Most wallets ask "are you sure?" at the end, when you have already decided. The Sentinel speaks at the start: it screens a destination address the instant it is pasted, before an amount is entered, while stopping still costs you nothing. It is built into the B28 wallet and it runs on every send.
The Sentinel is part of the wallet rather than a separate product or a paid add-on. It is on by default, it cannot be switched off, and it runs on every send — including the first one you ever make.
What it catches
- Known-malicious addresses. It checks the address you are sending to against known-risk signals and flags anything dangerous.
- Address poisoning and look-alikes. Scammers seed your transaction history with addresses that closely resemble ones you have used, hoping you copy the wrong one later. The Sentinel detects a destination that is suspiciously similar to, but not the same as, an address you trust.
- Honeypot tokens. Tokens built so you can buy in but never sell out. It screens for the pattern before you interact.
- Drainer approvals. Many thefts are not transfers at all — they are approvals that quietly hand a contract permission over your tokens, and drain it days later. The Sentinel flags drainer-style approvals so you can refuse them.
- A pause on risky sends. A confirmed threat cannot be silently clicked through, so a scammer cannot rush you past it.
Why the timing is the point
A warning shown at the final confirm screen arrives after you have committed — you have chosen the recipient, typed the amount, and built up momentum. Interrupting yourself then feels like undoing work. Screening at paste time means the check lands before any of that exists, which is the moment a person is still genuinely willing to stop. That ordering is the design decision, and it is the part other wallets generally do not copy.
What it is not
The Sentinel is a safety aid, not a guarantee. New scams appear constantly and no screening catches everything. Treat its warnings seriously, and treat its silence as a reason to stay careful rather than a promise that you are safe.
Address and token reputation checks — look-alike, honeypot and drainer screening — run on the networks we support them for, which are the EVM networks such as Ethereum and its L2s. On other networks the Sentinel still shows you the transaction and tells you when it cannot verify a recipient, so you never get a false all-clear.
It also never signs anything. It does not move money, it does not hold your keys, and it cannot stop you approving a transfer you insist on. It makes sure you see the risk first.
See it behave
There is a rough working demo of the Sentinel's states at /sentineltest. It is a design prototype rather than a product page, so treat what it shows as illustrative.
Read further
For the scams it is built against, see scams and how to spot them. For the security model it sits inside, see the security overview and how self-custody works. Because B28 is non-custodial, on-chain transactions are final: nobody, including us, can reverse one after it confirms. That is precisely why a check that arrives early matters more than one that arrives late.