Sentinel

Sentinel is a Token-2022 Transfer Hook program that enforces customizable compliance rules atomically on every token transfer — no off-chain monitoring, no backend approval queue, no centralized gatekeeper. When a wallet calls transfer_checked on a Sentinel-protected mint, Token-2022 CPIs into Sentinel before the transfer settles, evaluating the sender's on-chain compliance record against an upgradeable ruleset and allowing or reverting the transaction atomically.

Nine rule types ship in the engine: allowlist, blocklist, velocity limits, KYC expiry, jurisdiction blocking, transfer caps, cooldowns, time windows, and minimum floors. Configs, rulesets, and per-wallet compliance records are modelled as PDAs, and 15+ LiteSVM test cases run in-process without spinning up a local validator.