Token approval

A token approval is a transaction that grants a smart contract permission to transfer a specified amount of an ERC-20 token out of the approving wallet.

Before a contract — a DEX, bridge or payment router — can move a wallet's ERC-20 tokens, the wallet must send an approve call setting a spending limit for that spender. The result is an allowance the contract can draw against until it is exhausted or revoked. Because a stale or unlimited approval is a standing risk, our wallet-analytics reads let you enumerate active approvals per address, decode the underlying transaction, and simulate a revoke before broadcasting it non-custodially.