What is the right way to remove a transaction-payment-pallet from the runtime?

Question

After going through some of the posts here, as an experiment I tried removing the transaction-payment-pallet from the construct_runtime! to test if that would set all transaction fees to zero. However, cargo build threw an error saying the impl of the pallet is required for the Config trait of some primitive.

Is there a right way to remove this pallet, or say in the example above, will I be required to go through the code more manually?

Answer 1

The transaction payment pallet is not that easy to remove since it is used in a lot of different parts of the runtime. If you goal is to remove this pallet, indeed you will need to go through the code of the runtime more manually, and remove all uses of it.

However, if your goal is just to make everything zero fees, you can do that by updating your config of the pallet's WeighToFee and LengthToFee types.

Easiest is probably to use ConstantMultiplier: https://paritytech.github.io/substrate/master/frame_support/weights/struct.ConstantMultiplier.html

Then set the multiplier to zero.

use frame_support::weights::ConstantMultiplier; // ADD THIS TOO
impl pallet_transaction_payment::Config for Runtime {
    type RuntimeEvent = RuntimeEvent;
    type OnChargeTransaction = CurrencyAdapter<Balances, ()>;
    type OperationalFeeMultiplier = ConstU8<5>;
    type WeightToFee = ConstantMultiplier<Balance, ConstU128<0u128>>;
    type LengthToFee = ConstantMultiplier<Balance, ConstU128<0u128>>;
    type FeeMultiplierUpdate = ConstFeeMultiplier<FeeMultiplier>;
}