Permit2 is a Solidity library that adds a low‑overhead, signature‑based approval and meta‑transaction layer for any ERC‑20 token, enabling single‑transaction permit flows, batched approvals, time‑bound allowances, and one‑time signed transfers without on‑chain approvals. It is aimed at dApp and protocol developers who want safer, more flexible token permissions and seamless integration with existing contracts (e.g., Uniswap) across the Ethereum ecosystem.