DeFi and tokens

Approvals in DeFi: DEX swaps and lending without needless risk

Updated 3 min read

In short

  • A DEX or lending protocol needs an approval to take your token into a trade. That is normal.
  • An open-ended approval for the full amount is dangerous: if the contract is hacked or replaced, it takes the whole balance.
  • Approve the amount of the trade and revoke it once you stop using the service.

Why DeFi needs an approval

TRC-20 tokens cannot simply be “sent” to a swap contract in a way it notices. So the flow has two steps:

  1. approve — you allow the contract (a DEX router, a lending pool) to take up to N tokens;
  2. the trade — the contract itself pulls the amount it needs via transferFrom.

The approval lives in the token contract until you revoke it. More on the mechanics — unlimited approvals.

Where the risk is

  • Unlimited amount. Many interfaces offer the maximum by default so they do not have to ask twice.
  • A hack or protocol upgrade. If the contract can be upgraded, the new logic inherits the old approvals.
  • A fake interface. A copy of a DEX site asks for an approval not for the router but for the scammer’s address, see phishing sites and dApps.
  • Forgotten approvals. A year later you no longer remember who you allowed and how much.

How to use DeFi more safely

  • In the confirmation window change “unlimited” to the trade amount if your wallet allows it.
  • Keep a separate wallet for DeFi and your main savings on an address with no approvals.
  • After leaving a pool or repaying a loan, revoke the approval.
  • Check unfamiliar protocols’ contracts in /check before the first deposit.

How to check and revoke

Open GuardPay /revoke and paste your address. You will see every approval on your USDT — to whom and for how much — read straight from the token contract. Revoking happens in your wallet, one signature per approval. It costs a little energy or TRX, see energy and fees.

Check and revoke approvals

Who you allowed to spend your USDT, read live from the contract. Revoke in your own wallet: one signature per approval, your keys stay with you.

Check approvals

FAQ

If I revoke an approval, will my money in the pool disappear?

No. Revoking does not touch what is already deposited. You can still withdraw from the pool after revoking; for a new deposit the service will ask for a new approval.

Is an approval to a large, well-known protocol safe?

Safer than to an unknown one, but not risk-free: well-known protocols get hacked too. Approving only the trade amount limits the possible damage.

This guide explains how schemes work and how to protect yourself. It is not legal or financial advice.

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