How Deckbots is built, what it can and cannot do, and the addresses to verify any of it yourself.
Deckbots is two pieces. On-chain, a vault contract per user holds funds and cards. Off-chain, a bot decides what to trade and asks the vault to execute it. The vault does not trust the bot; it verifies.
Created by the factory, one per wallet, numbered in the order they are created. You are the owner, written into the contract at deployment and immutable afterwards.
These are properties of the code, not promises. Each has a test written as an attack that must fail:
When the bot lists a card it chooses only the price. The vault builds the order itself and writes the proceeds recipient — always the vault. The bot decides how much; it never decides who gets paid.
Fair value for a card comes from completed sales of the same card: same category, set, card number, variant and language, then matched on grader and grade. A CGC 9 and a PSA 10 of one print are different assets and are priced separately.
The model is deliberately hard to convince:
Cross-grade matters: valuing a PSA 9 from PSA 10 sales would make the bot overpay, while the reverse only makes it miss a deal. It only ever errs in the direction that costs you nothing.
Trades settle on OpenSea's Seaport contract, the only permissionless venue for these cards. Courtyard's own marketplace matches orders off-chain and relays them, so no bot can reach it.
When the bot relists, it undercuts fair value rather than matching it. Close to half of all priceable cards show every recent sale at one identical price — a seller with inventory at a fixed ask. Matching that price means queueing behind them indefinitely.
Polygon mainnet, chain ID 137. Verify any of this yourself:
Cards can lose value. The bot estimates worth from past sales. Past sales are evidence, not a guarantee.
Cards sell slowly. Capital can sit in inventory for a long time. Withdrawing while the bot holds cards returns those cards, not their cash value.
Smart contracts can have bugs. These are tested and the guarantees above are enforced in code, but no contract is beyond error. Deposit only what you can afford to lose.
Nothing here is financial advice.
Deckbots