Mintproof identifies trading cards and shows prices gathered from third-party sources. It is an information tool. It is not a marketplace, a broker, an appraiser or a dealer. It does not buy, sell, list, ship or hold cards, and it never takes possession of anything you own.
Prices shown are observations from other marketplaces, labelled with their source and date. They are not an offer, an appraisal, or a guarantee of what a card will sell for. Mintproof does not tell you to buy, sell, or grade anything. Decisions about your cards are yours, and so are the outcomes.
Raw and per-condition prices come from TCGAPIs. Graded prices come from PriceCharting. Every figure in the app is labelled with which of three things it is:
Nothing in the app is an appraisal or an offer. Where the two sources disagree they are measuring different things and the app does not blend them.
Only figures labelled PSA 10 are specific to PSA. Rows labelled Grade 9, Grade 8 and so on are prices for a card graded at that number by any grading company, which is how the underlying source measures them. A grading company’s judgement is its own and Mintproof has no relationship with any of them.
Return estimates are arithmetic on figures you supply — the graded sale prices you look up and the gem rate you choose — against the raw price of the card and the submission fee you select. Mintproof has no population data and does not predict what grade a card will receive. It shows what a given grade would have to be worth to cover the fee; the decision is yours.
Where the app projects a price forward it says so on the same screen, states the method, and shows a range rather than a single number. A projection is arithmetic on past prices. It is not a forecast, not advice, and nothing guarantees that past movement repeats.
An account is optional; the app works without one. Keep your sign-in details to yourself — you are responsible for activity under your account. You can delete it at any time from Profile → Delete my account, which removes your sign-in and email permanently. Your collection lives on your device and stays until you delete the app.
Do not scrape the service, resell its data, redistribute the price data as a feed, or attempt to break its access controls. The price data is licensed to us and not sub-licensable to you.
The app depends on third-party price providers. If one is unavailable the app will say so rather than show a stale number as current. We do not guarantee uninterrupted service and we may change or withdraw features.
Mintproof is independent and is not affiliated with, endorsed by, or sponsored by Nintendo, Creatures Inc., GAME FREAK inc., or The Pokémon Company. Pokémon and all related names are trademarks of their respective owners. Mintproof is our own name and is not a term used by any grading company or card publisher.
Written against what the software actually does. It is not legal advice and has not been reviewed by a lawyer. Before store submission it needs review for the jurisdictions the app will be sold in, and in particular: the limitation of liability and warranty position, which is deliberately not asserted here because it should be drafted rather than borrowed; and confirmation that the price providers’ own licences permit display in a paid consumer app.