Finance and accounting decision
PolyMRR
A capable technical user can build a narrow self-hosted prediction-market for a small community (markets, bets, resolution), but reproducing the product's trust, liquidity, payment/settlement, and polished marketplace features is nontrivial and likely requires more people or time.
Visit website↗Built by Mehdi Ben Haddou, who ships 3 products in this index
Not priced
No pricing page we fetched carried a figure, so there is nothing to compare against. The build side is still real.
$100one-off58 h to build
$50/mo6 h/mo upkeep
No published price to break even against.
Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need - the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship. All PolyMRR alternatives, with the arithmetic →
What a replacement has to do
- User authentication and account management; create and manage prediction markets (questions, outcomes, resolution rules); place bets / record trades and maintain an on-chain/off-chain ledger with atomic transactions; market resolution and payouts with dispute handling; simple realtime UI and live feed of bets; admin panel to promote/feature markets and manage funds.
What it still won’t have
- Verified/trusted dataset (TrustMRR verified data) and its integration
- Built-in liquidity and active user base / live leaderboard
- Polished UX, promotion/ads and marketplace of featured markets
- Any regulatory, payments, and custodial infrastructure handled by vendor
What remains hard
- Product polish and ongoing maintenance
First-year cost
No published price
PolyMRR does not publish a price we could read, so there is nothing to compare against. What building costs is below.
Money you would actually spend
Time you would spend
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What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal self-hosted prediction-market web app using Node.js (Express), Postgres, and React. Core features in scope: email+OAuth auth, create/close markets with multiple outcomes, place bets with account balance checks and transactional ledger, background job to resolve markets and compute payouts, realtime WebSocket feed for bets and market changes, admin UI to mark featured markets. Out of scope: fiat on/off ramps, KYC, payments processor integration, external verified data ingestion. Include error handling, database transactions for bets/payouts, simple unit tests for bet matching and settlement, Dockerfile and deployment instructions for a single VPS.
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 2 cited sources+1
- 3/3 assessment runs agreed+4
- Evidence score62
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time - so the same evidence always produces the same number.
How scoring works →Cited sources · 2
Every page the run actually retrieved.
- official productPolyMRR — Prediction Markets for Indie Startups
- open sourcekuestcom/prediction-market
Integrity checks
What held up, and what did not.
