Before any signature: the contract address decides it
A main wallet should not be connected to Arbswap until its exact spender and swap contracts can be independently verified on the selected network; a quote, dashboard, or wallet prompt is not that verification.
This is the useful question behind an unfamiliar trading page: not whether it displays an opportunity, but whether the wallet is being asked to authorize a known contract for a limited, understandable action. If the page does not expose the contract addresses, the chain, the route, and the final transaction details, the fastest safe answer is to stop before signing.
Three wallet prompts that must be rejected
A request for a seed phrase, private key, recovery phrase, remote-control extension, or an unexpected signature must end the session. None is required to connect an ordinary EVM wallet to a decentralized application.
- Unknown chain: a network switch is not harmless when the token, explorer, and contract address cannot be checked on that network.
- Unlimited token access: an approval for the maximum integer is broader than a single trade and should not be accepted merely for convenience.
- Unreadable transaction: if the wallet cannot show the recipient, token amount, value, and method clearly enough to assess, there is no reason to approve it.
A wallet connection usually reveals a public address; it does not itself move funds. The dangerous boundary is a signed approval or transaction. Disconnecting later does not cancel an approval already written on-chain.
A 90-second check: read the transaction before accepting
The contract address, not the interface, is the object that receives permission. A careful user can make the decision quickly:
- Connect no wallet yet. Select the intended chain and find the displayed router, executor, or spender address.
- Paste that address into the appropriate block explorer and confirm that it is a contract, that its source is verified where possible, and that its activity makes sense for the claimed function.
- Open the wallet prompt only after that check. Compare its
toaddress with the verified address and inspect whether it callsapprove,permit, or a swap method. - For an approval, set the smallest amount that can complete the intended trade. If the wallet permits a custom allowance, use it.
- Confirm the output token, minimum received amount, gas cost, and expiry. A quote that changes materially or a transaction that reverts is a reason to cancel, not to raise slippage blindly.
An ERC-20 allowance is the permission that lets a named spender move up to a set amount of a token through transferFrom. The ERC-20 standard includes the approve, allowance, and transferFrom interfaces; they are not interchangeable with simply connecting a wallet.
Main wallet, test wallet, or no wallet: compare the real choices
The least costly choice is the one that limits exposure before any asset approval exists.
| Option | What it exposes | Time cost | When it fits |
|---|---|---|---|
| Primary wallet | Its balances and any approved tokens | Lowest | Only after the contracts and transaction are independently verified |
| Separate capped wallet | Only the funds deliberately placed there | Low | A small, testable interaction with an unfamiliar interface |
| No connection | Nothing | None | No contract address, unclear approval, or a route that cannot be checked |
A primary wallet fits a routine interaction with contracts the user already understands. A separate wallet fits a controlled test with funds small enough to lose. No connection fits every case where the interface asks for trust without supplying the information needed to verify it.
MEV changes the economics even when the contract is genuine
A real swap contract does not turn a claimed arbitrage spread into a reliable retail trade. On public networks, pending transactions can be observed and reordered; Ethereum.org explains how DEX arbitrage works through price differences across exchanges and why the activity is intensely competitive.
“DEX arbitrage, liquidations, and sandwich trading are all very well-known MEV opportunities and are unlikely to be profitable for new searchers.” — Ethereum.org
That matters because an apparent spread can disappear between quote and inclusion. Gas, price impact, slippage, liquidity depth, failed transactions, and other searchers can consume the margin. An interface may calculate a route correctly at one instant and still produce a worse execution or no execution in the next block.
After an approval: revocation is a transaction, not a disconnect
An existing allowance should be checked whenever a wallet has interacted with an unfamiliar trading contract. The owner can revoke it by submitting a new on-chain approval of zero to the same token and spender. That costs gas, but it removes the spender’s remaining ERC-20 authority.
The shortest safe path is therefore simple: verify the exact contract first, approve only a capped amount if a test is justified, and do not connect at all when the route cannot be inspected.