Documentation

Demystify Tools is a library of privacy-first utilities. Most run entirely in your browser — no uploads, no signup, no tracking — and keep working offline. You can reach the same tools three ways, all private by design.

Three ways to use a tool

  1. In your browser. The default. Open a tool and use it — nothing leaves your device.
  2. Over the REST API. POST /api/v1/{tool} with JSON. 21 tools bound today.
  3. Through MCP. Run the local server so your AI assistant can call the tools deterministically.

Guides

API documentation

Call any bound tool over a simple REST endpoint. OpenAPI 3.1, anonymous free tier, RFC-9457 errors.

MCP documentation

Give your AI assistant deterministic tools over the Model Context Protocol — the engine computes, the model never guesses.

Embed a tool

Drop any tool into your own site with one <script> tag. Sandboxed iframe, auto-sizing, zero tracking.

Trust & privacy

Every privacy claim mapped to the control that enforces it — and how it's verified.

Quality & coverage

What's live, generated from the registry. Every calculator ships hand-computed goldens.

Contribute on GitHub

Standards, engine + zod I/O, goldens, and the propagation checklist. PRs and tool requests welcome.

Install the packages

The engines, registry, design tokens and self-host runner are versioned packages (publishing is pending — see the repo). The MCP server runs locally:

# once published
npx demystify-tools-mcp