Security & Operational Guidance

Evix is designed with minimal surface area and on-chain enforcement. This page covers best practices for secure integration.

On-Chain Protections

The Evix contract enforces safety checks at the contract level — these cannot be bypassed by the SDK or caller:

Protection	Mechanism	Error
Deadline enforcement	Reverts if block.timestamp > deadline	DeadlineExceeded()
Slippage protection	Reverts if output < minAmountOut	InsufficientOutput(amountOut, minAmountOut)
Input validation	Reverts if amountIn == 0	InvalidAmountIn()
Recipient validation	Reverts if recipient == address(0)	InvalidRecipient()
Pair access control	Reverts if pair not allowlisted	UnsupportedPair(tokenIn, tokenOut)

Best Practices

Always set minAmountOut

Never use minAmountOut: 0 in production transactions. This leaves the swap completely unprotected against price movement and MEV.

// Bad — no slippage protection
const result = await evix.swap({
  ...params,
  minAmountOut: 0n, // DANGEROUS in production
});

// Good — 0.5% slippage tolerance
const expected = await evix.simulateSwap(params);
const minOut = expected - (expected * 50n) / 10_000n;
const result = await evix.swap({
  ...params,
  minAmountOut: minOut,
});

Use tight deadlines

Short deadlines prevent stale transactions from landing in unfavorable conditions.

Use Case	Recommended Deadline
Trading bots	15–30 seconds
Backend services	30–60 seconds
User-facing flows	60–120 seconds

Simulate before executing

Simulation catches problems before gas is spent:

• Unsupported pairs
• Invalid amounts
• Stale pricing
• Contract-level reverts

// Always simulate first
const expected = await evix.simulateSwap(params);

// Then execute with the simulation result informing your minAmountOut

Validate recipients

Ensure the recipient address is correctly derived and never user-controlled without validation. A malicious or incorrect recipient means tokens are sent to the wrong address with no recourse.

Maintain deployment mappings

For multi-chain or multi-customer systems, maintain explicit configuration:

const deployments: Record<string, EvixDeployment> = {
  "customer-a-base": {
    chainId: 8453,
    contractAddress: "0x...",
    supportedPairs: [["0x...", "0x..."]],
  },
  "customer-a-arbitrum": {
    chainId: 42161,
    contractAddress: "0x...",
    supportedPairs: [["0x...", "0x..."]],
  },
};

Operational Guidance

Token Approvals

Before swapping, the Evix contract must be approved to spend tokenIn:

// Approve exact amount (recommended)
await walletClient.writeContract({
  address: tokenIn,
  abi: erc20Abi,
  functionName: "approve",
  args: [evixAddress, amountIn],
});

tip

Consider using exact approvals rather than type(uint256).max to minimize approval surface.

Error Handling

Handle all revert cases explicitly:

try {
  const result = await evix.swap(params);
} catch (error) {
  if (error.message.includes("DeadlineExceeded")) {
    // Transaction was too slow — consider shorter deadlines
  } else if (error.message.includes("InsufficientOutput")) {
    // Price moved beyond slippage tolerance — re-simulate and retry
  } else if (error.message.includes("UnsupportedPair")) {
    // Pair not enabled on this deployment — check configuration
  }
}

Monitoring

For production integrations, monitor:

• Swap events — Track execution via the Swap event
• Revert rates — High revert rates indicate stale pricing or tight slippage
• Gas costs — Monitor gas consumption across chains
• Output quality — Compare actual output to simulated output over time