Blog

Wow!

I was poking around a failed swap last week on mainnet and something felt off.

My instinct said never trust a blind confirm.

Initially I thought it was just sloppy UI, but replaying the tx revealed calldata that routed approvals through a proxy with transfer hooks, and that single detail explained the drain that followed.

That kind of mess makes you rethink how much trust you place in both wallets and aggregators.

Whoa!

Experienced DeFi users often skip the simulation step because they assume the wallet or aggregator will catch errors.

On the other hand the simulation is the only place where you can see how contracts will behave before gas is burned and state changes are irreversible.

Seriously? No kidding—skip simulation and you might sign an approval that lets a malicious contract siphon tokens via a transfer hook.

I’ve built my workflow around simulation and it has stopped a handful of near-misses for me.

Okay, so check this out—

rabby wallet integrates transaction simulation into the confirm flow which is rare among browser wallets.

That feature surfaces state diffs, estimated gas, internal calls and potential reverts so you can reject risky ops confidently.

Initially I thought on-chain simulation would be glacial, but in practice it’s fast and often mirrors mainnet behavior pretty closely.

There are caveats—simulations depend on RPC accuracy and mempool nuance can differ, so you still need to interpret results.

Hmm…

When you simulate, set the block to pending because mempool state influences frontrunning risk and failing conditions.

Also check for delegatecall and unusual approve patterns since those are common red flags for malicious flows.

My instinct said reading raw calldata was overkill, but after messy trades I started spot-checking function selectors and addresses in input data and that saved me headaches.

On wallets prefer hardware-backed signing or session-scoped approvals and limit approvals to specific amounts whenever possible.

Really?

WalletConnect is convenient but also a vector if session setup is sloppy or you accept a URI without verifying origin.

The protocol uses a URI to pair a dapp and wallet, and that handshake must be verified out-of-band or via QR scanning to avoid MITM session hijacks.

Initially I trusted persistent sessions; later I found an old connection with broad permissions and that was my fault for not pruning scopes—lesson learned.

So prune sessions regularly and always verify chain IDs before signing anything important.

Whoa!

Rabby offers clear session management that lists connected sites and their permissions—this transparency matters when you juggle many dapps.

It shows chain and pending requests and lets you approve by method so you don’t accidentally sign a dangerous composite transaction.

I’m biased, but that granular control is why I use this wallet as my daily driver when I’m on ephemeral sessions or doing multi-step flows.

Also, somethin’ about the UX feels calmer—less hype, fewer deceptive button labels.

Hmm…

Use simulation to estimate gas and slippage then nudge gas to stay competitive without overpaying; it’s a small art and a necessary one.

For multi-call interactions, run a dry-run on a local fork or rely on the wallet’s simulation to detect reentrancy or unexpected token transfers before you hit confirm.

Okay, check this out—if a simulation shows internal swaps or approvals you didn’t trigger, that’s a red flag for transfer hooks or tax tokens and you should back out immediately.

Be mindful of nonce management for batched txs because a failed early tx can break the whole sequence and leave you stuck under high gas.

Wow!

Quick checklist: simulate, inspect calldata, verify approve amounts, confirm chain, and check session scopes.

Don’t sign approve-all unless absolutely necessary; when you must, set a finite allowance or use permit signatures where the protocol supports them.

Also consider front-running protections like gas ceilings, private relayers, or transaction bundlers to mitigate sandwich attacks when trading large positions.

I’m not 100% sure every relayer is trustworthy, but used carefully they can help reduce MEV exposure.

Seriously?

I once watched a swap drain a small position because an aggregator routed through a token with malicious transfer hooks and the user never simulated the call trace.

Initially I blamed the aggregator, though actually the wallet confirm flow didn’t show internal calls cleanly and the user didn’t check details—shared responsibility all around.

That pushed me to favor wallets that surface exact contract calls and let me decline suspicious internal operations without guessing.

It bugs me that many wallets still treat simulation as optional rather than a standard safety step.

Whoa!

My workflow: connect via WalletConnect for session isolation or use the extension depending on threat model; simulate multi-hop swaps; review diffs; limit approvals.

If a dapp asks for unlimited allowance I pause and either set a specific allowance or use a permit if available, because permits remove the need for open approvals in many cases.

Initially I thought permits were rare, but they’re now common on major protocols and they meaningfully reduce approval risk when implemented correctly.

For hardware users pair your device through Rabby’s UI for the extra verification step and use session expiration aggressively.

Hmm…

There’s no perfect defense; adversaries adapt and the UX arms race keeps moving forward.

On one hand simulation gives visibility, though actually it can lull folks into overconfidence if they don’t understand pending-state differences and RPC pitfalls.

I’m biased toward wallets that force a second glance at internal calls and make session management obvious—visual friction helps security here.

So adopt a cautious posture, train your muscle memory to pause, and keep at least one cold wallet for large holdings or emergency recovery.

Practical note on Rabby wallet

Okay, so quick note—if you want to test this workflow start by installing rabby wallet and enabling the transaction simulation toggle in settings.

The wallet will show an execution trace and allow you to inspect internal transfers, which is indispensable for tokens with obscure hooks or tax logic.

Initially I thought toggling simulation would slow confirmations, but it barely adds overhead and the safety payoff is well worth it.

Try a small dry-run and compare the simulation to the actual result so you get familiar with how it reports slippage and internal calls.

Over time you’ll build mental models of patterns that indicate benign complexity versus malicious behavior—it’s a skill that pays dividends.