An onchain permission check for Robinhood Chain: before value moves, a contract can refuse a token whose verdict is missing, unknown, stale or unsafe.
ShieldBot is a risk permission layer for Robinhood Chain. It watches new token launches, simulates a buy and a sell on supported routes, and answers UNKNOWN instead of SAFE when it cannot settle a question. The Robinhood Chain verdicts it records go to a public registry together with the hash of their evidence document, so anyone can check the exact bytes behind a verdict.
A deployed guard turns that record into a yes or no that any contract can call. It allows only a recent LOW or MEDIUM verdict, and it denies one that is missing, UNKNOWN, high risk, honeypot, expired or dated in the future. A guarded transfer pinned to Paxos USDG shows an app action that goes ahead only when the guard says yes.
The problem: on a young chain, people buy tokens they later cannot sell, and most risk tools hand back a score that an app cannot act on. A gap in the evidence can also quietly read as safe. ShieldBot treats missing evidence as unknown, and puts the decision where an app can enforce it: in the same transaction that moves the money.
Contracts on Robinhood Chain (4663), source verified: ShieldBotVerdictRegistry 0xB7cfB87579f232dBa70CDC8Ba063AA7b500D5138 (records each verdict with its evidence hash; OpenZeppelin Ownable2Step), ShieldBotVerdictGuard 0x47fbF2cfcb98B02Ffbc50037A9A65072c58b129e (check(subject, maxAge) returns allowed and a reason code), and ShieldBotGuardedTransfer 0x336254bA85406D9af39357101b688E2B757751b3 (moves its pinned USDG only when the guard allows the subject; OpenZeppelin SafeERC20 and ReentrancyGuard). The Foundry suite has 114 tests.
Try it in ten minutes: the judge guide replays a recorded honeypot offline, runs the guard's decisions, and checks a live verdict against its onchain record through an independent RPC, with no API key, wallet or signing: https://github.com/Ridwannurudeen/shieldbot/blob/main/docs/JUDGE_GUIDE.md
Honest limits: the recorder is trusted, so a match proves the recorder committed those exact evidence bytes, not that the scan was right. Freshness counts from publication, and only actively watched tokens stay fresh. The simulation covers supported routes; anything else stays UNKNOWN. We do not claim a live guarded USDG payment.
ShieldBot existed before the buildathon as a multichain transaction scanner. Everything specific to Robinhood Chain was built during the buildathon: the chain adapter and launch discovery; a buy and sell simulation over eth_simulateV1 for supported Uniswap routes, including Doppler pools quoted in USDG; a check that flags tokens passing themselves off as one of Robinhood's official stock tokens; canonical evidence documents and onchain verdict publication; and the verdict registry, the guard and the guarded USDG transfer, all deployed on Robinhood Chain on 27 September.
We also added our own sell simulation on Arbitrum One, and made sure a simulation that cannot settle a token leaves it UNKNOWN rather than safe.
At the time of writing, main has 221 commits inside the buildathon window, starting after commit c1d1adf on 13 September: https://github.com/Ridwannurudeen/shieldbot
OPEN TO RAISING FUNDS