Commerce Layer | Sell everywhere

# Commerce Layer > Commerce Layer is an API-first, headless commerce platform that provides > the infrastructure for globally distributed, multi-market ecommerce. It > enables AI agents, developers, and brands to sell everywhere — online, > in-store, via mobile apps, shoppable links, IoT devices, and autonomous > AI agent commerce. ## Product - [Universal Checkout](https://commercelayer.io/universal-checkout): API-first, stateless checkout to sell on any channel. Supports multiple markets and currencies, any payment gateway or tax calculator. - [Distributed OMS](https://commercelayer.io/distributed-oms): Manage inventory across multiple stock locations with real-time unified visibility, automatic reservation, and intelligent order splitting. - [Promotion Engine](https://commercelayer.io/promotion-engine): Market-specific promotion rules via a visual editor or JSON-based Rules Engine DSL. Supports tiered discounts, bundle promotions, employee pricing, and custom conditions on any order attribute. - [POS System](https://commercelayer.io/pos-system): In-store commerce engine integrated with online channels, sharing customer profiles across touchpoints. ## Core Concepts - [Headless Commerce](https://commercelayer.io/headless-commerce): What headless commerce is, how Jamstack implements it, why content and commerce should stay decoupled, and how Commerce Layer supports headless architectures natively. - [Composable Commerce](https://commercelayer.io/composable-commerce): How composable commerce lets teams assemble best-of-breed tools — CMS, OMS, CRM, PIM, payments — into a tailored stack via APIs. - [Omnichannel Commerce](https://commercelayer.io/omnichannel-commerce): Single-channel vs. omnichannel selling, and how a unified backend powers consistent experiences across web, mobile, in-store, and AI agents. - [Selling Internationally](https://commercelayer.io/selling-internationally): Markets, localization, currency, and re