Simple on-chain access controller contract. This contract permit an on-chain registration mechanism with a concept of slots.

Owner can specify a number of slots (maxSlotsCount). Everyone is able to register to get a slot. When the slotUsedCount eq the maxSlotsCount there is no more space to register.

With this simple approach you can use an on-chain contract to manage accesses of your contracts or even of your frontends. This is a very useful tool when you want to give progessive access.

The contract has three state variables:

@storage_var
func AccessController_maxSlotsCount() -> (max: felt):
end

@storage_var
func AccessController_slotUsedCount() -> (entries: felt):
end

@storage_var
func AccessController_whitelist(address: felt) -> (whitelisted: felt):
end

When deploying the contract you have to pass two args:

(
    initial_allowed_access: felt, # Number of initial slots available
    owner_address: felt           # Owner of the contract who will be able to increase # of slots
)

Once you deployed the contract, you can increase the number of maximum slots available. To do that make a transaction by invoking the increaseMaxSlots function from the owner wallet. The argument is increase_max_slots_by which is the number of slots you want to add.

Other useful functions can be found here

Using this contract is deadsimple. First of all import ABI and create your Contract object:

import { Contract, json } from "starknet";

const compiledARFController = json.parse(JSON.stringify(arfControllerAbi));
arfControllerContract: new Contract(
    compiledARFController,
    CONTROLLER_CONTRACT_ADDRESS
);

Verify if an address is allowed/registered:

accessControllerContract
    .isAllowed("0x1234...6789")
    .then((response: CallContractResponse) => {
        // response.is_allowed
    })

Permit a user to register in order to get a free slot:

accessControllerContract
    .invoke("register", [])
    .then((response: AddTransactionResponse) => {
        // Transaction added
    }).catch(() => {
        // Error
    });

Check the number of available slots:

accessControllerContract
      .freeSlotsCount()
      .then((response: CallContractResponse) => {
        // response.free_slots_count
      })

This contract has been used for Alpha Road during the first Testnet phases of the launch of our first offering: a one-click revisited AMM.

First, install requirements:

pip install -r requirements.txt
pip install -r tests/requirements.txt

Run all tests:

pytest

Run a specific test:

pytest tests/test_AccessController.py -k test_transfer_ownership_should_fail_when_caller_is_not_owner

To make our tests readable we use a standard linter: flake8

Run linter:

flake8 . --count --exit-zero --max-complexity=10 --max-line-length=120 --statistics

Flake will only act as linter and will not help you to fix/format your python files. We recommend using: yapf

E.g:

yapf --recursive --style='{based_on_style: pep8, column_limit: 120, indent_width: 4}' -i tests

Feel free to improve this by providing a PR.