calculo — The infrastructure for calculations

Build, embed, and scale calculators with one API.

calculo is an open-source platform for calculations. It provides a complete infrastructure layer — from a full-featured calculator engine and graphing engine to REST APIs, embeddable widgets, SDKs, and a visual builder.

Just as Stripe became the default platform for payments, calculo aims to be the default platform developers use whenever they need calculations, calculators, mathematical engines, graphing, formulas, or interactive widgets.

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Features

• Calculator Engine — Arithmetic, scientific, trig, hyperbolic, logarithms, complex numbers, matrices, vectors, statistics, probability, financial, and 60+ built-in functions.
• Graphing Engine — 2D cartesian, parametric, and polar graphing with smooth rendering.
• REST API — Evaluate expressions, render graphs, and manage calculators programmatically.
• TypeScript SDK — First-class TypeScript support with full type safety.
• Embeddable Widgets — Drop calculators anywhere with a single line of HTML.
• 8 Themes — Dark, light, OLED, high-contrast, glass, neumorphism, minimal, corporate — switchable at runtime.
• JSON Configuration — Every calculator is configurable with a simple JSON object.
• Draggable & Resizable — Drag calculators around, resize from the corner.
• React Components — Use @calculo/react for deep framework integration.
• Monorepo — pnpm workspaces, Turborepo, strict TypeScript.

Quick start

npm install @calculo/sdk

import { Calculo } from '@calculo/sdk';

const calculo = new Calculo('cal_your_api_key');

const { result } = await calculo.evaluate({
  expression: 'sin(pi/4)^2 + cos(pi/4)^2',
});

console.log(result); // 1

Embed in HTML

<script src="https://calculo-fawn.vercel.app/embed.js"></script>
<div
  data-calculator="calc_123"
  data-theme="dark"
  data-width="100%"
  data-height="650">
</div>

React component

import { Calculator } from '@calculo/react';

export function Demo() {
  return (
    <Calculator type="scientific" theme={{ mode: 'dark' }} graph={true} />
  );
}

REST API

curl https://api.calculo.dev/v1/evaluate \
  -H "Authorization: Bearer cal_..." \
  -H "Content-Type: application/json" \
  -d '{"expression": "sin(pi/2) + 2^8"}'

API

Method	Path	Description
POST	/v1/evaluate	Evaluate a mathematical expression
POST	/v1/render	Generate graph data from expressions
POST	/v1/calculators	Create a calculator configuration
GET	/v1/calculators/:id	Get a calculator
PATCH	/v1/calculators/:id	Update a calculator
DELETE	/v1/calculators/:id	Delete a calculator
POST	/v1/embed	Generate embed code
GET	/v1/templates	List marketplace templates
GET	/v1/usage	Get usage statistics
POST	/v1/api-keys	Create an API key

Monorepo structure

calculo/
├── apps/
│   ├── web/          # React 19 + Vite + TanStack Router
│   └── api/          # Hono + Drizzle + Supabase
├── packages/
│   ├── calculator-engine/  # Expression evaluation engine
│   ├── graph-engine/       # 2D graphing engine
│   ├── parser/             # Tokenizer + recursive descent parser
│   ├── sdk/                # TypeScript client SDK
│   ├── embed/              # Embeddable widget
│   ├── ui/                 # Shared React components
│   ├── config/             # Themes, button layouts
│   └── shared/             # Types, constants, validators, errors
├── turbo.json
├── pnpm-workspace.yaml
└── package.json

Stack

• Frontend: React 19, Vite, TanStack Router, TanStack Query, Tailwind CSS
• Backend: Hono, Drizzle ORM, Zod
• Infrastructure: Vercel, Supabase PostgreSQL, Supabase Auth
• Package manager: pnpm workspaces
• Tooling: Turborepo, TypeScript (strict), ESLint, Prettier

Development

# Install dependencies
pnpm install

# Start development servers (web + api)
pnpm dev

# Build all packages
pnpm build

# Type check all packages
pnpm typecheck

License

MIT

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