Readers

A reader method is immutable, and any updates you make to the passed in state argument are ignored.

A reader method gets passed a context of type ReaderContext. A ReaderContext can only be used to make calls to other reader methods.

Here's an example of a reader method called Balance on our Account state that returns the account's current balance:

Python

async def Balance(
    self,
    context: ReaderContext,
    state: Account.State,
    request: BalanceRequest,
) -> BalanceResponse:
    return BalanceResponse(balance=state.balance)

TypeScript

async balance(
  _context: ReaderContext,
  state: Account.State,
  request: BalanceRequest
): Promise<PartialMessage<BalanceResponse>> {
  return { balance: state.balance };
}