To better understand the legality and “grey area” around psilocybin aka magic mushrooms, you’ll need to compare it to Cannabis’ road to legalization. At the moment, Cannabis is legalized in approximately 20 or so states after first being declared decriminalized - however on a federal level Cannabis is still a Schedule I substance.
The current state of psilocybin is best thought of as a few years behind Cannabis as it follows the same blueprint from decriminalization to legalization. The first state, Colorado (same as Cannabis) lead the way with decriminalization of the psilocybin, now we see Washington DC, Oregon state (legalized for medical use), Seattle, Detroit, Oakland, Santa Cruz, and more having decriminalized the substance.
Proposals for the states of California, Washington, Massachusetts, and several others have been put together by policymakers as well and are hopeful in passing in the very near future. At the moment Psilocybin is still a Schedule I substance like cannabis.
Schedule35 operates from a decriminalized zone and still advises that all sales are up to customer discretion and advises customers to be aware of their municipal and state laws.