4ai – premium .ai domains

npx add-mcp 'https://4ai.ai/mcp'

4ai for AI agents & developers

Let AI assistants and apps find premium.ai domains for your users. 4ai offers an MCP server, open JSON data, an OpenAPI description and embeddable widgets. Free, read-only, no API key.

MCP server

Connect any MCP client (streamable HTTP) to:

https://4ai.ai/mcp

Tools:

• suggest_domains: describe a project in plain words ("telehealth app for mental health") and get the best-fitting.ai domains, each with the reason it fits.
• search_domains: filter by word, category, type and length.
• similar_domains: alternatives to any.ai name, for example one that is taken.
• get_domain: details, offer link and comparable sales for one domain.
• compare_domains: 2 to 5 names side by side, with estimated value ranges.
• get_offer_link: a link to the offer form with the amount and a note filled in. Nothing is sent; the buyer checks and sends the offer.
• how_buying_works: steps, Escrow.com payment, fees and transfer time.
• estimate_domain_value: free value estimate for any.ai name.
• list_categories and ai_domain_sales: categories and publicly reported.ai sales.

Every domain result includes an offer link, so the assistant can send the user straight to buying.

In Claude, add it as a custom connector (Settings → Connectors → Add custom connector) with the URL above. Other MCP-capable assistants and agent frameworks accept the same URL.

Listed in the official MCP Registry as ai.4ai/domains.

Open data

• /data/domains.json: all 255 domains for sale, with categories, type, what each is good for and offer links.
• /data/ai-domain-sales.json and CSV: publicly reported.ai sales with sources.
• Registrations and Anguilla.ai revenue (CSV).
• /api/suggest?q=<project> and ?similar=<name.ai>: best-fitting domains for a project, or alternatives to a name (JSON).
• /openapi.json: OpenAPI 3.1 description, usable for GPT actions and tool calling.
• /llms.txt and /llms-full.txt: plain-text summaries for language models.

The data is free to reuse under CC BY 4.0 with a link to 4ai.ai.

Deep links

• Name ideas for a keyword: /ai-domain-name-generator/?q=health
• Comparable sales for a name: /ai-domain-value-estimator/?q=agent.ai
• A domain page with offer form: /domains/<name>-ai/#make-offer
• The same form with an amount and note filled in: /domains/<name>-ai/?offer=5000&note=…#make-offer (minimum $3,000; the buyer sends it)
• Domains for a project description: /ai-domains-for-sale/?q=telehealth app