Execution Service - Complete API Reference

Execute trades on Polymarket and Kalshi with slippage protection, maker orders, and order management.

Supported Platforms

Platform Order Types Features

Polymarket Limit, Market, Maker -0.5% maker rebate, GTC/FOK

Kalshi Limit, Market US regulated

Chat Commands

Place Orders

/execute buy poly <market> YES 100 @ 0.52 # Limit buy on Polymarket /execute sell kalshi <market> NO 50 @ 0.48 # Limit sell on Kalshi /execute market-buy poly <market> YES 100 # Market buy /execute market-sell poly <market> NO 50 # Market sell

Maker Orders (Rebates)

/execute maker-buy poly <market> YES 100 @ 0.52 # Post-only buy /execute maker-sell poly <market> NO 50 @ 0.48 # Post-only sell

Protected Orders (Slippage Protection)

/execute protected-buy poly <market> YES 100 --max-slippage 1% /execute protected-sell poly <market> NO 50 --max-slippage 0.5%

Order Management

/orders open # View open orders /orders open poly # Open orders on Polymarket /orders cancel <order-id> # Cancel specific order /orders cancel-all # Cancel all open orders /orders cancel-all poly # Cancel all on Polymarket

Slippage Estimation

/estimate-slippage poly <market> buy 1000 # Estimate slippage for $1000 buy /estimate-slippage kalshi <market> sell 500 # Estimate for $500 sell

TypeScript API Reference

Create Execution Service

import { createExecutionService } from 'clodds/execution';

const executor = createExecutionService({ polymarket: { apiKey: process.env.POLY_API_KEY, apiSecret: process.env.POLY_API_SECRET, passphrase: process.env.POLY_API_PASSPHRASE, privateKey: process.env.PRIVATE_KEY, }, kalshi: { apiKey: process.env.KALSHI_API_KEY, privateKey: process.env.KALSHI_PRIVATE_KEY, },

// Defaults defaultSlippageTolerance: 0.5, // 0.5% autoLogTrades: true, });

Limit Orders

// Buy limit order const order = await executor.buyLimit({ platform: 'polymarket', marketId: 'market-123', side: 'YES', size: 100, // $100 price: 0.52, // 52 cents timeInForce: 'GTC', // Good-til-cancel });

console.log(Order placed: ${order.orderId}); console.log(Status: ${order.status});

// Sell limit order const sellOrder = await executor.sellLimit({ platform: 'polymarket', marketId: 'market-123', side: 'YES', size: 100, price: 0.55, });

Market Orders

// Market buy - executes immediately at best price const order = await executor.marketBuy({ platform: 'polymarket', marketId: 'market-123', side: 'YES', size: 100, });

console.log(Filled at: ${order.avgFillPrice}); console.log(Filled size: ${order.filledSize});

// Market sell const sellOrder = await executor.marketSell({ platform: 'kalshi', marketId: 'TRUMP-WIN', side: 'YES', size: 50, });

Maker Orders (Post-Only)

// Maker buy - only executes as maker (gets rebate) const order = await executor.makerBuy({ platform: 'polymarket', marketId: 'market-123', side: 'YES', size: 100, price: 0.52, });

// Will be rejected if it would execute immediately as taker if (order.status === 'rejected') { console.log('Price too aggressive - would be taker'); }

// Maker sell const sellOrder = await executor.makerSell({ platform: 'polymarket', marketId: 'market-123', side: 'NO', size: 50, price: 0.48, });

Protected Orders (Slippage Protection)

// Protected buy - checks slippage before executing const order = await executor.protectedBuy({ platform: 'polymarket', marketId: 'market-123', side: 'YES', size: 100, maxSlippage: 0.5, // 0.5% max slippage });

if (order.status === 'rejected') { console.log(Rejected: slippage would be ${order.estimatedSlippage}%); } else { console.log(Executed with ${order.actualSlippage}% slippage); }

// Protected sell const sellOrder = await executor.protectedSell({ platform: 'kalshi', marketId: 'TRUMP-WIN', side: 'YES', size: 50, maxSlippage: 1, });

Order Management

// Cancel specific order await executor.cancelOrder('polymarket', orderId);

// Cancel all orders on platform await executor.cancelAllOrders('polymarket');

// Cancel all orders for a market await executor.cancelAllOrders('polymarket', { marketId: 'market-123' });

// Get open orders const openOrders = await executor.getOpenOrders('polymarket');

for (const order of openOrders) { console.log(${order.orderId}: ${order.side} ${order.size} @ ${order.price}); console.log( Status: ${order.status}); console.log( Filled: ${order.filledSize}/${order.size}); }

Slippage Estimation

// Estimate slippage before executing const estimate = await executor.estimateSlippage({ platform: 'polymarket', marketId: 'market-123', side: 'buy', size: 1000, });

console.log(For $1000 buy:); console.log( Avg fill price: ${estimate.avgFillPrice}); console.log( Expected slippage: ${estimate.slippagePct}%); console.log( Total filled: ${estimate.totalFilled}); console.log( Levels consumed: ${estimate.levelsConsumed});

Order Types

Type Description Best For

Limit Execute at specific price or better Price-sensitive orders

Market Execute immediately at best available Urgent execution

Maker Post-only, gets rebate Collecting rebates

Protected Checks slippage before executing Large orders

Time In Force

Value Description

GTC Good-til-cancel (default)

FOK Fill-or-kill - all or nothing

IOC Immediate-or-cancel - fill what you can

Fee Structure

Polymarket (Verified Jan 2026)

• Most markets: 0% maker, 0% taker (zero fees)

• 15-min crypto markets: Dynamic taker fees up to ~3% at 50/50 odds; makers eligible for rebate program

Kalshi

• Taker: Formula-based ~1.2% average, capped at ~2%

• Maker: ~0.17% (formula-based)

Best Practices

• Use maker orders when possible - Pay no fees on Polymarket (most markets)

• Check slippage before large orders

• Use protected orders for size > $500

• Set appropriate timeInForce - GTC for patient orders, FOK for all-or-nothing

• Monitor open orders - Cancel stale orders

• Start small - Test with small sizes first