Understanding Transaction Authorization
Before executing any token swaps on OKX DEX, users must authorize the OKX DEX router contract to access their wallet assets. This process adheres to the ERC-20 Token Standard, ensuring secure asset management during decentralized exchanges.
Key Concepts
- Authorization Requirement: Grants permission for smart contracts to handle specified token amounts
- Token Precision: Approval amounts must include token decimals (e.g., 1 USDT = 1000000 units)
API Endpoint
GET https://web3.okx.com/api/v5/dex/aggregator/approve-transactionRequired Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
chainIndex | String | Yes | Blockchain identifier (e.g., 1 for Ethereum) |
tokenContractAddress | String | Yes | ERC-20 token contract address |
approveAmount | String | Yes | Amount to authorize (including decimals) |
Response Structure
| Field | Type | Description |
|---|---|---|
data | String | Blockchain transaction call data |
dexContractAddress | String | OKX DEX router contract address |
gasLimit | String | Recommended gas limit |
gasPrice | String | Current gas price in wei |
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Implementation Guide
- Chain Selection: Verify correct
chainIndexfor your target blockchain - Amount Calculation: Convert human-readable amounts to token units
- Gas Management: Use returned
gasLimitandgasPricefor transaction cost estimation
Best Practices
- Always verify contract addresses before authorization
- Use conservative gas limits for failed transaction protection
- Monitor blockchain conditions for optimal gas pricing
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FAQ
Q: How often do I need to authorize tokens?
A: Typically once per token, unless you revoke permissions or change spending limits.
Q: What happens if I authorize too much gas?
A: Excess gas will be refunded, but setting appropriate limits prevents network congestion delays.
Q: Can I authorize multiple tokens simultaneously?
A: No, each token requires separate authorization transactions.
Q: How do I check existing allowances?
A: Use blockchain explorers or wallet interfaces to view approved contracts.
Q: What's the difference between approveAmount and gasLimit?
A: approveAmount specifies token quantity, while gasLimit defines computational resources for the transaction.
Q: Is authorization required for every trade?
A: Only first-time interactions with new tokens require approval.