Patchwork: Multi-Channel Inventory Sync for Independent Makers

The Idea

Patchwork is a real-time inventory sync and unified order hub for independent makers who sell the same physical goods across multiple platforms simultaneously — Etsy, Shopify, Square POS, and live craft markets — with a killer "Market Mode" that lets sellers check off items sold at a live event and instantly sync availability across every connected channel.

The Problem You Solve

A potter lists 4 of the same mug on Etsy and their Shopify store. They sell 3 at a Saturday craft market, forget to update both listings, and wake up Sunday to 5 orders they cannot fulfill — refunds, angry customers, and damaged reviews. This is not a niche edge case. It is the defining operational headache for any maker selling multi-channel, and it happens constantly.

Existing solutions are either enterprise-priced (Linnworks starts at $400+/month, targets e-commerce operations with warehouses), platform-locked (Etsy's tools do not talk to Shopify), or general-purpose POS (Square knows dollar amounts, not Etsy listing quantities). Nobody has built this for the $0–$100K/year independent maker.

Core Features (MVP)

• Channel Sync: Connect Etsy + Shopify; every quantity change on one platform instantly reflects on the other
• Market Mode: One-tap mobile interface to check off items sold at a live event; all connected listings update in real time
• Unified Order Feed: All orders from all channels in a single timeline view
• Oversell Guard: Automatic "sold out" flag across all channels when stock hits zero; configurable hold buffer (e.g., always keep 1 unit as buffer)
• Sync Log: Audit trail showing what changed, when, and which channel triggered it

Phase 2 additions (months 3–6):

• Square POS integration
• Instagram Shopping sync
• Low stock alerts via SMS (Twilio)
• Per-channel sales comparison dashboard
• Batch listing creator (create once, publish to all)

Pricing

• Free: 1 channel connection, manual sync only, up to 25 SKUs
• Maker — $29/month: 3 channel connections, real-time sync, Market Mode, unlimited SKUs
• Studio — $59/month: 5 channel connections, team members (2 seats), Twilio SMS alerts, sync log history, priority support

Annual billing: 2 months free (20% discount).

Tech Stack

• Frontend: Next.js + TypeScript, deployed on Vercel
• Backend/API: Next.js API routes or lightweight Node service
• Database: Supabase (inventory state, sync logs, user accounts)
• Integrations: Etsy Open API v3, Shopify Admin API, Square Connect API
• Auth: Supabase Auth with OAuth flows for each platform
• Payments: Stripe subscriptions
• Notifications: Twilio SMS for Studio tier low-stock alerts
• Queue: Supabase edge functions or a simple BullMQ Redis queue for sync jobs

How to Build MVP

Week 1–2: Etsy OAuth integration + read/write inventory quantities via Etsy Open API v3. Store sync state in Supabase.

Week 3: Shopify OAuth + Admin API inventory sync. Build the bidirectional sync engine: webhook from Etsy triggers Shopify update and vice versa. Handle race conditions and conflict resolution (last-write-wins with a 2-second debounce).

Week 4: Market Mode — mobile-optimized UI showing all current listings with quantity steppers. Submit triggers immediate sync to all connected channels. Works offline-first with optimistic updates.

Week 5: Stripe billing integration, user onboarding flow, sync log UI. Polish and deploy.

Week 6: Closed beta with 10 makers from Etsy seller communities (Reddit r/EtsySellers, Facebook groups, maker Discord servers). Fix the bugs that will absolutely exist.

Total time: 6 weeks of focused evenings and weekends.

How to Get First Customers

Community seeding (free):

• Post in r/EtsySellers, r/crafts, r/Pottery with a genuine "I built this to solve my own problem" post
• Share in Etsy seller Facebook groups (300k+ member groups exist)
• Post in maker/ceramics Discord communities

Craft market ground game:

• Attend 2–3 local craft markets, talk to vendors directly — the oversell story resonates instantly
• Hand out simple cards with QR codes to the landing page

Content hook:

• Write a single blog post or Twitter/X thread titled "I oversold 8 orders at a craft market last month — here's what I built to fix it." Personal story + product launch. This is highly shareable in maker communities.

Partner channel:

• Reach out to Fairgrounds users (if that product launched) — they already know the organizer side, Patchwork is the vendor side

Paid:

• $200/month Google Ads targeting "etsy shopify inventory sync" — high intent, low competition

Revenue Math

Conservative path to $10k/month:

• 200 Maker plans × $29 = $5,800/month
• 75 Studio plans × $59 = $4,425/month
• Total: $10,225/month at 275 paying customers

Market size check:

• Etsy has 9M+ active sellers. Even 0.003% of them = 270 customers. This is achievable.
• Target the 500k–1M sellers who also have Shopify stores (Etsy itself reports this overlap in their seller data)

Growth: Maker community has high word-of-mouth. A maker who uses Patchwork tells other makers at craft markets. Low CAC if the initial community seeding works.

Why This Is Different

No direct competitor at this price point or niche. Linnworks/ChannelAdvisor target operations managers at growing brands. Nobody targets the individual maker with a Etsy + Shopify + craft market setup at $29/month.

Market Mode is the product. Real-time sync at a live craft market — where you cannot pause to update 4 different apps between each sale — is a genuinely novel feature with no equivalent. It solves the exact moment the pain is highest.

Community moat. Makers talk to each other. A tool built by someone who understands the craft market workflow (not just e-commerce abstractly) earns trust and word-of-mouth that generic tools cannot replicate.

Technical execution bar. Building reliable bidirectional inventory sync across multiple platform APIs with conflict resolution and offline support is non-trivial. A solo maker cannot build this; another developer could, but would need to replicate months of API integration work and the community positioning.

Path to Quitting Day Job

• Month 1–2: MVP with Etsy + Shopify sync, Market Mode, 10 beta users
• Month 3: Public launch, first 30 paying customers ($870 MRR)
• Month 5: 100 paying customers (~$3,500 MRR), Square integration shipped
• Month 7: 200 paying customers (~$7,000 MRR), Instagram Shopping sync
• Month 9–10: 275+ customers ($10,000+ MRR), stable enough to consider leaving
• Month 12: 400+ customers ($14,000+ MRR), hire one part-time support contractor

At $10k MRR (roughly $7k–8k after Stripe fees and infrastructure), this is a viable full-time income replacement given a software engineer's risk tolerance and living costs.

Risks & Mitigations

API rate limits and reliability: Etsy and Shopify both have API limits. Mitigation: queue-based sync with exponential backoff; never sync more frequently than needed.

Platform API changes: Etsy has a history of API deprecations. Mitigation: abstract the integration layer so swapping or updating one platform's API does not break others. Monitor developer changelogs.

Platform lock-in concern from Shopify: Shopify may build native Etsy sync (they acquired Handshake). Mitigation: expand to more channels (Square, WooCommerce, Faire) to reduce dependence on any one pairing; the "Market Mode" live event feature is not something Shopify will build.

Small TAM at the niche level: Individual makers are price-sensitive and churn if they stop selling. Mitigation: keep pricing low ($29) so it is a no-brainer recurring expense; build switching costs through sync history, analytics, and team features.

Competition from Zapier/Make automations: Power users build DIY Etsy→Shopify syncs on Zapier. Mitigation: Zapier cannot do real-time sync (polling only, 15-minute delay minimum on free plan); Market Mode is completely impossible to replicate with no-code tools.

Why This Works for You Specifically

You know the maker world firsthand — you sell ceramics, attend craft markets, live the Etsy + live event split-channel problem. You can write the "I built this for myself" launch story authentically because it is true. The technical work (OAuth integrations, webhook-driven sync, real-time UI) is exactly the kind of API integration work senior engineers do fluently. The target customer (individual Etsy/Shopify seller) is reachable through communities you are already adjacent to. And at $29–59/month, you only need a few hundred customers to hit serious income — not thousands.

First Action

Join r/EtsySellers and two Etsy seller Facebook groups today. Spend one week reading posts about inventory problems before writing a single line of code. Collect 5 sellers who will agree to be beta testers. Then build the Etsy OAuth + inventory read/write in a weekend spike to validate the API is actually usable.