How to build a marketplace with AI

These are the parts a marketplace needs before it is useful. Each one is something the plan covers.

• Seller onboarding and KYC: Turn a user into a payable seller with verified identity, without Forge storing identity documents.
• Listings and media: Sellers create structured listings with photos, pricing, category attributes and a draft/review/published lifecycle.
• Search, filters and discovery: Find the right listing fast: keyword, category, price, location, rating, availability, sort.
• Orders and the escrow state machine: A single, auditable order lifecycle from payment to release, with deadlines.
• Payments, platform fee and payouts: Collect from the buyer, take the platform fee, pay the seller, and be able to explain every cent.
• Buyer-seller messaging: Let parties talk about a listing or order while keeping the transaction on-platform.
• Reviews and reputation: Build trust with verified-purchase reviews and a seller reputation score.
• Disputes, refunds and resolution: Resolve problems fairly without a manual spreadsheet and without losing money to chargebacks.
• Trust and safety: Keep the marketplace free of fraud, prohibited items and off-platform leakage.

• Seller dashboard and analytics: Sellers manage listings, orders, earnings and payout status.
• Notifications: Tell the right party when something needs action.

Each table below becomes part of the Postgres database that belongs to your app.

• categories: small, cached in memory and at the edge; commission_bps lets the take rate vary per category.
• listings: status: draft|pending_review|published|paused|removed; rank_key is a precomputed integer (recency + rating + conversion) refreshed by cron so sort is an index scan; search column maintained by trigger.
• listing_media: max media per listing and bytes per seller are capped; status uploaded|processed|rejected.
• orders: status: pending_payment|paid_held|in_progress|delivered|completed|released|cancelled|refunded|disputed; amounts are integer minor units; amount = platform_fee + seller_net is a CHECK constraint; price is snapshotted from the listing at order time.
• order_events: append-only audit of every state transition; the order row and its event are written in one transaction.
• ledger_entries: double-entry-lite: each posting group has balanced debit and credit rows; accounts like buyer_funds, escrow_held, seller_payable, platform_fee, refunds; append-only, corrected only by reversing entries.
• payouts: status: pending|held_for_review|paid|failed|reversed; the unique order_id is the double-payout guard.
• reviews: only creatable when the order is completed; rating 1-5 CHECK; status published|flagged|removed.
• conversations: unread counters updated in the same transaction as the message insert.

• No custom KYC or identity-document storage.
• No learned ranking, ML fraud scoring or multi-currency presentment in phase 1.
• No off-platform payment flows: messaging masks contact details until payment.
• Multi-currency and tax handling: plan for it, build it later.
• Learned ranking and fraud models: plan for it, build it later.

Forge64 matches your description to one of 12 reference architectures, writes the plan and data model into the project, generates the app, and runs a quality gate over the code before you see it. Each app gets its own Postgres database and sign-in with no per-user fee. Hosting on Forge Cloud and Forge Payments are rolling out.

This is a reference design for the category, not a promise that every item is generated today. Built-ins such as email, background jobs, file uploads and search are coming soon, so anything here that needs them is something you add yourself for now.

What does a marketplace need first?

Seller onboarding and kyc, listings and media, search, filters and discovery, orders and the escrow state machine, payments, platform fee and payouts and buyer-seller messaging. The plan for a marketplace covers all of these before it generates code.

What should I leave out of the first version of a marketplace?

No custom KYC or identity-document storage. No learned ranking, ML fraud scoring or multi-currency presentment in phase 1. No off-platform payment flows: messaging masks contact details until payment.

Which products define the marketplace category?

Well-known examples include Etsy, Airbnb, Fiverr, Upwork and Thumbtack. Use them to decide which features your users expect, then describe your own version.

• Marketplace architecture
• Example prompt for a marketplace
• Marketplace security checklist
• Marketplace scaling checklist
• Often combined: SaaS dashboard
• Often combined: online store
• All app types