Overview The o1.exchange Trading API enables programmatic trading with enterprise-grade features including built-in MEV protection, Permit2 support for gasless approvals, and automatic slippage handling.
Key Benefits
MEV Protection : Private mempool routing to prevent sandwich attacksGasless Approvals : One-time Permit2 signatures for unlimited tradingAutomatic Slippage : Built-in slippage protection with customizable limits Prerequisites
Wallet Ethereum wallet with private key
Gas Fees ETH for transaction costs
Runtime Node.js environment
Quick Start 1. Generate API Key
Create API Key
Generate your secure API token for authentication
2. Create Transaction Batch Endpoint: POST https://api.o1.exchange/api/v2/orderHeaders: { "Authorization" : "Bearer <YOUR_API_TOKEN>" , "Content-Type" : "application/json" }
Body: { "signerAddress" : "0x..." , // Your wallet address "tokenAddress" : "0x..." , // Token contract address "uiAmount" : "1.0" , // Amount in human-readable format "direction" : "buy" , // "buy" or "sell" "slippageBps" : 300 , // Slippage in basis points (300 = 3%) "mevProtection" : true // Enable MEV protection }
{ "success" : true , "id" : "batch_123..." , "transactions" : [ { "id" : "tx_456..." , "unsigned" : { "to" : "0x..." , "data" : "0x..." , "value" : "0x..." , "gasLimit" : "0x..." , "chainId" : 1 }, "permit2" : { "eip712" : { "domain" : { ... }, "types" : { ... }, "values" : { ... } } } } ] }
3. Sign Transaction and Permit2
For each transaction in the response:
Sign Permit2 (if present):
Extract the EIP-712 typed data from permit2.eip712
Sign using wallet’s signTypedData method
Replace the signature placeholder in transaction data
Sign the transaction:
Create transaction object from the unsigned data
Sign using wallet’s signTransaction method
// Fixed signature placeholder - don't change const SIGNATURE_PLACEHOLDER = "42f68902113a2a579bcc207c91254c8516d921250e748c18a082d91d74908f8e9a05f27b72a030c6a42d77d0e0aab6fb09219b01a01e7b5b24e4f322ee1762ff1b" ; for ( const ctx of data . transactions ) { const unsignedTx = Transaction . from ( ctx . unsigned ); // Handle Permit2 signature if present if ( ctx ?. permit2 ?. eip712 ) { const { domain , types , values } = ctx . permit2 . eip712 ; const signature = await wallet . signTypedData ( domain , types , values ); // Replace placeholder with actual signature let txData = unsignedTx . data ; txData = txData . replace ( SIGNATURE_PLACEHOLDER , signature . slice ( 2 )); unsignedTx . data = txData ; } // Sign the transaction const signedTx = await wallet . signTransaction ( unsignedTx ); }
4. Submit Transaction Endpoint: POST https://api.o1.exchange/api/v2/order/completeHeaders: { "Authorization" : "Bearer <YOUR_API_TOKEN>" , "Content-Type" : "application/json" }
Body: { "id" : "batch_123..." , // Batch ID from create response "transactions" : [ { "id" : "tx_456..." , // Transaction ID "signed" : "0x..." , // Signed transaction hex "permit2" : { "eip712" : { "signature" : "0x..." // Permit2 signature } } } ] }
{ "success" : true , "transactions" : [ { "hash" : "0x..." , // Transaction hash "status" : "pending" , // Transaction status "tokenDelta" : "1000000" // Token balance change } ] }
Sample Scripts & Examples
Complete Sample Repository GitHub Repository: https://github.com/CohumanSpace/o1-api This repository contains complete sample scripts for using the o1.exchange API, including:
Interactive CLI trading application
Complete integration examples
Proper error handling patterns
Environment setup guides
Interactive Example
Complete CLI Trading App See execute-trade-interactive.js in the sample repository for a fully functional CLI trading application that demonstrates all integration steps with proper error handling and user interaction. Setup Environment Create a .env.local file:
EXECUTE_TRADE_PRIVATE_KEY=<YOUR_PRIVATE_KEY> EXECUTE_TRADE_API_TOKEN=<YOUR_API_TOKEN> EXECUTE_TRADE_BASE_URL=<API_BASE_URL> EXECUTE_TRADE_RPC_URL=<ETHEREUM_RPC_URL>
Run Interactive CLI node execute-trade-interactive.js
Token Address
Enter token contract address (e.g., 0x06ca615ac72a18e76b63bd4b5c320b6c8e291f8b)
Trade Direction
Choose buy or sell
Amount
Enter amount in ETH (for buy) or tokens (for sell)
Confirm
Review trade details and execute
Results
View balance changes after execution
Advanced Features
Permit2 Integration Gasless token approvals using EIP-712 signatures
Automatic signature placeholder replacement One-time approval for unlimited trading Reduced gas costs for frequent traders
MEV Protection Protection against sandwich attacks
Private mempool routing Reduced slippage from MEV bots Enable with mevProtection: true Slippage Control Specify slippageBps in basis points where 100 bps = 1% Recommendations:
Normal conditions: 300 bps (3%)Volatile tokens: 500-1000 bps (5-10%)Large trades: Increase as needed Error Handling Always implement proper error handling for:
Network connectivity issues
Insufficient balance or gas
Transaction reverts
API rate limiting
The interactive example includes comprehensive error handling patterns you can reference for your own implementation.
