Investing in crypto activities can be exciting, but it’s also full of risks. Approving the wrong token or interacting with a dangerous smart contract can lead to losses that are hard to recover, if at all. That’s why it’s vital to check smart contract interactions before you sign anything.
In 2025, roughly 8.5% of total crypto theft losses resulted from smart contract flaws and code-level vulnerabilities, and these thefts totaled about $500M across the crypto ecosystem.
By understanding what smart contract interactions are, knowing how to spot red flags, and using trusted verification tools, you can safely invest in crypto without putting your assets at risk.
Executive Summary
- Check smart contract interactions using block explorers, approval checkers, transaction simulators, and wallet tools to verify contracts before signing.
- In 2025, smart contract flaws caused $500M in crypto losses.
- Use smart contract verification tools before signing any contracts to ensure they’re safe.
- Always review smart contract approvals and be aware of red flags before interacting.
Why Test Smart Contract Interactions?
Testing or checking a smart contract’s interactions helps you confirm that a contract behaves the way you expect before you trust it with your digital assets.
The point of doing this is to avoid scams, prevent unwanted approvals, and make sure you’re not interacting with a contract that could drain your wallet.
The crypto ecosystem has seen many malicious contracts disguised as trading tools, airdrops, or trending tokens. Developers design some as honeypots, where you can buy but not sell. Others ask for unlimited approval permissions, which allows them to drain your tokens once you click ‘Approve’.
Testing interactions, especially when it comes to dApps or unfamiliar tokens, helps you verify whether the contract is legitimate before you commit your funds.
Also, testing smart contracts reduces the risk of losing tokens through hidden permissions or interacting with abandoned or compromised protocols.
Developers test interactions for different reasons. They may audit contracts for vulnerabilities like reentrancy attacks (which were responsible for around 40% of all smart contract breaches in 2025), poor access controls, or risky delegate calls.
They also check how contracts behave together. For example, whether updating a staking contract correctly updates a rewards contract.
What Are Smart Contract Interactions?
Smart contract interactions are any actions your wallet takes when it communicates with a blockchain-based application, like confirming a swap, giving a token approval, minting an NFT, or staking tokens.
To put it simply, anytime you click ‘Approve’, ‘Sign’, or ‘Confirm’ on a decentralized app (dApp), your wallet is interacting with a smart contract behind the scenes.
These interactions happen because most crypto apps rely on smart contracts to automate processes like trading and transferring tokens. This usually looks like a pop-up in a wallet asking you to approve something.
But each type of interaction gives the contract different levels of permission, which is why understanding them matters for security.
The most common interactions include:
- Token approvals: Allowing a contract to access or move specific tokens from your wallet.
- Token transfers: Sending tokens directly to a contract, often during deposits or swaps.
- Signatures: Signing a message that verifies your identity to the dApp, sometimes without costing gas fees.
Of all of these, token approvals are the riskiest interaction. A single approval can give a bad contract unlimited access to a specific token, which can let it drain your entire balance of the asset.
Even older approvals you’ve forgotten about can become dangerous if the protocol is later hacked or abandoned.
Many wallet drains happen not at the moment of the interaction, but months or years later, when attackers exploit past approvals that a user never revoked.
Legitimate Tools for Checking Smart Contract Interactions
There are a few tools that can help you review and verify what a smart contract is trying to do before you approve anything. Let’s take a closer look at these.
Block Explorers
Block Explorers like Etherscan, BscScan, and Solscan are free public tools that let anyone look inside a blockchain and understand what a smart contract has been doing.
Each network has its own explorer, so you’ll need to use one that matches the chain you’re interacting with. For example, Etherscan for Ethereum or Solscan for Solana.
Block explorers are one of the simplest ways to verify whether a contract looks legitimate. By pasting a contract address into the tool’s search bar, you can quickly and easily see details like:
- The contract’s age
- Its creator
- Whether the code is verified (meaning the developer has publicly uploaded the source code)
- The number of token holders
- Recent interactions
- Transaction volume
- If the contract has been upgraded or paused
Explorers also help you identify red flags. A newly deployed contract with almost no holders or minimal activity can indicate a higher risk. On the other hand, established contracts with long histories and consistent wallet interactions usually mean more trustworthy projects.
Because block explorers are open to everyone and often don’t require you to log in, they’re one of the easiest first steps when you want to check a smart contract.
Approval Checkers
Approval checkers like Revoke.cash and Unrekt.net let you see which smart contracts currently have permission to move your tokens.
These platforms scan your wallet and list every active approval you’ve granted, even ones from years ago that you may have forgotten about.
These are some of the most important security tools to use because token approvals are the main way malicious contracts drain wallets.
You can connect your wallet, and the tool instantly shows you:
- Which contracts have access to your tokens
- What type of permission they have
- When the approval was granted
- Options to revoke permissions directly from the interface
They’re also chain-specific, which means you’ll need to use a platform that supports the network you’re checking, like Ethereum or Polygon. Most tools cover major chains, but smaller networks might have limited options.
Be aware that approval checkers can’t tell you whether a contract is good or bad. They only show the permissions you’ve already given. But regularly reviewing and revoking old or unused approvals helps prevent abandoned or compromised protocols.
Transaction Simulators
Transaction simulators like Tenderly and Pocket Universe let you preview what a transaction will do before you approve it on-chain.
These tools run what’s called a dry simulation of your intended action, like swapping tokens or claiming rewards, to show you the likely outcome without spending gas or risking your assets.
This is especially helpful when you’re interacting with dApps or unfamiliar tokens, as well as for large transactions where mistakes could end up costing you a lot.
Transaction simulators can show you:
- Which contract functions will be called
- How your token balances will change
- Whether the transaction will succeed or fail
- If the contract is attempting unexpected actions, like transferring tokens you didn’t intend to move
An advantage of these tools is being able to identify suspicious behavior before it turns into negative consequences. If a simulator shows what seems to be a harmless action that tries to drain your token balance or alter approvals, you can stop the transaction safely.
However, simulators do have limitations. They rely on current blockchain data, so the tools may not always reflect very new contracts. Some tools also need you to connect your wallet or paste your transaction data manually.
Built-In Wallet Tools
Many crypto wallets like Best Wallet include built-in features that let you review basic smart contract details before you sign anything.
When a dApp asks you to interact with a contract, your wallet usually displays the following:
- Contract address
- The function being called
- In the case of approvals, the amount of tokens the contract is requesting access to
Even this simple information might help you to verify if the interaction looks legitimate.
For example, if you’re approving a token swap, you’ll likely see an approval for that specific token, not a random asset or unusually high approval amount. Wallets also often let you copy the contract address so you can paste it into a block explorer for verification.
Some wallets have transaction previews, warnings about risky permissions, and even light transaction simulators that flag unexpected behavior.
These aren’t perfect substitutes for full simulators or approval checkers, but they do give you extra protection.
Built-in wallet tools provide an important first checkpoint because they help you identify red flags before a malicious contract has a chance to access your funds.
Red Flags in Smart Contract Interactions
When you’re checking smart contract interactions, some warning signs can help you identify potentially dangerous or malicious contracts. Here are the most important red flags to be aware of:
- Unverified contracts: Contracts without verified source code could make it impossible to confirm what the code does. Interacting with these contracts is risky.
- New or low-activity contracts: Very recently launched contracts or those with few holders and transactions are often untested and could even be smart contract scams.
- Unusual permission requests: Requests for unlimited approvals or access to unrelated tokens are a significant warning sign.
- Copycat contracts: Fake versions of popular tokens or projects can trick users into interacting with malicious code. Always ensure you double-check contract addresses.
- High approval amounts for small transactions: Giving a contract unlimited access when you only need a small amount can lead to risks.
- Lack of sell interactions: If a token can be bought but not sold (honeypots), it’s designed to trap funds.
- Suspicious transaction patterns: Frequent, unexplained transfers or interactions with unknown addresses can indicate past or potential exploits.
- Abandoned or inactive protocols: Old contracts with forgotten approvals can become a risk if the project is later compromised.
How to Check Smart Contract Interactions on Block Explorer?
Checking smart contract interactions with a block explorer is simple. If you’re wondering how to check contract interactions, here’s an example using Etherscan.
- Find the contract address:
Look for it on the project’s website, whitepaper, or official social media posts. Always double-check to avoid copycat scams.
Source: Snorter Token
- Open the block explorer:
Navigate to the official Etherscan website.
Source: Etherscan
- Search for the contract:
Paste the contract address into the search bar and open its relevant page.
Source: Etherscan
- Review the contract’s activity:
Check key details like the age of the contract, transaction history, token holders, and recent interactions to spot unusual or suspicious activity.
Source: Etherscan
How to Check Your Wallet’s Active Approvals
Aside from checking specific smart contracts before you interact with them, another safety step is to check the contracts that already have access to your wallet. Here’s an example of how to do this using Revoke.cash.
- Visit the official Revoke.cash website and connect your wallet:
Navigate to the Revoke.cash website, click the ‘Connect Wallet’ button in the top right-hand corner, and select your wallet type. Log in to your wallet and give Revoke.cash access.
Source: Revoke
- Select the network:
Use the network selection dropdown menu to choose the blockchain network you want to check. - Review your approvals:
A list of active tokens and NFT approvals linked to your wallet address will be displayed. The list will include the spender address and the approved amount.
Source: Revoke
- Revoke access:
To revoke any of your approvals, find the entry you want to remove and click the ‘Revoke’ button next to it.
Rounding Off Our Guide to Smart Contract Security
Smart contract interactions are a regular part of using crypto, but they come with risks if you aren’t careful, hence the importance of smart contract security. Tools like block explorers, approval checkers, transaction simulators, and built-in wallet features make it easier for you to verify contracts before signing.
It’s vital to always review and verify smart contracts before interacting with them. Using platforms like Best Wallet’s built-in tools is the best first step. Pay attention to red flags, monitor older approvals, and only use trusted tools to stay informed.
FAQs
1. What is a smart contract interaction?
A smart contract interaction happens whenever your crypto wallet communicates with a blockchain-based contract, like approving tokens, swapping assets, or staking. It usually displays as a ‘Sign’ or ‘Approve’ request in your wallet, and each interaction gives the contract-specific permissions that can affect your tokens.
2. Can I get hacked by connecting my wallet to a website?
Yes, connecting to a malicious website can be risky. While connecting alone usually won’t drain your funds, approving token permissions or signing transactions for unsafe contracts can allow attackers to access your tokens.
3. Why check smart contract interactions?
Checking smart contract interactions helps you avoid scams, honeypots, or malicious approvals. By reviewing permissions and contract activity, you reduce the risk of losing tokens to malicious contracts or abandoned projects, especially when you’re using new decentralized apps (dApps).
4. Can AI audit smart contracts?
Yes, AI can help you with a smart contract audit for obvious issues or common vulnerabilities, but it can’t guarantee your safety. Human review and using verification tools are necessary to ensure smart contracts are secure before you interact with them.
