Automatic transfer from ERC-20 token wallet.

[Si9ma]

Im a web developer, im trying to code a feature that upon completion of a task, a user is credited with a set amount of tokens to his wallet. Basically a reward in ETH upon demand of the server, is there a way i can do this? Do i need to have a centralized wallet which will send coins to the user, if so is there an API? Otherwise is there a simpler way to do this such as directly getting the coins from the blockchain?
Thanks in advance

[Quickseller]

You will most likely need to run an implementation of an etherum node that accepts RPC calls. The specific calls you will have to make in order to create/sign a transaction will depend on the client implementation you are running.

Depending on the values involved, you may also consider crediting tokens to a database balance for the user, and allowing the user to withdraw upon certain criteria being met. Anytime you move a token to a user's ETH address/"wallet", you will have to pay a gas fee.