Approving max token balances forever is a security risk. With Permit2, token approvals expire every 30 days and can be reauthorized with a gasless signature. Every time we upgrade our router, users have to spend gas to re-approve tokens. But not anymore! With Permit2, you'll need to re-approve now, but never again.
Permit2 is open source! You can integrate it for:
1. Shared approval management across applications
2. Universal permits for any token
3. Time-bound token approvals
4. Batch approvals & revokes for tokens
https://uniswap.org/blog/permit2-and-universal-router