Why

identity.schemas

is a required parameter during docker run, when I could create identities later with SDK after starting kratos?

I will guess that it's because you need a default schema for the self service flows and doing that dynamically will add more complexity

Review this: https://www.ory.sh/docs/ecosystem/configuring When configuring array values via env vars, the format is a bit different. You probably need something like this: IDENTITY_SCHEMAS_0_ID=<id of your schema> IDENTITY_SCHEMAS_0_url=base64://...... or you could do it like this: IDENTITY_SCHEMAS='[{id: "id of your schema", url: "base64://...."]' You need a schema defined in order to later create identities that follow that schema.