Package nft is the Launchpad collection ledger. Each collection is a GRC721 token whose transfer mode, royalties and metadata rules are fixed at creation. Collections are created, and their tokens minted, only by issuer realms: the Launchpad drops realm and any realm the config admin adds. Holders move, approve and burn their own tokens. The ledger has no admin of its own: nothing here can move a holder's token or change a collection's terms, and a paused lane stops only new collections and new mints.
Epoch returns the ID of a token's current custody: a new one at every move and every change of its single-token approval (the same approval again changes nothing), never one given before; 0 for a retired token. A market binds an order to it, so the order dies with the custody it was made under.
gnokey query vm/qeval -remote "https://rpc.gno.land" -data "gno.land/r/samcrew/launchpad/nft/v1.Epoch(,)"