Token approval

Permission for an app to move your tokens. Old, unlimited approvals are a common way funds get drained.

When you use a token with an app, you first approve the app's smart contract to move that token from your wallet. Approvals don't expire, and many are set to an unlimited amount.

If the approved contract is malicious or later hacked, it can use the approval to take your tokens. Reviewing and revoking old approvals is one of the best habits in crypto security.