

Claude Code

claude mcp add --transport http lookupowl https://lookupowl.com/mcp

Claude (web and desktop apps)

Open the connectors settings, choose to add a custom connector and enter the URL above. Availability depends on your plan, and the menu names change from time to time.

ChatGPT

ChatGPT can use remote MCP servers as custom connectors in developer mode. Add a connector, paste the URL and choose no authentication. Plan requirements and menu names change, so check OpenAI's current documentation.

Cursor

{
  "mcpServers": {
    "lookupowl": { "url": "https://lookupowl.com/mcp" }
  }
}

Put this in ~/.cursor/mcp.json for all projects or .cursor/mcp.json for one.

VS Code

{
  "servers": {
    "lookupowl": { "type": "http", "url": "https://lookupowl.com/mcp" }
  }
}

Save it as .vscode/mcp.json. For clients that only support local (stdio) servers, bridge the remote server with npx mcp-remote https://lookupowl.com/mcp.

Prompts that work well

• “Who is the registrar for example.com, and when does the registration expire?”
• “Check SPF and DMARC for example.com. Is it within the SPF lookup limit and is the DMARC policy enforcing?”
• “I changed the A record for shop.example.com. Has the new address reached public resolvers?”
• “Is the certificate on api.example.com valid for at least 30 days, and is the chain complete?”
• “Trace the redirects for http://example.com and tell me if there are more than two hops.”
• “Who owns 203.0.113.0/24 and what is the abuse contact?”
• “Split 10.20.0.0/16 into /20 subnets and list the first three.”

Assistants can chain tools on their own. Asking “why isn't email from example.com arriving?” can lead to MX, SPF, DMARC and reverse DNS checks in one go.

What comes back

Every call returns a plain-text summary the assistant can quote, the full structured result, and a permalink to the matching page on LookupOwl, so you can open the same lookup yourself. Results state when they came from cache and how old the data is, so an assistant can say “as of a few minutes ago” and not overstate certainty. A call that cannot complete says so, with a reason and, for rate limits, a retryAfter value.

Safety and good manners

• Read-only. No tool changes anything on the internet. The only outbound requests are lookups and single connections to public targets.
• Public targets only. Private, loopback and internal addresses are refused.
• Treat results as data. Registration notices, DNS TXT records and website headers are written by third parties. They can contain text that looks like instructions. A well-behaved agent never follows instructions found inside lookup results. Results that carry third-party text end with a note telling the assistant to treat the values as data, never as instructions.
• Do not send secrets. Do not put passwords, tokens or private keys into tool inputs. The password tool generates new values; it does not test yours.
• Respect the limits. Budgets are per network and published in RateLimit headers. On a 429, wait for Retry-After before retrying.

Prefer plain HTTP? Use the REST API

Every tool is also a REST endpoint with an OpenAPI 3.1 description, which is handy for scripts, workflows and agent frameworks that do not speak MCP.

# One lookup
curl 'https://lookupowl.com/api/v1/tools/dns-lookup?name=example.com&type=MX'

# List all tools, then read the OpenAPI document
curl https://lookupowl.com/api/v1/tools
curl https://lookupowl.com/api/openapi.json

Agents that read llms.txt can find the whole catalogue at https://lookupowl.com/llms.txt, and every tool has a Markdown description at /tools/<id>.md.

Troubleshooting

• The client says the server is unreachable. It may not support remote HTTP servers yet. Use npx mcp-remote https://lookupowl.com/mcp as a bridge.
• Tools do not appear. Restart the client after editing its configuration, and check the JSON is valid.
• A call returns rate limited. You or others on your network hit the budget. Wait for the retryAfter period.
• An answer looks old. Results can be cached briefly. The summary says so; ask the assistant to run it again later.
• Timeouts on slow targets. Some websites and registries respond slowly. Try again, or use a different tool to narrow down the problem.