marketplace-bid-ask-system

name	marketplace-bid-ask-system
description	Use when working on ERTZU products, asks, bids, matching, buy-now, bid acceptance, order creation, market summaries, or marketplace status rules.

Marketplace Bid Ask System

When To Use

Use this skill for product detail pages, marketplace grid behavior, ask creation, bid placement, buy-now checkout, seller bid decisions, order creation, market sales, and any SQL/RPC touching marketplace state.

ERTZU-Specific Instructions

• Preserve the StockX-like model: one perfume product page, many seller asks, many buyer bids.
• Buyers can buy the lowest matching active ask or place bids.
• Sellers can place asks and accept eligible active bids.
• Seller ships to ERTZU first; ERTZU verifies before buyer shipment.
• Match on product_id, fill_level_category, bottle_size_ml, status, price, and expiry.
• Keep lowest ask ordering by lowest price, then oldest creation time.

Files And Areas To Inspect

• src/lib/market.ts
• src/lib/matching.ts
• src/app/listings/page.tsx
• src/app/listings/[id]/page.tsx
• src/app/sell/page.tsx
• src/app/buy/page.tsx
• src/app/bid/checkout/page.tsx
• src/app/notifications/page.tsx
• src/app/checkout/[id]/page.tsx
• supabase/schema-v11-marketplace.sql
• supabase/schema-v12-bid-rules.sql
• supabase/schema-v15-security-hardening.sql
• supabase/schema-v17-bid-decisions-payment.sql
• supabase/schema-v20-community-ranking-votes.sql
• supabase/migrations/*.sql

Concrete Checks

• Verify selectLowestAsk() and SQL buy_now use equivalent fill/size semantics.
• Verify users cannot buy or bid on their own active asks.
• Verify bid floor rules when active asks exist.
• Verify bid at or above lowest ask routes to buy-now behavior.
• Verify place_bid, buy_now, accept_bid, decline_bid, cancel_bid, admin_cancel_ask, and admin_cancel_bid enforce auth and blocked-user rules.
• Verify order rows carry buyer, seller, product, ask, bid, final price, currency, fill level, payment intent, shipping address, and status as needed.
• Verify market sales and notifications are written only after valid matches.
• Verify product_market_summary returns lowest ask, active ask count, highest bid, last sale, and ranking signals used by the UI.

Mistakes To Avoid

• Do not make /listings/[id] an individual seller listing page.
• Do not rely only on client-side userIsAsking checks.
• Do not let client-provided prices decide server-side final price.
• Do not ignore bottle size when multiple sizes exist.
• Do not globally cancel a bid when only one eligible seller declines unless all eligible sellers have declined.
• Do not bypass RPCs with direct table updates for high-risk transitions.