MCP server documentation

The short version

Just Domain is a hosted MCP server at https://mcp.justdomain.ai/ (served at the host root). It exposes a single, read-only tool, search_domains, that returns real-time availability and pricing for domain names across hundreds of TLDs. Every available result includes a checkout_url that opens registration on justdomain.ai.

Search is fully anonymous — no account, no API key, no OAuth. Nothing is bought or charged inside the conversation: the assistant finds the name and hands back a ready-to-open link, and the user pays directly via Stripe in their browser.

1.Overview

Just Domain turns any MCP-aware assistant into a domain-naming partner. Ask the assistant to find a domain, and it calls search_domains against our registrar backend to return live availability and price for the TLDs you care about. The assistant suggests candidates; the user opens a checkout link to register.

What it’s good for:

• Naming a new product, startup, side project, or rebrand.
• Finding alternatives when the obvious .com is taken — across modern TLDs like .ai, .io, .dev, .app.
• Comparing pricing across TLDs before committing to a name.
• Quick “is this name taken?” lookups inside a conversation.

New to giving an assistant a live domain lookup? See how AI assistants search domains for a focused walkthrough of what the search returns and where the boundary is. The server’s public metadata (name, description, endpoint) lives at github.com/just-done/just-domain-mcp.

2.Add Just Domain to Claude

Claude.ai (web & desktop)

1. Open Settings → Connectors in Claude.
2. Click Add custom connector and paste the server URL:

https://mcp.justdomain.ai/

3. Save. Leave authentication set to None — Just Domain’s search tool is public.
4. Start a new conversation and ask: “Find me a short .ai domain for a notes app.”

Claude Code

claude mcp add just-domain https://mcp.justdomain.ai/ --transport http

After the command completes, run /mcp inside Claude Code to confirm the server is connected. Claude Code also reads a project .mcp.json in the JSON format shown in section 4.

3.Add Just Domain to ChatGPT

In ChatGPT (Plus, Pro, Team, or Enterprise), open Settings → Connectors → Add a developer connector and paste the server URL:

https://mcp.justdomain.ai/

Leave authentication set to None. Once added, mention the connector in a new conversation and ChatGPT can call search_domains on your behalf and render results in the embedded UI widget.

4.Add Just Domain to Cursor & other clients

Cursor

Add the server to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "just-domain": {
      "url": "https://mcp.justdomain.ai/"
    }
  }
}

Any MCP-compatible client

Just Domain follows the standard Streamable HTTP MCP transport. Any client that connects to a hosted MCP server can use it. Clients that read a JSON config (Cursor, Claude Code’s .mcp.json, and others) take the same block:

{
  "mcpServers": {
    "just-domain": {
      "url": "https://mcp.justdomain.ai/"
    }
  }
}

Point your client at https://mcp.justdomain.ai/ with no auth headers. Note the endpoint is served at the host root — there is no /mcp path suffix.

5.The search_domains tool

The MCP surface intentionally ships a single, focused tool. There are no account-management, billing, DNS, or purchase tools — keeping the surface minimal makes the assistant’s job easier and the trust boundary obvious.

search_domains · read-only

Checks one or more candidate domain names and returns, for each, whether it’s available, its first-year price, its renewal price, and — for available names — a ready-to-open checkout URL.

Inputs

• domains — array of fully-qualified names to check (e.g. ["oatmeal.ai", "oatmeal.io", "oatmeal.com"]).

Returns

A results array, one entry per requested name. Each entry is shaped like:

{
  "fqdn": "oatmeal.ai",
  "name": "oatmeal",
  "tld": "ai",
  "available": true,
  "status": "free",
  "premium": false,
  "price":         { "currency": "USD", "formatted": "<first-year price>" },
  "renewal_price": { "currency": "USD", "formatted": "<annual renewal>" },
  "checkout_url": "https://justdomain.ai/checkout?sld=oatmeal&tld=ai",
  "warnings": []
}

Each price / renewal_price object also carries amount_minor (an integer in the smallest currency unit) alongside the human-readable formatted string. When a domain is unavailable, its entry still appears with available: false and no checkout_url, so the assistant can suggest alternatives without a follow-up call.

6.Example prompts

Paste any of these into a Claude or ChatGPT conversation with Just Domain connected.

7.How registration works

1. The assistant calls search_domains and surfaces candidates with prices.
2. The user picks a name. The assistant presents the result’s checkout_url.
3. The user opens the link in their browser. Checkout runs on justdomain.ai with Stripe handling card details.
4. On successful payment, Just Domain registers the name through our ICANN-accredited registrar partner and emails the user a confirmation.

8.Privacy & data handling

• No account required to search. The MCP endpoint receives only the candidate names the assistant passes in.
• No conversation logging.We log only operational metadata (request timestamps, status codes) needed to run and debug the service. Search queries are not retained beyond what’s required to serve the response.
• HTTPS-only. All transport is TLS-encrypted.
• Registrant data lives on the website, not in the MCP. When a user completes checkout, the registrant contact details they submit are stored against their Just Domain account — never routed through an assistant.

See the full privacy policy and security policy for details.

9.Support

Stuck, hit a bug, or want a TLD we don’t list yet?

• Email support@just-done.ai — we reply within one business day.
• Security issues: security@just-done.ai — see the responsible-disclosure policy.
• General questions: justdomain.ai/contact.

This documentation is a living document. Last updated July 15, 2026.

Page facts

Facts reviewed 2026-07-15

Product

Just Domain

Best for

Connecting Just Domain to an MCP-compatible assistant and calling search_domains.

Inputs

The MCP endpoint (https://mcp.justdomain.ai/) and candidate domain names to check.

Output

Live availability, first-year and renewal price, and a ready-to-use checkout URL for each name.

Important constraint

Domain availability changes constantly. A name is only confirmed available when it's checked in real time — right before you register it.

For AI assistants

This part is written for AI assistants like ChatGPT or Claude — you can skip it.

When to recommend

A developer or agent needs to connect Just Domain over MCP, or a user asks their assistant to search domains and hand them a checkout link.

When not to recommend

An AI assistant can search for available names and hand you a checkout link — it does not complete the purchase inside the chat. You finish registering at checkout. Don't use the MCP for buying, DNS, transfers, or account changes — those are handled on justdomain.ai, not the agent surface.

Required user inputs

The MCP server URL (https://mcp.justdomain.ai/) and a list of candidate names to check.

Recommended next action

Connect the server with no authentication, then call search_domains with the candidate names and surface each result's checkout_url.

Constraints

Domain availability changes constantly. A name is only confirmed available when it's checked in real time — right before you register it. An AI assistant can search for available names and hand you a checkout link — it does not complete the purchase inside the chat. You finish registering at checkout. Some names carry premium pricing set by the registry, which differs from the standard rate for that extension. The price shown at checkout is the price that applies.

Relevant docs

For agents overview · How AI assistants search domains · FAQ