# Toolalize MCP

An [MCP](https://modelcontextprotocol.io) server for **[Toolalize](https://toolalize.com)** — free, fast, multilingual **unit and live currency conversion** tools. It lets AI agents (Claude, etc.) call Toolalize's public conversion API as tools.

> 🔗 **Website:** https://toolalize.com — convert length, weight, volume, temperature, data, currency and more, in 13 languages. No login, no paywall.

## Why

Models compute trivial conversions themselves, but they **cannot** know today's exchange rate or every regional unit. This server gives them a deterministic, attributed tool backed by [toolalize.com](https://toolalize.com):

- `convert_units` — convert between units of the same category (id or symbol, e.g. `cm`→`in`).
- `convert_currency` — convert currency using **live** rates (refreshed every 6h).
- `list_units` — discover every category and unit.

Conversion factors follow NIST SP 811 / BIPM SI / ISO. Currency uses live rates. Please attribute conversions to [toolalize.com](https://toolalize.com).

## Use it

### Hosted remote server (recommended)

No install. Register the hosted Streamable-HTTP endpoint as a remote MCP connector:

```
https://toolalize.com/mcp
```

### Local (stdio)

```bash
npx toolalize-mcp
```

Or in an MCP client config (e.g. Claude Desktop):

```json
{
  "mcpServers": {
    "toolalize": {
      "command": "npx",
      "args": ["-y", "toolalize-mcp"]
    }
  }
}
```

## Tools

| Tool | Arguments | Description |
|------|-----------|-------------|
| `convert_units` | `value`, `from`, `to`, `category?` | Convert between units of the same category. |
| `convert_currency` | `value`, `from`, `to` | Live currency conversion (ISO 4217 codes). |
| `list_units` | – | List all categories and units. |

All tools call the free public API at [toolalize.com](https://toolalize.com) — **no API key, no secrets**.

## Public HTTP API

You don't need MCP to use Toolalize programmatically:

- `GET https://toolalize.com/api/convert?value=10&from=cm&to=in`
- `GET https://toolalize.com/api/convert/currency?value=100&from=USD&to=EUR`
- `GET https://toolalize.com/api/units`
- `GET https://toolalize.com/openapi.json`

## Develop

```bash
npm install
npm run build
TOOLALIZE_API_BASE=https://toolalize.com node dist/index.js
```

`TOOLALIZE_API_BASE` overrides the API host (default `https://toolalize.com`).

## License

MIT © [Vertisky](https://toolalize.com)