Two-Sided Marketplace Builder

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

A configurable, AI-native marketplace platform that lets founders and product teams launch two-sided transaction platforms with built-in payments, trust scoring, and intelligent matching -- without enterprise pricing or vendor lock-in.

Two-Sided Marketplace Builder is an open-source platform for creating and operating two-sided marketplaces -- connecting buyers with sellers, renters with owners, or service providers with clients. It targets startup founders launching niche verticals, enterprise product teams adding marketplace channels, and agencies building white-label platforms for clients. The core problem it solves: existing tools force a choice between fast-but-limited SaaS (Sharetribe at $119/mo with constrained logic) and powerful-but-inaccessible enterprise platforms (Mirakl at six-figure contracts with months-long implementation).

Why Two-Sided Marketplace Builder?

The mid-market gap is real. Sharetribe gets you to launch fast but limits custom business logic and lacks B2B capabilities. Mirakl handles enterprise scale but requires a certified system integrator and enterprise-tier budgets. Nothing serves the mid-market operator who needs both flexibility and speed.
B2B marketplace tooling is underdeveloped. B2B marketplaces are projected at USD 36 trillion globally by 2026, yet purpose-built B2B tooling is limited to Yo!Kart (dated UI, high integration effort) and Mirakl (enterprise-only). Purchase orders, credit terms, and organisation accounts remain niche add-ons rather than first-class features.
Vertical-specific workflows are missing. Current platforms are built for generic product sales. Services marketplaces, rental platforms, and professional services exchanges all need specialised transaction workflows (escrow, multi-step approval, availability calendars) that require extensive custom development today.
No-code and self-hosted options both have ceilings. Bubble offers flexibility but hits performance walls at scale. CS-Cart gives source code ownership but demands ongoing DevOps overhead and has weak C2C support. Neither provides AI-native capabilities out of the box.
Seller onboarding is still manual. Across all incumbents, vendor verification and category classification require human review queues -- a bottleneck that scales linearly with marketplace growth.

Key Features

Seller and Buyer Management

Separate buyer and seller onboarding flows with profile management
Identity verification integration for seller onboarding (document check or business verification)
Operator admin console with vendor approval, listing moderation, and dispute management
White-label branding with custom domain, logo, and colour scheme

Listing and Catalogue Management

Product or service listings with photos, pricing, availability, and category organisation
Configurable listing types for different marketplace verticals (products, services, rentals)
Operator-controlled category structure with configurable attributes per category
AI listing quality optimiser providing automated suggestions for titles, descriptions, and pricing

Transaction Workflows

Two-sided transaction lifecycle: inquiry or booking, approval, payment, and completion
Stripe Connect split payment with configurable commission rates and scheduled seller payouts
Multi-currency support with automatic conversion for cross-border transactions
Buyer-to-seller messaging before and during transactions

Search and Discovery

Text search, category filtering, and location-based listing search
Embedding-based semantic search surfacing relevant results for natural language queries
Personalised buyer feed with recommendation engine based on purchase history and browse behaviour

Trust and Quality

Buyer and seller rating and review system with moderation controls
AI-driven fraud and trust scoring for transaction risk assessment
Vendor quality scorecard tracking on-time fulfilment, return rates, and satisfaction metrics

AI-Native Advantage

The AI capabilities in this project address specific operational bottlenecks that incumbents solve with manual processes. Automated seller onboarding uses AI to review business documents, verify identity, and classify seller categories -- eliminating the human review queue that becomes a scaling bottleneck. Dynamic trust and fraud scoring assesses transaction risk in real time using behavioural signals, reducing chargebacks and policy abuse. Embedding-based semantic search matches buyer intent to listings rather than relying on keyword filters, and AI-generated listing optimisation helps sellers improve conversion rates based on marketplace-wide performance data.

Tech Stack & Deployment

Payments: Stripe Connect for split payments, commission handling, and seller payouts. Stripe's hosted model offloads PCI DSS scope from the marketplace operator.
Standards: OAuth 2.0 / OpenID Connect for identity federation; ISO 20022 for cross-border payment messaging; PSD2-compatible Open Banking APIs for European payout rails.
Architecture: Headless API-first design enabling fully custom frontends, with a default responsive storefront included.
Deployment: Self-hosted and cloud options. Self-hosted deployments provide full code ownership; managed cloud option reduces DevOps overhead.

Market Context

Global ecommerce platform infrastructure is projected at USD 13.92 billion in 2026, growing to USD 61.83 billion by 2034 at a CAGR of approximately 20.5% (Fortune Business Insights, 2026). The broader digital marketplace market was valued at USD 580 billion in 2024 and is forecast to exceed USD 1 trillion by 2030 (NextMSC, 2025). SaaS marketplace tools range from USD 30-120/month for indie founders up to enterprise contracts exceeding USD 100k/year, with revenue-share models of 1-2% of GMV common at the managed-service end. Primary buyers are startup founders launching niche verticals, enterprise product teams adding marketplace channels, and agencies building white-label marketplaces.

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.