MVP Development for Trading Platform - Circulate

Developer Needed – Lean MVP Build for Marketplace Startup (Circulate)
Project Overview
I’m building a startup called Circulate.
Circulate is a local marketplace platform where users trade goods and services using an internal credit wallet system instead of cash.
Think:
Facebook Marketplace + OfferUp + a credit-based barter marketplace
The goal is a lean but functional MVP to prove the concept to users and investors—not a bloated enterprise build.
I want to use existing integrations/services wherever practical to keep development time and costs low.
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Core Concept
Users trade using internal platform credits instead of cash.
Rules:
• every user starts at 0 credits
• users can spend down to a controlled negative balance (example: –100 credits)
• users earn credits by selling goods/services
• purchases are blocked if the user would exceed the negative threshold
• every completed transaction incurs a 6% platform transaction fee
• that fee goes into the platform’s internal reserve wallet
Example:
User buys an item for 25 credits:
• buyer balance = –25
• seller receives 23.5 credits
• platform reserve receives 1.5 credits (6%)
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What I Need Built
Core Product
A responsive web application (mobile-friendly) where users can:
• create accounts
• verify email/phone
• browse marketplace listings
• post items/services
• search/filter listings
• message buyers/sellers
• complete transactions
• rate users
• manage their internal wallet
• view transaction history
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Security / Fraud Prevention
Required:
• email verification AND phone/SMS verification
• duplicate account prevention
• suspicious activity monitoring
• fraud flags
• admin fraud review tools
• account suspension capability
Goal:
Prevent:
• fake accounts
• duplicate users
• abuse of negative credit spending
• scam behavior
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Internal Wallet / Credit System (Core)
This is a required core feature.
Need:
• internal wallet per user
• visible credit balance
• negative spending limit (can go negative on 1 trade up to -100, can’t trade again til positive, can’t purchase an item for 40 credits, go -40 then purchase again till you get to -100, once you go negative purchasing frozen till go positive)
• purchase eligibility logic
• automatic wallet debits/credits
• admin balance adjustments
• transaction ledger
• reserve wallet tracking
Logic:
• user starts at 0
• can spend down to –100
• cannot exceed spending threshold
• credits earned through sales
• credits deducted through purchases
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Platform Transaction Fee
Required:
Every completed transaction must automatically collect:
6% platform fee
Example:
25-credit sale:
• seller receives 23.5
• reserve wallet gets 1.5
Need:
• automatic fee calculation
• reserve wallet accounting
• fee tracking/reporting
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Marketplace Features
Users must be able to:
• create listings (QR code for listing to send money to sellers wallet)
• edit listings
• delete listings
• upload photos
• title/description
• select category
• set credit price
• browse listings
• search
• filter
• save/favorite listings
• report listings
Listings should support:
• physical products
• services
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Transaction Flow
Keep simple.
No escrow.
Flow:
1. in-app messaging
2. users arrange exchange
3. buyer transfers credits via QR code, 6% fee collected
4. “item sold” upon transfer of credits
5. wallet balances update
6. buyer transfers credits via QR code 6% fee collected
7. ratings prompted
Need:
• completed transactions
• disputes
• admin oversight
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Messaging
Need:
• in-app buyer/seller chat
• listing-linked messaging
• blocking users
• message reporting
Use third-party service if practical.
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Ratings / Trust
Need:
• star ratings
• written reviews
• completed trade count
• trust indicators
• verified badges
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Admin Dashboard
Must include:
• user management
• suspend/freeze users
• fraud review
• listing moderation
• transaction oversight
• dispute management
• wallet adjustments
• reserve wallet monitoring
• analytics dashboard
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Analytics (Lean MVP)
Track:
• users
• active users
• listings
• completed transactions
• credits traded
• reserve wallet growth
• disputes
• fraud incidents
• repeat usage
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Technical Preferences
Open to recommendations.
Prefer existing services where practical.
Likely stack:
Frontend:
• React / Next.js
Backend:
• Node.js / Supabase / Firebase
Database:
• PostgreSQL or equivalent
Hosting:
• Vercel / AWS / cloud
Messaging:
• Stream / Sendbird / Pusher
Analytics:
• PostHog
Admin:
• Retool or custom lightweight admin
Storage:
• AWS S3 / Cloudflare
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Deliverables
Need:
• working MVP
• frontend
• backend
• database
• internal wallet logic
• fee logic
• admin dashboard
• deployment
• source code ownership
• documentation
• bug support after launch
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What I Need From You
Please include:
1. estimated cost
2. estimated timeline
3. recommended stack
4. similar marketplace experience
5. fraud prevention recommendations
6. lean MVP recommendations
7. hosting/monthly costs
8. maintenance estimate
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Important
This is NOT a polished enterprise app.
Goal:
build the leanest secure MVP possible that proves the concept.
Use integrations where practical instead of unnecessary custom development.