What is a wallet approval, and how to revoke one

Quick answer: a wallet approval (also called a token approval or allowance) is permission you give a smart contract to move a specific token from your wallet. An unlimited approval lets it move any amount and never expires. You can review your approvals and revoke any you no longer need, which sets that permission back to zero.

What an approval is

Many apps cannot move your tokens until you allow them to. You sign an approval once, and the app can then move that token up to the amount you allowed, whenever it needs to. This is normal for swaps and other apps you use on purpose.

Limited and unlimited approvals

A limited approval allows a set amount. An unlimited approval allows the largest amount a token can represent, which is far more than any wallet holds, and it does not expire. Apps often ask for unlimited approvals by default to save you a step. That is convenient, and it is also why a forgotten approval is a risk: if that contract is ever compromised, or the page was fake, the permission is still there.

How drainers use approvals

A "claim" or "verify" page asks you to sign something that looks routine. The signature grants a scammer's contract permission over your tokens, and the tokens are moved later, sometimes days after you left the page. Some approvals are given by signing a message rather than sending a transaction, so a signature can matter even when no fee is charged.

How to check your approvals

1. Open your wallet's own help page for approvals and follow its link, instead of searching and clicking an ad. For example, MetaMask explains this at https://support.metamask.io/more-web3/learn/how-to-revoke-smart-contract-allowances-token-approvals/
2. Connect only to a checker you reached from a trusted source: your wallet, or your chain's block explorer.
3. Look for approvals to spenders you do not recognise, approvals for tokens you no longer hold, and unlimited approvals you do not need.

How to revoke

Revoking means setting the allowance for that spender back to zero. It is a transaction, so it usually costs a small network fee. After you revoke, that contract can no longer move that token. If you will use the app again, it will ask you to approve again, and you can choose a limited amount.

Habits that keep it small

• Approve only the amount you need when the app lets you.
• Use a separate wallet for anything new or for airdrops. Keep your main funds elsewhere.
• Read every signature request, and never sign one you do not understand.
• Review approvals every few months, and straight after any suspicious site or message. Our Telegram scams guide shows the common traps: https://mintgraph.org/blog/telegram-airdrop-scams-7-signs-and-what-to-do

What MintGraph does

When a note involves a wallet connection, the note says what the page asks you to approve. If we cannot see it, we say that. A claim that needs more permission than it should is labelled RISK.

This is research and safety guidance, not financial advice. Rewards are never guaranteed.