Polymarket Mini

A local Polymarket-style prediction market app with:

• Next.js trading UI
• Express CLOB server
• EIP-712 signed orders
• Local order books, open orders, cancellations, and fills
• Foundry contracts for a full Anvil setup

Quick Start

npm run setup
npm run dev

Then open:

• UI: http://localhost:3001
• CLOB API: http://localhost:3000

The app starts in preview/dry-run mode when no clob-server/.env exists. You can browse the Polymarket-like UI immediately. Chain-backed market creation and signed order settlement require the full local chain setup below.

Useful Commands

npm run dev        # run CLOB + UI together
npm run dev:clob   # run only the CLOB server
npm run dev:ui     # run only the Next.js UI on port 3001
npm run build      # build the UI
npm run check      # build UI and syntax-check server files

Full Local Chain Setup

Start Anvil:

anvil

Deploy contracts from another terminal:

PRIVATE_KEY=<anvil-account-private-key> \
OPERATOR_ADDRESS=<operator-wallet-address> \
forge script script/Deploy.s.sol:Deploy --rpc-url http://localhost:8545 --broadcast

Copy the env template:

cp clob-server/.env.example clob-server/.env

Update clob-server/.env with the deployed USDC_ADDRESS, CTF_ADDRESS, EXCHANGE_ADDRESS, ORACLE_ADDRESS, and set OPERATOR_KEY to the operator private key.

Run everything:

npm run dev

Notes

• Quick-start mode intentionally uses OPERATOR_KEY=dry-run; it is for fast UI review.
• Never commit real private keys or production secrets.
• The UI expects the CLOB API at http://localhost:3000.