does it not require any preshared keys?

That's they way. And no, it does not require preshared keys: each test should use a random generated key to achieve test isolation. In serve testing mode each preshaped keys becomes like its own isolated spicedb

@vroldanbet we have load the schema only once for all the tests?

No. Each preshared key is an isolated environment, so you'd have to write the schema and relationships again

Ok so the only thing is that it can be done on a single spice-db image on docker

I don't understand what you mean

i am talking about : spicedb serve-testing

Yes. You only need one container, then each test used a different randomly generated preshared key to achieve test isolation