Website builder MCP server for Claude Code, Codex and ChatGPT

This is the MCP server for iter0, an AI website builder for founders. Add it to Claude Code, Codex or ChatGPT and your agent can build a website from a short brief, edit a saved page and publish it to a free name.iter0.app address, all from the chat you already use. The server runs at iter0.com, so you connect to one address instead of hosting anything yourself.

Through MCP, the agent can:

• build a launch website from a brief or from a reference site you are allowed to use;

• make one focused edit to a saved page;

• read your saved designs and their status;

• check a site for problems before you share it;

• publish a site to a free name.iter0.app address, and take it offline again;

• put a finished site on an iter0 canvas, then read and reply to the comments left there.

Paid steps show a price quote first. Nothing is spent until you confirm the quote.

• Endpoint: https://iter0.com/api/mcp (Streamable HTTP)

• Setup page: https://iter0.com/mcp

• Developer docs: https://iter0.com/developers

• OpenAPI: https://iter0.com/openapi.json

• Agent summary: https://iter0.com/llms.txt

This repository holds connection instructions, a registry file and an agent skill. The server runs at iter0.com, and its source code is not published here.

Connect

Claude Code:

claude mcp add --transport http iter0 https://iter0.com/api/mcp

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "iter0": {
      "url": "https://iter0.com/api/mcp"
    }
  }
}

Codex (~/.codex/config.toml):

[mcp_servers.iter0]
url = "https://iter0.com/api/mcp"

ChatGPT: add iter0 as a connector with the endpoint above, then sign in to your iter0 account when ChatGPT asks. The setup page has the current steps.

If your client needs a different format, use its own steps for adding a Streamable HTTP server, and give it the endpoint above.

Related MCP server: croquis-mcp

Sign in

Two tools work without signing in: iter0_health and iter0_get_developer_docs.

The other tools use your iter0 account through OAuth 2, with the scopes sites:read, sites:build and sites:edit. Your client opens a sign-in page the first time it needs one. The server publishes its protected-resource metadata at https://iter0.com/.well-known/oauth-protected-resource.

For direct API calls (not MCP), create a bearer token in your account settings: https://iter0.com/settings/api-keys. The API reference is at https://iter0.com/developers.

Tools

23 tools are listed by the server. Costs are from the tool descriptions.

No sign-in

Building (paid steps quote first)

Designs

Publishing and checks (free)

Canvas (free)

To push a build from your computer, install the local server (commands at https://iter0.com/mcp). Its iter0_push_site takes rootDir, the build folder, and reads the pages from there, inlining their relative CSS, scripts and images. Read feedback with iter0_get_canvas_feedback, then call iter0_get_canvas_snapshot with the designId and pageKey before editing to see notes on that page. Set view to canvas for an overview. Check warnings and feedbackTruncated for missing renders or omitted items. The skill sets out the full canvas loop: push, open the canvasUrl, read feedback, take a snapshot, reply, then push again with each page's expectedVersion. See skills/iter0-website-builder/SKILL.md.

Credits

• A build costs 1 credit. An AI edit costs 0.5 credit. Publishing, checks, canvas tools, undo and restore are free.

• Every paid step returns an exact quote first, and a quote expires after 15 minutes. Nothing is spent until you confirm the quote, in the iter0 card or by saying yes in chat.

• The free plan includes 3 credits a month. Current plans are at https://iter0.com/pricing.

Agent skill

skills/iter0-website-builder/SKILL.md tells a coding agent which tools to use, in what order, and when to stop and ask you.

Official MCP Registry

server.json describes the remote server for the official MCP Registry, under the name io.github.inchwormz/iter0-mcp. That name was registered before this repository was renamed from iter0-mcp, and it stays the same.

Limits

• Use real customer facts and references you are allowed to use.

• A build that has started is not a finished site. Check the result of each run.

• Generated pages do not guarantee rankings, traffic or conversion.

Licence

The files in this repository are under the MIT licence. iter0 itself is a hosted service governed by its terms and privacy policy.