Opencals

Booking infrastructure for service businesses.
REST API · TypeScript SDK · Open-source templates · AI agent skills · Shopify app

     

Opencals is a booking and service-commerce platform that ships as two things at once:

• A managed SaaS — staff dashboard, customer-facing booking storefront, Shopify integration, Stripe payments, and multi-location scheduling for service businesses (salons, fitness studios, clinics, rental shops).
• Headless booking infrastructure — a public Storefront REST API, a typed TypeScript SDK, open-source Next.js templates, and AI agent skills that let developers (and their AI coding tools) build fully custom booking experiences on top of the same engine.

Base URL: https://api.opencals.com · Auth: Authorization: Bearer sfk_…

npm install @opencals/storefront-sdk

import { setupOpencals, ProductService } from "@opencals/storefront-sdk";

// Call once at app startup — configures the global client
setupOpencals({ apiKey: "sfk_your_api_key" });

// List bookable services
const { data: products } = await ProductService.list({ query: { take: 50 } });

// Get real-time availability for a service
const { data: slots } = await ProductService.getCurrentAvailabilities({
  path: { productId: products.items[0].id },
  query: { date: "2026-10-01" },
});
// → [{ start, end, staffMemberId }]

Full docs, more endpoints, and the interactive playground → opencals.com/docs

Every Opencals developer account comes with free development stores — no credit card, no trial timer. Create one, seed it with a realistic dataset, point a template at it, and you have a live booking site with real data.

1. Create a store → app.opencals.com/register

2. Seed it with a working business — pick a dataset and your store fills with services, staff members, locations, customers, appointments, and orders:

3. Clone a template and deploy

npx create-next-app -e https://github.com/letsopencals/template-haar my-booking-site

Add your store's API key, deploy to Vercel, done.

Development stores stay free for as long as you need them. When you're ready for real bookings, switch to production. → opencals.com/open-source

All templates are MIT-licensed. Clone, add your API key, deploy.

Products & collections    Staff members & locations    Real-time availability
Cart management           Checkout (Stripe + deposits)  Payment confirmation
Customer self-service     Reschedule / cancel           Orders & invoices
Add-ons & custom duration Discounts & credit balances   Webhooks

All endpoints are documented with request/response examples in 3 languages (TypeScript, cURL, Python) and an interactive playground — no API key needed to browse. → opencals.com/docs

• Agencies — Clone a template, add the client's API key, rebrand. One codebase, many clients. MIT license, no royalties.
• Developers building service apps — Use the REST API or TypeScript SDK to embed booking into any existing web or mobile product.
• AI-assisted development — Install the agent skills in Claude Code, Cursor, or Codex and let your AI build the integration with ground-truth API knowledge.
• Shopify merchants — Install the Opencals Shopify app for native appointment booking as Shopify orders, or combine the Shopify app with a custom headless frontend via the Storefront API.
• Service businesses — Use the hosted dashboard at app.opencals.com and the standalone storefront — no developers needed.

• 🌐 Website — opencals.com
• 🛠️ Open source & dev stores — opencals.com/open-source
• 📖 Developer docs — opencals.com/docs
• 📦 Shopify App Store — apps.shopify.com/opencals
• 💼 LinkedIn — linkedin.com/company/opencals
• 🚀 Product Hunt — producthunt.com/products/opencals-service-commerce-platform
• 📬 Contact — opencals.com/contact