Predikt

Self-custodial football games on USD₮.

Predict live World Cup ties, run knockout cups, and play fantasy — all under one wallet whose keys never leave your device.

Built on WDK (Tether's self-custodial wallet SDK) for the Tether Developers Cup.

Live → prediktt.xyz

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What it is

An all-in-one football economy. Four ways to play, one self-custodial USD₮ wallet under all of them:

• Predict — call the score on live ties, pool up with mates by invite code, split the pot at full time.
• Organize — run a knockout cup with a real entry fee; the pot auto-pays the winner.
• Fantasy — draft a salary-cap XI from real World Cup squads and climb mini-leagues for a prize pool.
• Free or real — play in points, or stake real on-chain USD₮ any time.

Nobody holds the pot. Buy-ins go into an on-chain escrow contract; payouts settle on-chain straight to your wallet with a real tx hash. The server never custodies funds — the contract does.

Why WDK

Every wallet, USD₮ balance, approve, and escrow deposit/payout runs on @tetherto/wdk-wallet-evm. The 12-word recovery phrase is generated on your device and is your login — the same phrase recovers your whole account (points, pools, squads, cups) on any device, and the server never sees your private key.

Your keys, your money. That's the entire product.

Try it

• Hosted: prediktt.xyz — the full product on a bundled demo chain. No install: grab a wallet, create a pool, join a cup, all live against real World Cup 2026 fixtures.
• Local: run it on your machine (below).

Run it locally

Prerequisites

• Node ≥ 20
• Foundry (for the local anvil chain): curl -L https://foundry.paradigm.xyz | bash && foundryup
• A Postgres to point at (DATABASE_URL), or use the bundled default.

npm run setup     # install deps + compile contracts
npm run demo      # boots anvil + API + web, all local → http://localhost:5173

Deploy

Two-service split (see DEPLOY.md for the full walkthrough):

• Backend → Railway: the Fastify API + a bundled anvil demo chain, single container (Dockerfile). Data lives in a Railway Postgres.
• Frontend → Vercel: the built SPA (root dir web/), pointed at the backend with VITE_API_BASE. Custom domain on prediktt.xyz.

The SPA calls the API cross-origin (fetch + SSE); the server allows it (CORS), so no proxy is needed.

Live data

Fixtures, results, form, crests and live in-play scores are real — FIFA World Cup 2026, two providers behind one code path:

• football-data.org — set FOOTBALL_DATA_API_KEY for true in-play status + scores.
• TheSportsDB — keyless fallback, zero setup.

The server polls every 15s and pushes each change to the browser over one SSE connection (/api/stream), so a goal lands in the UI in about a second. If the feed is unreachable at boot it falls back to a bundled dataset and keeps retrying.

Modes

• local (default) — a local anvil chain + a MockUSDT we deploy, so a judge needs zero real funds and zero keys. Fully offline and deterministic.
• testnet — set GAFFER_MODE=testnet, GAFFER_RPC_URL, GAFFER_OPERATOR_KEY, GAFFER_USDT_ADDRESS to point WDK at a real testnet + real USD₮0. Same code paths.

Architecture

web/  (Vite + React + Tailwind)  ──HTTP / SSE──▶  server/  (Fastify + Node)
  hosted on Vercel → prediktt.xyz                   ├─ wdk/      → @tetherto/wdk-wallet-evm  (self-custodial wallets)  ← WDK
                                                    ├─ chain/    → viem (operator/oracle + reads)
                                                    ├─ store/    → accounts, pools, fantasy, cups  (Drizzle + Postgres)
                                                    └─ football/ → live WC 2026 feed (SSE push)
  hosted on Railway + Railway Postgres
contracts/  (Foundry)  PredictionPool.sol (on-chain escrow) + MockUSDT.sol

Repo structure

Path	What
server/src/wdk/	Self-custodial wallets (@tetherto/wdk-wallet-evm) + escrow treasury
server/src/chain/	viem operator/oracle: deploy, fund, settle, reads
server/src/store/	Accounts, points, pools, fantasy, cups (Drizzle ORM → Postgres)
server/src/football/	Live WC 2026 feed + SSE push
contracts/src/	PredictionPool.sol, MockUSDT.sol
web/src/	React UI (Tailwind v4 design system, motion animations)

Notes

• Predikt is a fan/entertainment sweepstake demo, not a licensed gambling product.
• The default demo uses a local chain + MockUSDT so it's reproducible; the same code targets testnet.
• The repo also contains an optional on-device AI pundit (QVAC, @qvac/sdk) that runs locally via npm run demo. It runs natively on your machine, not in the cloud, so it isn't part of the hosted product.

License

MIT — Predikt Contributors, 2026.