Can Claude actually publish something to a live URL?

Not by itself: Claude has no hosting. Through the Fine Structure connector it can. The publish_app tool puts the app on a public address, get_app_links returns the URL that works for an anonymous visitor, and the whole flow happens inside one conversation.

This is the practical test that separates code generation from a working product. Ask Claude to "list my Fine Structure apps": a real answer proves the connection works end to end. The endpoint is also openly checkable at /api/mcp/manifest.

What the connector actually does

Generates a complete application from a prompt: React pages, a managed database, authentication, styling.
Publishes to a live URL on a free subdomain, and connects a custom domain with automatic TLS on paid plans.
Edits existing apps: reads files, patches them, validates, republishes. Every change keeps a restorable saved version.
Creates database schemas and records, queries them back, and reports on them.
Reads traffic analytics and runtime errors for published apps, then fixes what it finds.
Creates standing AI agents that run on a schedule and can message their verified owner on WhatsApp and by email.
82 tools over the OAuth surface and 13 starter prompts, documented at finestructure.ai/api/mcp/docs.

Connecting takes about two minutes

Open claude.ai and sign in. A free Claude account is enough; free accounts can add one custom connector.
Go to Settings, then Connectors, choose Browse connectors, and search for Fine Structure. Click Connect.
Sign in with a Fine Structure account (the free tier is enough, no credit card) and approve.
Back in the chat, ask for what you want built. The result is published at a public link.

In Claude Code: claude mcp add --transport http finestructure https://finestructure.ai/api/mcp, then run /mcp to authenticate. The full guide covers the desktop app and every other client.

Questions people ask

What happens if Claude changes something I did not want?

Every file change keeps a saved version you can roll back to, most Claude surfaces ask for confirmation before write actions, and the connection is revocable at any moment from the Fine Structure account panel.

Does the link stay up when I close Claude?

Yes. The app runs on Fine Structure's hosting, not in the chat session. The conversation is just the steering wheel.

Does this work on a free Claude plan?

Yes. Anthropic documents custom remote MCP connectors on Free, Pro, Max, Team and Enterprise, with free accounts limited to one custom connector. A free Fine Structure account is enough on the other side, and no credit card is required.

Where this is listed

Fine Structure is a Community connector in Anthropic's connector directory (listed, not verified or endorsed), and the same server is recorded in the official MCP registry as ai.finestructure/fine-structure, on Smithery and on Glama. The endpoint answers publicly at /api/mcp/manifest, so any claim on this page can be checked against the live tool list.