Okay, so picture this—you’re on a Saturday, crypto markets are sleepy, and you approve a token so you can zap into a pool. Quick click. Done. Then, weeks later, some contract drains your bag. Wow. That gut-sink feeling? I know it. Seriously?
My instinct said “just revoke it later”, but that rarely happens. Initially I thought approvals were a minor UX annoyance, but then I watched a friend lose a mid-sized position because of an ERC-20 allowance left wide open. On one hand, approvals are what make composability possible. Though actually, the default mechanic—perpetual unlimited approvals—creates an attack surface that too many people ignore.
Here’s the thing. Token approvals are permissions. They let contracts pull tokens from your wallet, and most users treat them like generic settings instead of security primitives. Short approvals, recurring checks, and an approval hygiene routine change the game. My approach is pragmatic: minimize standing allowances, batch revocations when gas is cheap, and use tools designed for multi-chain management. I’m biased toward wallets that make this visible and easy.
What actually goes wrong with approvals
Most ERC-20 tokens implement approve/transferFrom semantics. That alone is fine. The problem is UX defaults. Wallets and dApps prompt for one-time approvals but often suggest “infinite approval”. Developers do this to avoid repeated gas costs for frequent interactions. The result: lots of unlimited allowances sitting on-chain, waiting for a bad actor or a buggy contract to exploit them.
Whoa! When someone vector-hops into a protocol through a flashloan or oracle trick, those unlimited approvals become an automatic siphon. On the technical side, an attacker either reuses a compromised contract or tricks the user into interacting with an attacker-controlled contract. Practically, the token never leaves the chain of permissions—they just pull your approved tokens out. It’s ugly.
There are three common patterns I see. One: infinite approvals granted casually. Two: approvals granted to aggregator contracts that later change behavior. Three: users who approve dozens of tokens across multiple chains and never audit allowances. Each pattern is a cliff. You can patch some of them with better UX, but the root cause is permission creep.
Simple, effective defenses
Start small. Revoke unlimited approvals. That is step one. Seriously. Set allowances to exact amounts when possible. If you must set a recurring allowance, have a revocation schedule in your calendar. Sounds basic, but it works.
Next, use a wallet that surfaces approvals clearly and makes revocation one-click across chains. I like tools that summarize allowances, show the exact spender addresses, and estimate the gas cost for revoking. For multi-chain use, that visibility is essential. One wallet I keep coming back to is rabby because it highlights approvals and groups actions by chain, which saves time and reduces errors. I’m not claiming it’s perfect—no wallet is—but it helps me sleep better.
Optimize gas spend. Batch revocations during low-fee windows. Use gas trackers and native L2s when possible. On Ethereum mainnet, plan revocations around weekends or off-peak hours. On some layer-2s, gas is cheap enough to afford tighter permission hygiene. And hey—if you’re moving funds between chains, revoke approvals on the source chain first. That step gets skipped way too often.
My process—broken down—is simple: audit, reduce, schedule, automate where safe. Audit: list all approvals by chain. Reduce: set limits or revoke. Schedule: pick low-fee times for any on-chain changes. Automate: use scripts or guarded automations only if you understand the risks. Initially I scripted an auto-revoker and it saved me gas. Actually, wait—let me rephrase that—my script almost cost me gas when a token I owned re-used the spender for legitimate reasons, so I added whitelists. Lesson learned.
Gas optimization tactics that don’t feel sketchy
Gas is a behavioral tax. If revoking costs more than the potential loss, people won’t revoke. So reduce the friction. Combine revocations into a single transaction where protocols support it. Use providers with sponsored transactions or bundle transactions when it’s safe. On chains that support meta-transactions, you can sometimes delegate gas to a relayer, but watch for new trust vectors there.
Timing matters. Use mempool trackers to spot cheap windows. When you see a dip in gas prices, hit the revoke. Also, for recurrent approvals, consider using “permit” style tokens (EIP-2612) where the approval happens off-chain via a signed message, cutting on-chain approvals entirely. Not every token supports permits, but when they do, it’s cleaner and cheaper.
Also, don’t forget non-token gas tricks. For example, renouncing an approval by transferring tokens to a burn address is a hacky pattern some use for small amounts—it’s not elegant, but for dust it can be pragmatic. I’m not endorsing reckless moves—just saying there are workarounds when you weigh risk vs reward.
The human side: habits that save wallets
Habits beat heroic saves. Set a weekly or monthly “allowance audit” in your calendar. Get a checklist. Use a dedicated device or browser profile for DeFi interactions to reduce phishing risk. Keep a short whitelist of contracts you trust—yes, that requires maintenance, but it’s way better than blind trust.
Oh, and by the way… educate the folks you trade with. Send a short how-to to your trading group or DAO members. Make approval hygiene part of onboarding. People are embarrassed after a loss and then too quiet. Break that cycle.
On the psychology front, warnings that are too frequent become background noise. Design your process so the warnings are meaningful—revocation reminders when you’ve spent tokens, or when a new spender address appears, for example. This is where wallet UX can materially change security outcomes.
FAQ
What if I accidentally revoke a legitimate allowance?
Recovering is straightforward if you still control the wallet: re-approve the contract for the needed amount. Double-check spender addresses before re-approving. And add that contract to a trusted list so you don’t revoke it again by mistake.
Is infinite approval ever acceptable?
Only in narrow, high-frequency scenarios where gas costs dwarf the value at risk and you fully trust the spender contract’s immutability. Even then, maintain monitoring. My rule: treat infinite approvals as a temporary convenience, not a default.
How do I audit approvals across multiple chains?
Use wallets or explorers that index allowances by chain. Export the list and prioritize high-value approvals. If you manage many addresses, automate with a script that queries known token contracts and compiles an approvals ledger.
