Why approvals exist
Tokens are controlled by smart contracts. If you want a decentralized exchange to swap your token, the exchange contract needs permission to move that token from your wallet. The approval is the permission step. The swap is a separate action.
This two-step flow is normal. The risk comes from approving the wrong contract or approving more than needed.
Limited vs unlimited approvals
A limited approval allows a contract to spend a specific amount. An unlimited approval allows a contract to spend any amount of that token until permission is revoked. Unlimited approvals are convenient because you do not approve every time, but they increase risk if the contract is exploited or malicious.
How to reduce approval risk
- Use trusted apps with verified domains.
- Check whether the wallet prompt says unlimited or high spending limit.
- Use a separate wallet for new DeFi experiments.
- Revoke old permissions after using an app.
- Keep long-term holdings away from wallets used for frequent signing.
Revoking permissions
Revoke tools can show which contracts have permission to spend your tokens. Revoking does not recover stolen funds, but it can reduce future exposure. You still pay network gas to revoke, so prioritize high-value wallets and tokens first.
Before using DeFi, read what DeFi is and smart contracts and gas fees.
FAQ
Does connecting a wallet give spending permission?
Usually no. Connecting lets a site see your address. Spending permission normally requires a separate approval or signature.
Can an approval drain all coins?
An approval is usually token-specific. It can expose the approved token, not every asset in the wallet. Malicious signatures can be broader, so read prompts carefully.
Should I revoke every approval?
Not always. Revoke permissions you no longer need, especially unlimited approvals on wallets holding meaningful balances.