Headless Commerce Engine

Part of the worlds-biggest-software-project initiative.

An API-first commerce platform with AI personalisation built into the core, not bolted on as third-party plugins.

The Headless Commerce Engine is an open-source, MACH-aligned commerce backend for engineering teams building custom storefronts, B2B portals, conversational commerce, and multi-channel retail experiences. It targets the gap between expensive enterprise platforms (commercetools, Elastic Path) and the smaller open-source ecosystem (Medusa, Saleor, Vendure) by making AI-native capabilities a first-class part of the API surface.

Why Headless Commerce Engine?

Enterprise MACH platforms like commercetools and Elastic Path require dedicated engineering teams and contracts that frequently exceed $100k/year, putting composable commerce out of reach for mid-market brands.
SaaS platforms such as Shopify lock the backend into a single ecosystem with multi-region limitations and constrained tax and pricing logic, even when used in headless mode via the Storefront API.
Pure-API offerings like Commerce Layer ship without an admin UI or bundled storefront framework, forcing teams to build or buy multiple additional tools before going live.
Existing open-source options (Medusa, Saleor, Vendure) treat AI as an integration point rather than a built-in capability, so recommendations, search ranking, and personalisation typically require third-party services.
Composable commerce is forecast to grow from USD 6.44B in 2024 to USD 31.50B by 2034, but no leading open-source project currently combines MACH architecture with native AI features.

Key Features

Catalog and Inventory APIs

Product, variant, and SKU management via GraphQL and REST APIs
Real-time inventory tracking and reservation
Multi-channel catalog support (web, mobile, marketplace)
Multi-region and multi-market catalog structures
Schema introspection for type-safe client code generation

Cart, Checkout, and Orders

Shopping cart API with item, quantity, and modifier management
Checkout flow API with payment gateway integration (Stripe, PayPal)
Order creation, retrieval, and lifecycle management
Fulfillment and shipment management
Webhook events for orders, payments, and inventory changes

Pricing, Promotions, and B2B

Multiple price lists per market and customer segment
Promotion and discount rules engine
B2B features including pricebooks, quotes, and company accounts
Multi-vendor and wholesale capabilities
PCI DSS compliant checkout via tokenisation patterns

Customer Accounts and Authentication

Customer account and order history APIs
OAuth 2.0 and OpenID Connect for API authentication
Staff portal and admin dashboard for operational tasks
Plugin and extensibility architecture for custom logic

AI-Native Capabilities

Vector search and LLM-ranked product recommendations
Conversational commerce API for natural-language catalog queries and checkout
Dynamic bundle and pricing generation based on context, inventory, and demand
Automated catalog enrichment from supplier data sheets
ML-based fraud detection and risk-based checkout friction

AI-Native Advantage

Incumbents treat AI features as add-on integrations: search plugins, recommendation services, and external fraud tooling glued together over webhooks. The Headless Commerce Engine embeds vector search, LLM-ranked results, conversational queries, automated attribute extraction, and anomaly detection directly into the commerce APIs. This means a single GraphQL or REST call can return personalised, ranked results or initiate a natural-language checkout, without integrating separate vendors per channel.

Tech Stack & Deployment

The project aligns with the MACH Alliance reference architecture: microservices, API-first, cloud-native, headless. Expected deployment modes include self-hosted (full control over data and infrastructure) and managed cloud, mirroring the patterns used by Medusa, Saleor, and Vendure. APIs are published with OpenAPI 3.0 specifications and a GraphQL schema, secured via OAuth 2.0 / OpenID Connect, and wired between services using CloudEvents (CNCF) for vendor-neutral event integration.

Market Context

The global headless commerce market was valued at approximately USD 1.74 billion in 2025 and is projected to reach USD 7.16 billion by 2032 at a 22.4% CAGR (Swell, 2025). Gartner forecasts that 60% of organisations will rely on composable commerce architectures by 2027. Incumbent pricing ranges from $80/month (Shopify) to $500k+/year for commercetools enterprise contracts, with Commerce Layer and Elastic Path typically starting at $30k–$100k/year. Primary buyers are CTOs, VPs of Engineering, Digital Commerce Directors, and Platform Architects at mid-to-large retailers with multi-region, multi-brand, or B2B requirements.

Project Status

This project is in the research and specification phase.
Contributions, feedback, and domain expertise are welcome.

Contributing

We welcome contributions from developers, domain experts, and potential users. See CONTRIBUTING.md for guidelines.

Important: All contributions must be your own original work or clearly attributed open-source material with a compatible licence. Copyright infringement and licence violations will not be tolerated and will result in immediate removal of the offending contribution. If you are unsure whether a piece of code, text, or other material is safe to contribute, open an issue and ask before submitting.

Licence

Licence to be determined. See discussion for context.