Whoa! I remember the first time I accidentally approved an unlimited allowance to a shiny new DEX. Ouch. My instinct said “this is fine” and then my wallet showed otherwise. Initially I thought approvals were harmless, but then I watched a small balance disappear after a malicious contract drained it. Honestly, that moment changed how I interact with contracts.
Here’s the thing. Token approvals are the single most underrated attack vector in DeFi. Short story: you grant a contract permission to move tokens on your behalf, and if that permission is broad or never revoked, you’re exposed. This is basic, but people forget it because the UX nudges them toward “Approve” buttons that feel frictionless. On one hand, approvals enable convenient UX for DEX routing and aggregators. Though actually, unchecked approvals turn convenience into risk.
Let’s get practical. First, understand the two common approval patterns. One is the classic approve-to-infinite pattern—developers often prompt you to “approve unlimited” so you don’t sign every swap. It’s convenient. It is also risky. The safer pattern is approval-by-amount: give exactly what a contract needs for the single action, then revoke or let it expire. My bias: I always try to avoid infinite approvals unless I’m extremely comfortable with the counterparty.
Token allowance management: basic moves that actually matter
Okay, so check this out—there’s a small workflow that saves headaches. First, limit approvals to the smallest amount possible. Second, use an allowance manager to audit and revoke old permissions regularly. Third, prefer dapps that use EIP-2612 permits or signed approvals, because they reduce the number of on-chain approve transactions (and thus your exposure). Hmm…sounds simple, but people don’t do it.
Revoking is low effort. There are tools—built into many wallets and also available as standalone sites—that let you see which contracts can spend your tokens and revoke those allowances. Do it monthly. Or weekly if you trade a lot. I know that sounds like overkill. But in practice it’s the difference between a near-miss and a real compromise.
Another tip: split funds. Keep a main “hot” wallet for everyday trades and a cold or hardware wallet with long-term holdings. If you’re a frequent trader, use a smaller trading wallet with only the funds you intend to use, and keep the croc-size stash offline. I’m biased toward hardware-backed approvals for high-value ops. It’s extra friction, but worth it.
Also—don’t blindly trust every contract you interact with. Look at the contract address on a block explorer, check audits if available, and prefer established aggregators. Somethin’ about new shiny projects makes people relax their guard, and that’s when bad things happen…
MEV: what it is and how wallets help
MEV — miner (or now, maximizer) extractable value — is the value that searchers capture by re-ordering, including, or excluding transactions within a block. Sandwich attacks are a classic example. You submit a trade; a bot spots it in the mempool, front-runs with a buy, your swap moves price, the bot sells into your trade, and you eat the slippage. Annoying. Expensive. And avoidable to some extent.
Wallet-level MEV protection can help by using private relays, bundling transactions, or by submitting through relays that avoid public mempool exposure. Some wallets also simulate outcomes to warn you about potential front-running risk. Initially I thought these protections were marketing fluff, but after trying a few flows I saw a real reduction in sandwich attempts. Actually, wait—let me rephrase that: they reduce exposure in many common scenarios, but no solution is perfect.
On one hand, private relays reduce visibility to searchers. On the other, they can add trust into your flow because you’re depending on the relay operator. So, weigh the trade-offs. If you’re routing large trades, consider using DEX features like private liquidity routes, limit orders, or native aggregator options that submit via private channels.
Rabby’s approach bundles usability with these protections, offering transaction previews, approval controls, and MEV defenses so you get fewer surprises. If you want to try a wallet that centers approval management and MEV-aware routing, check out rabby wallet. I recommend giving its allowance dashboard a look and experimenting with its simulation/safety prompts before you commit big funds.
Practical checklist — before you hit approve
– Ask: Does this dapp need an infinite approval? If not, set a precise amount. Short approvals save headaches.
– Revoke old allowances periodically. Seriously. Make it a habit.
– Use a dedicated trading wallet for routine interactions. Keep savings off the hot path.
– Prefer dapps that support signed permits (EIP-2612). Fewer approvals, lower exposure.
– If trading big, prefer private submission paths or limit orders to avoid mempool leaks.
– Use hardware wallets for signing approvals that spend large amounts. It’s slower, but safer.
One more nuance: some tokens implement non-standard approve patterns or have buggy contracts. Before approving, glance at the token contract if you can. If a token has strange code or lacks standard events, treat it as higher risk. This is geeky, I know. But it’s the sort of detail that saves you later.
FAQ
How often should I revoke approvals?
Monthly for casual users; weekly or after any one-off interaction for active traders. If it was a single swap, revoke it once done. Small effort. Big upside.
Does MEV protection cost more gas?
Sometimes. Private relays or bundled submissions can change how fees are handled. But the saved slippage from avoiding a sandwich can more than offset fee differences on larger trades. On tiny trades it’s less worth it.
What’s the simplest immediate step I can take?
Open your wallet’s allowance or permissions view and revoke anything you don’t recognize. Then use a separate wallet for trading. That alone stops a ton of worst-case scenarios.