vendure/server/src/api/customer/customer.api.graphql

type Query {
  customers(options: ListOptions): CustomerList!
  customer(id: ID!): Customer
}

type Mutation {
  "Create a new Customer. If a password is provided, a new User will also be created an linked to the Customer."
  createCustomer(input: CreateCustomerInput!, password: String): Customer!
  "Create a new Address and associate it with the Customer specified by customerId"
  createCustomerAddress(customerId: ID, input: CreateAddressInput): Address!
}

type CustomerList implements PaginatedList {
    items: [Customer!]!
    totalItems: Int!
}