Shellr

You buy a sealed pack for a fixed price in ETH. You tear it open. Several memcoins fall out, in your wallet, on Robinhood Chain. Keep them, or sell them back on the spot.

That is the whole product. Everything in these repositories exists to make two claims about it true rather than advertised:

The pack cannot be rigged after you buy it. Robinhood Chain has no Chainlink VRF, so randomness here is commit-reveal. The operator queues a batch of keccak256(secret) commitments before anyone buys. Your pack takes the next one at the moment of purchase and mixes in a seed you chose. Neither side can steer the result: the operator was committed before your seed existed, and you never saw the secret. After the pack settles, the secret is in the reveal calldata and anyone can recompute the draw from public data.

The house edge is arithmetic, not vibes. A pack does not spend your stake. It spends your stake times a multiplier drawn from the same seed, across seven bands. The odds of each band and the ends of each multiplier are public state on the contract, so they can be read directly rather than taken on trust, and expectedPayoutBps in the SDK turns them into the mean they imply. Read them off the chain: what a README claims and what the contract enforces are two different things, and only one of them decides your pack.

Five fixed tiers, plus a Pons Pack that prices itself off whatever stake you name and can only reach coins launched on the Pons launchpad. Packs can also be paid for in $SHELLR at a 30% discount, in which case the contract keeps the token and funds the pack out of its own bankroll instead of swapping.

The one worth reading first is shellr-sdk. It contains a mirror of the contract's draw, which means the fairness claim above is something you can run rather than something you have to believe.

import { createPublicClient, http } from "viem";
import { robinhoodChain, readDrawConfig, readPack, verifyPack } from "@shellr/sdk";

const client = createPublicClient({ chain: robinhoodChain, transport: http() });

// Addresses are yours to supply - the SDK ships none.
const config = await readDrawConfig(client, packsAddress);
const pack = await readPack(client, 1337n, packsAddress);

const { ok, reason, drawn } = verifyPack(pack, config);
//  ok    -> the revealed secret hashes to the commitment queued before the buy,
//           and the recomputed draw matches what the contract paid out
//  drawn -> which coins, at what multiplier, for how much each

None of these contracts have been audited. They hold buyer ETH between buy and reveal and they approve a router to spend it. That is why maxStake ships at 0.25 ETH and why pause() exists. Both are load-bearing, not decorative.

Two more things that are true and are easier to say here than to discover:

• A pack is a gamble. The expected return is under what you paid, on purpose, and that is how the thing is funded. Do not buy packs with money you need.
• The keeper's key is hot and MASTER_SECRET is not rotatable. Every commitment already on chain was derived from it. Losing it refunds every pack in flight; leaking it lets someone predict a pack before buying it. They still cannot change the outcome, but they can wait for a good one.

Found something? SECURITY.md.

_{shellr.trade · @shellr_co}