polymarket_dart

A Dart SDK for the Polymarket CLOB API — REST, WebSocket, EIP-712 signing, HMAC auth, on-chain approvals, and order management.

Features

52 CLOB API methods — markets, orderbook, pricing, order management, rewards, auth
GammaClient — 6 methods for market/event discovery, tags, and search (no auth required)
DataClient — 5 methods for user positions, trades, activity, and holders
EIP-712 signing — order signing for both EOA and GnosisSafe wallets
HMAC Level 2 auth — API key management and authenticated requests
On-chain approvals — EOA (direct Polygon RPC) and GnosisSafe (gasless relayer)
WebSocket — live orderbook, trades, RTDS price feeds
Pure Dart — no Flutter dependency, works in any Dart environment

Installation

Add to your pubspec.yaml:

dependencies:
  polymarket_dart: ^0.3.1

Then run:

dart pub get

Quick Start

import 'package:polymarket_dart/polymarket_dart.dart';

void main() async {
  // CLOB public API — no auth needed
  final client = ClobClient();
  final markets = await client.getMarkets();
  print(markets.data.first.question);
  client.close();

  // Market discovery via Gamma API — no auth needed
  final gamma = GammaClient();
  final topMarkets = await gamma.getMarkets(
    active: true,
    order: 'volume24hr',
    ascending: false,
    limit: 5,
  );
  print(topMarkets.first.question);
  gamma.close();
}

Usage

See docs/plan/GUIDES.md for detailed examples covering public market data, GammaClient discovery, DataClient analytics, EIP-712 API key creation, placing orders (EOA and GnosisSafe), on-chain approvals, and WebSocket subscriptions.

Prerequisites

EOA Trading

A Polygon wallet private key with MATIC for gas
USDC on Polygon for collateral

Run on-chain approvals once before trading:

final wallet = PrivateKeyWalletAdapter('0x...');
await ensureEoaApprovals(wallet, onStatus: print);

GnosisSafe Trading

A GnosisSafe address funded with USDC
Builder Program API credentials from polymarket.com/settings?tab=builder

Run gasless approvals once:

final relayer = RelayerClient(
  wallet: wallet,
  creds: BuilderCredentials(
    apiKey: '...',
    secret: '...',
    passphrase: '...',
  ),
);
await relayer.runApprovals(safeAddress);

Contract Addresses (Polygon)

Contract	Address
USDC (USDC.e)	`0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174`
CTF	`0x4D97DCd97eC945f40cF65F87097ACe5EA0476045`
CTF Exchange	`0x4bFb41d5B3570DeFd03C39a9A4D8dE6Bd8B8982E`
Neg Risk Exchange	`0xC5d563A36AE78145C45a50134d48A1215220f80a`
Neg Risk Adapter	`0xd91E80cF2E7be2e162c6513ceD06f1dD0dA35296`

Testing

# Unit tests (no network)
dart test test/hmac_auth_test.dart test/eip712_test.dart

# CLOB public API
dart test test/clob_client_test.dart --tags integration

# Gamma API (market discovery)
dart test test/gamma_client_test.dart --tags gamma

# Data API (user analytics)
dart test test/data_client_test.dart --tags data

# L2 auth (requires PRIVATE_KEY in .env)
dart test test/auth_test.dart --tags auth

# Approvals (requires PRIVATE_KEY in .env)
dart test test/approvals_test.dart --tags approvals

# GnosisSafe relayer (requires BUILDER_* creds in .env)
dart test test/relayer_test.dart --tags relayer

# Full suite (91 tests)
dart test --tags integration

Create a .env file in the project root:

PRIVATE_KEY=0x...
FUNDER_ADDRESS=0x...          # GnosisSafe address
BUILDER_API_KEY=...
BUILDER_API_SECRET=...
BUILDER_API_PASSPHRASE=...

Dependencies

http — HTTP client
web_socket_channel — WebSocket
pointycastle — secp256k1 ECDSA, Keccak-256
crypto — HMAC-SHA256
convert — hex encoding

License

MIT