# Onto MCP server

> Converts web URLs into clean Markdown and provides AI-readability scoring to help AI agents consume web content efficiently.

- Repository: https://github.com/ravixalgorithm/onto-mcp
- Page: https://hostedmcp.org/servers/ravixalgorithm/onto-mcp
- Transport: stdio, remote
- Stars: 1
- License: MIT
- Latest version: 1.5.2

## Install

### Claude Code

```sh
claude mcp add --env 'ONTO_API_KEY=<YOUR_ONTO_API_KEY>' onto-mcp -- npx -y @ontosdk/mcp
```

### Cursor (`~/.cursor/mcp.json`)

```json
{
  "mcpServers": {
    "onto-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@ontosdk/mcp"
      ],
      "env": {
        "ONTO_API_KEY": "<YOUR_ONTO_API_KEY>"
      }
    }
  }
}
```

### VS Code (`.vscode/mcp.json`)

```json
{
  "servers": {
    "onto-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@ontosdk/mcp"
      ],
      "env": {
        "ONTO_API_KEY": "<YOUR_ONTO_API_KEY>"
      }
    }
  }
}
```

### VS Code CLI

```sh
code --add-mcp '{"name":"onto-mcp","type":"stdio","command":"npx","args":["-y","@ontosdk/mcp"],"env":{"ONTO_API_KEY":"<YOUR_ONTO_API_KEY>"}}'
```

### Claude Desktop (`claude_desktop_config.json`)

```json
{
  "mcpServers": {
    "onto-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@ontosdk/mcp"
      ],
      "env": {
        "ONTO_API_KEY": "<YOUR_ONTO_API_KEY>"
      }
    }
  }
}
```

### Codex

```sh
codex mcp add onto-mcp --env 'ONTO_API_KEY=<YOUR_ONTO_API_KEY>' -- npx -y @ontosdk/mcp
```

### Codex config.toml (`~/.codex/config.toml`)

```toml
[mcp_servers.onto-mcp]
command = "npx"
args = ["-y", "@ontosdk/mcp"]

[mcp_servers.onto-mcp.env]
ONTO_API_KEY = "<YOUR_ONTO_API_KEY>"
```

### Gemini CLI

```sh
gemini mcp add -s user -e 'ONTO_API_KEY=<YOUR_ONTO_API_KEY>' onto-mcp npx -- -y @ontosdk/mcp
```

### Gemini settings.json (`~/.gemini/settings.json`)

```json
{
  "mcpServers": {
    "onto-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@ontosdk/mcp"
      ],
      "env": {
        "ONTO_API_KEY": "<YOUR_ONTO_API_KEY>"
      }
    }
  }
}
```

## Environment variables

| Name | Required | Secret | Description |
|---|---|---|---|
| `ONTO_API_KEY` | yes | yes | Your Onto API key (get one at https://app.buildonto.dev/read/keys — free tier includes 1,000 credits/month). |
| `ONTO_API_BASE` | no | no | Optional override for the Onto API base URL. Defaults to https://api.buildonto.dev. |

## Tools (6)

- `url`
- `fresh`
- `urls`
- `site`
- `mode`
- `limit`

## FAQ

### How much does it cost to use Onto?

There is a free tier providing 1,000 credits per month with no credit card required. Paid tiers range from $9 for 10,000 credits to custom enterprise pricing.

### Can I process multiple URLs at once?

Yes, the batch tool allows you to read, score, or extract data from an explicit list of up to 50 URLs or an entire site via its sitemap in a single call.

### What happens if a URL fails during a batch process?

If a URL in a batch request fails, the credits for that specific URL are refunded.

### How does Onto ensure content is clean for AI?

Onto uses a rule-based engine to strip away HTML noise like React components, returning agent-ready Markdown that is typically much smaller than raw HTML.