Toolalize MCP

An MCP server for Toolalize — 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:

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.

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)

npx toolalize-mcp

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

{
  "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 — 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

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).

toolalize mcp