Three things shipped since yesterday, all in the repo.
1. The token does something now. A deposit pays 0.5%, held on its own address.
Burn KEEPHOST and you get a key: that wallet never pays the fee again. Those fees pay the relayer at withdrawal — so a withdrawal returns the whole denomination, funded by the people who did not burn.
2. Any SPL token can have a pool. Same tree, same circuit, same proof, same relayer; the vault becomes a token account owned by an address with no private key. Tested with a mint shaped like USDC.
3. The program went from 518 kB to 437 kB by talking to the token program directly instead of through a library. On Solana that is rent paid for ever it halved the cost of the upgrade.
Every line of it passes an end-to-end test against the exact binary that will be deployed: deposit, proof, withdrawal, and the same receipt refused twice.
github.com/KeepHost/system