monad-sdk

The official TypeScript SDK for creating and trading prediction markets on Monad.

This SDK provides a high-level abstraction over the on-chain smart contracts (MarketFactory, FeeManager), enabling developers to programmatically create prediction markets, trade outcome tokens (YES/NO), and redeem winnings — all through a clean, typed interface.

Highlights

• One-line market creation — Spin up a fully on-chain prediction market with a single function call. Question, liquidity, deadline — done.
• Built on Monad — Harness 10,000 TPS and sub-second finality. No more waiting around for block confirmations on sluggish L1s.
• Permissionless and composable — Any developer, any agent, any bot can create markets, trade outcomes, and settle positions. No gatekeepers.
• Auto-pilot approvals — The SDK handles ERC20 allowance checks and approvals under the hood. You just say "buy" and it figures out the rest.
• Battle-tested AMM pricing — Built-in CPMM with real-time YES/NO price feeds. Market odds update live with every trade.
• Agent-ready architecture — Designed for AI agents to autonomously create and trade prediction markets. npm install pnp-monad and let your agent loose.
• Type-safe and zero-config — Full TypeScript support with pre-loaded Monad contract addresses. Import, initialize, ship.
• Open source, public npm — Install with npm install pnp-monad. Fully open, fully auditable, no black boxes.

Installation

npm install pnp-monad

Quick Start

1. Initialize the Client

import { PNPClient } from "pnp-monad";

const client = new PNPClient({
  // Defaults to the Monad mainnet RPC if omitted
  rpcUrl: process.env.RPC_URL,
  // Required for any write operations (market creation, trading, redemption)
  privateKey: process.env.PRIVATE_KEY,
});

2. Create a Market

import { ethers } from "ethers";

const endTime = Math.floor(Date.now() / 1000) + 86400; // 24 hours from now

const { conditionId, receipt } = await client.market.createMarket({
  question: "Will ETH hit $5000 in 2025?",
  endTime: endTime,
  initialLiquidity: "1000000", // 1 USDC (6 decimals)
});

console.log(`Market Created: ${conditionId}`);

The createMarket method handles collateral approval automatically if the factory's allowance is insufficient.

3. Trade (Buy / Sell)

// Buy YES outcome tokens with 10 USDC
const buyAmount = ethers.parseUnits("10", 6);
await client.trading.buy(conditionId, buyAmount, "YES");

// Sell 5 YES outcome tokens back for collateral
const sellAmount = ethers.parseUnits("5", 18); // Outcome tokens use 18 decimals
await client.trading.sell(conditionId, sellAmount, "YES");

Both buy and sell accept an optional minTokensOut / minCollateralOut parameter for slippage protection.

4. Fetch Market Info

const info = await client.market.getMarketInfo(conditionId);
console.log(info);

Returns an object containing:

| Field | Description | |---|---| | question | The market's question string | | endTime | Unix timestamp when trading closes | | isCreated | Whether the market exists on-chain | | isSettled | Whether the market has been resolved | | reserve | Total collateral held in the market | | collateral | Address of the collateral token | | winningToken | Token ID of the winning outcome (0 if unsettled) |

5. Get Market Prices

const prices = await client.market.getMarketPrices(conditionId);
console.log(prices.yesPricePercent); // e.g. "70.00%"
console.log(prices.noPricePercent);  // e.g. "30.00%"

6. Redeem Winnings

After a market is settled, holders of the winning outcome token can redeem their collateral:

const isResolved = await client.redemption.isResolved(conditionId);
if (isResolved) {
  await client.redemption.redeem(conditionId);
}

Configuration

The SDK ships with default contract addresses for Monad:

| Contract | Address | |---|---| | Factory | 0xDD5975B6D29C73e9e68FF128c1B5B4244986CF66 | | FeeManager | 0x9ac2dc5fB9a6b95CA9dEa27063f10e09e55fEfFa | | Collateral | 0x350035555E10d9AfAF1566AaebfCeD5BA6C27777 |

To override the defaults (e.g. for a different chain or custom deployment):

const client = new PNPClient({
  rpcUrl: "https://your-rpc-url.com",
  privateKey: "...",
  contractAddresses: {
    marketFactory: "0x...",
    usdcToken: "0x...",
    feeManager: "0x...",
  },
});

Development

1. Build the SDK: npm run build
2. Run the example script:

   export PRIVATE_KEY="your_hex_private_key"
   npx ts-node examples/quickstart.ts

Error Handling

The SDK includes custom error parsing for common contract reverts such as InvalidMarketEndTime, MarketTradingStopped, InvalidAddress, and InvalidTokenId. Read operations automatically retry on RPC rate-limit errors with exponential backoff (up to 5 attempts).