EOS project: json mandatory, optional schame difference
{ type: "object", properties: { name: { type: "string" }, age: { type: "integer", minimum: 0 }, email: { type: "string", format: "email" }, address: { type: "object", properties: { street: { type: "string" }, city: { type: "string" }, postalCode: { type: "string" } ...