# Subdomain API MCP server

Find known subdomains of a domain. Passive data; may include historic entries. List or count.

## Links
- Registry page: https://www.getdrio.com/mcp/app-subdomain-subdomains
- Website: https://subdomain.app

## Install
- Endpoint: https://api.subdomain.app/mcp
- Auth: Not captured

## Setup notes
- Remote endpoint: https://api.subdomain.app/mcp

## Tools
- find_subdomains (Find subdomains) - List known subdomains (hostnames) of a root domain. Data is passive (not active scanning): results are historic observations and may include subdomains that no longer resolve or are no longer live. Results are a point-in-time snapshot that changes over time as new subdomains are observed — re-query rather than caching the result. Use for attack-surface mapping, security recon, asset inventory, or SEO host discovery. Hostnames are returned most-recently-seen first. The response always reports `total` (full distinct count known) and a `truncated` flag, so you can tell when more exist beyond `limit`. Endpoint: https://api.subdomain.app/mcp
- count_subdomains (Count subdomains) - Return only the total number of distinct subdomains known for a domain — no list. Cheap and low-token. Use when the user asks "how many subdomains" or you only need the size of the attack surface. Count includes historic subdomains that may no longer be live. It is a point-in-time figure that changes over time, so treat it as current-as-of-query, not a fixed value. Endpoint: https://api.subdomain.app/mcp

## Resources
Not captured

## Prompts
Not captured

## Metadata
- Owner: app.subdomain
- Version: 1.0.1
- Runtime: Streamable Http
- Transports: HTTP
- License: Not captured
- Language: Not captured
- Stars: Not captured
- Updated: Jun 26, 2026
- Source: https://registry.modelcontextprotocol.io