Onto MCP Server: Install & Setup

Install Onto in Claude Code

Remote URL

Claude Code

claude mcp add --transport http onto https://api.buildonto.dev/mcp

mcp.json (Claude Desktop, Cursor, VS Code, Windsurf)

{
  "mcpServers": {
    "onto": {
      "url": "https://api.buildonto.dev/mcp"
    }
  }
}

npm

Claude Code

claude mcp add onto -e ONTO_API_KEY=... -- npx -y @ontosdk/mcp

mcp.json (Claude Desktop, Cursor, VS Code, Windsurf)

{
  "mcpServers": {
    "onto": {
      "command": "npx",
      "args": [
        "-y",
        "@ontosdk/mcp"
      ],
      "env": {
        "ONTO_API_KEY": "..."
      }
    }
  }
}

Replace each ... with your own value.

Frequently asked questions

What does the Onto MCP server do?

Clean Markdown and AI-readability scoring for any URL. Built for AI agents.

Is the Onto MCP server free?

The server is free, but you will likely need an account. The server itself is free, but it connects to a service that needs an account or API key, which may have paid tiers. Check the provider for current pricing.

Does Onto run locally or remotely?

Local + Remote. Can run locally or be used as a hosted remote server.

How do I add Onto to Claude Code?

Run: claude mcp add --transport http onto https://api.buildonto.dev/mcp

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