schema.graphql

type Account @entity {

  id: ID!

  transfers: [Transfer] @derivedFrom(field: "from")

}

type Transfer @entity {

  id: ID!

  amount: BigInt

  to: Account!

  from: Account!

}

type Call @entity {

  id: ID!

  module: String!

  method: String!

  parentCall: Call

  childCalls: [Call] @derivedFrom(field: "parentCall")

}